Pregnancy Rates In Women Research Articles

The Role of Nutrient Supplements in Female Infertility: An Umbrella Review and Hierarchical Evidence Synthesis.

Nutrient supplements are commonly used to improve fertility outcomes by women with infertility trying to conceive spontaneously or utilising medically assisted reproduction (MAR). However, despite their widespread use and perceived safety, there is a lack of clear guidance on the efficacy and safety of these supplements for female infertility. The aim of this umbrella review was to identify the best available and most recent evidence on the efficacy and safety of nutrient supplements for female infertility to provide evidence-based guidance for clinicians and reproductive couples. Five electronic databases were searched for umbrella reviews, meta-analyses, and systematic reviews of randomised controlled trials on nutrient supplements for female infertility, published from August 2017 to January 2024. The primary outcomes were live birth, and clinical and biochemical pregnancy rates. Secondary outcomes were adverse effects including miscarriage and ectopic or multiple pregnancy. Quality assessment was performed using the A MeaSurement Tool to Assess systematic Reviews Version 2.0 (AMSTAR 2), and the certainty of evidence for outcomes were assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, where possible. Four meta-analyses were included. Multiple micronutrients and antioxidants increased live birth rates in women utilising MAR and/or trying to conceive spontaneously compared to placebo, standard or no treatment (odds ratio (OR) 2.59 and 1.81 respectively) with very low certainty evidence. L-carnitine, coQ10, melatonin, myo-inositol, NAC and vitamin D increased clinical pregnancy rates in women with PCOS and/or undergoing MAR compared to placebo, standard or no treatment (odds ratio (OR) 11.14, 2.49, 1.66, relative risk (RR) 1.52, OR 2.15, and 1.49 respectively) with very low certainty evidence. Vitamin D did not increase biochemical pregnancy rates in women utilising MAR with very low certainty evidence. NAC, vitamin D, and pooled antioxidants had no effect on miscarriage rates or multiple pregnancy rates in women trying to conceive spontaneously or utilising MAR, with low to very low certainty evidence. Pooled antioxidants had no effect on ectopic pregnancy rates in women trying to conceive spontaneously or utilising MAR, with low certainty evidence. The available evidence is insufficient to recommend nutrient supplementation to improve female infertility in women trying to conceive naturally and those utilising MAR. However, there is currently no indication that these nutrients pose any risk of significant harm. PROSPERO (CRD42022365966) 20 October 2022.

Comparing intra-uterine injection of mononuclear cells and platelet-rich plasma on the pregnancy rate of women with recurrent implantation failure: An RCT

Background: Recurrent implantation failure (RIF) can be explained mainly by improper crosstalk between the embryo and endometrium. The T-helper1/T-helper2 profile balance influences effective embryo implantation. Endometrial immunomodulation via intrauterine injection of activated peripheral blood mononuclear cells (PBMCs) or autologous platelet-rich plasma (PRP) is a potentially efficient treatment option. Objective: This study aims to examine the biochemical and clinical pregnancies resulting from the intrauterine administering of activated PBMCs and PRP in RIF women. Materials and Methods: This randomized clinical trial study was done in the Rooya Infertility Treatment Center, Qom, Iran from November 2022 to April 2024. 96 women with at least 2 RIFs were randomized into control, PBMC, and PRP groups. Briefly, 3 ml of blood sample was collected and PBMCs were isolated using Ficoll separation solution, and cultured for 72 hr. PRP was separated from 10 ml of peripheral blood through centrifugation. 2 days before embryo transfer PBMCs or PRP were transferred into the endometrial cavity. Results: Except for the duration of infertility, which was higher in the PBMC group, all other baseline characteristics were not statistically different. Moreover, a significantly higher rate of biochemical pregnancy was observed in the PRP (10/32) and PBMC (12/32) groups compared to the control (3/32) (p = 0.027), while the rate of clinical pregnancy was only significantly higher in the PBMC group (10/32) than in the control group (2/32) (p = 0.038). Conclusion: Neither PBMC nor PRP interventions exhibited a substantial advantage over one another regarding biochemical and clinical pregnancy rates.

Bushen Huoxue decoction improves the reproduction of endometriosis-associated infertility by regulating Homeobox A10 and αlpha(v)beta(3) integrin expression.

To investigate the mechanism of Bushen Huoxue decoction (, BSHXD) to treat endometriosis-induced infertility. The main compounds of BSHXD were determined by high performance liquid chromatography-mass spectrometry (HPLC-MS/MS). The effect of BSHXD on Homeobox A10 (HOXA10) and alpha(v)beta(3) (αvβ3) integrin expression of Ishikawa cells, mouse model, and endometriosis-associated infertility women was evaluated by using Western blot analysis, immunohistochemistry and Real-Time quantitative polymerase chain reaction (RT-qPCR). The efficacy of BSHXD on embryo attachment were examined by using the BeWo spheroid and mouse embryo attachment assay. HOXA10 concentration in uterine flushing fluid of endometriosis-associated infertility women treated with BSHXD was measured by Enzyme-Linked immunosorbent assay (ELISA). BSHXD improved BeWo spheroid and mice blastocysts attachment to Ishikawa cells and increased embryo implantation rates in mice and pregnancy rates in women with endometriosis-associated infertility. BSHXD enhanced HOXA10 and αvβ3 integrin expression in Ishikawa cell, endometriosis mouse model, and endometriosis-associated infertility women, which potentially improved endometrial receptivity. BSHXD could improve endometrial receptivity of endometriosis-associated infertility in a dose-dependent manner by regulating HOXA10 and αvβ3 integrin expression.

Outcomes of first assisted reproductive technology treatment in infertile women with and without antinuclear antibodies: A prospective cohort study

BackgroundIt has been shown that antinuclear antibodies (ANAs) are associated with adverse reproductive events. The presence of ANAs may reduce the pregnancy rate in women undergoing assisted reproductive technology (ART) treatment. MethodsThis study aimed to investigate the potential effect of ANAs on the outcomes of infertile women undergoing in-vitro fertilization and embryo transfer (IVF-ET) or intracytoplasmic sperm injection (ICSI) for the first time. In total, 907 women were enrolled, with 192 (21.14 %) cases in the ANA+ group and 715 (78.86 %) cases in the ANA- group. Baseline data were collected, and associations between ANAs and oocyte maturation rate, high-quality embryo rate, clinical pregnancy rate, live birth rate and miscarriage rate were analysed. ResultsCompared with the ANA- group, the ANA+ group had a considerably lower oocyte maturation rate (0.69 ± 0.31 vs 0.77 ± 0.26; P = 0.003) and a lower high-quality embryo rate (0.53 ± 0.30 vs 0.78 ± 0.92; P < 0.01). ANAs had no effect on clinical pregnancy rate, live birth rate and miscarriage rate in infertile women receiving ART for the first time. ConclusionsThese findings suggest that ANAs reduce oocyte maturation rate and high-quality embryo rate in infertile women undergoing IVF-ET/ICSI for the first time, but do not have a significant effect on clinical pregnancy rate, live birth rate and miscarriage rate. When testing for ANAs is part of the planned treatment protocol, this should be undertaken in advance of starting IVF-ET/ICSI.

Use of Laughter Therapy for In Vitro Fertilization: A Systematic Review

Background/Objectives: In vitro fertilization (IVF) is an assisted reproductive technique for women and couples experiencing difficulties in achieving a spontaneous pregnancy, often due to stressors that negatively affect fertility. Humor can be beneficial in these stressful situations, helping to reduce symptoms of anxiety and depression. The primary aim was to analyze the effectiveness of laughter therapy in increasing pregnancy rates in women undergoing IVF. The secondary aims were to identify different types of laughter therapy interventions and evaluate their benefits. Methods: A systematic review was conducted using Medline, Web of Science, Scopus, Cinahl, ProQuest and Lilacs, with the search terms “laughter”, “laughter therapy”, “fertilization in vitro” and “fertilization”. Intervention studies published in English, Spanish, or Portuguese were included, with no limits on the date of publication. Studies with other designs, those conducted with animals and grey literature were excluded. The quality of the included studies was assessed using the Joanna Briggs Institute critical appraisal tools. Results: In total, n = 3 studies (1 randomized clinical trial and 2 quasi-experimental) were included, evaluating pregnancy rates and symptoms of depression and anxiety. The interventions included clowns performing magic tricks and interpreting comic situations. Additionally, they incorporated hand clapping, breathing exercises, childlike playfulness, drinking milk, muscle relaxation exercises, candles, and music. Conclusions: This review does not provide clear evidence on the effectiveness of laughter therapy in increasing pregnancy success in IVF. Although it may have some positive effects in reducing symptoms of depression and anxiety, it is important to note that while the reduction of these symptoms may enhance the emotional well-being of patients, it has not been demonstrated to directly lead to an increase in pregnancy rates. Laughter therapy is an innovative, non-pharmacological intervention that is simple, non-invasive, easy to implement and cost-effective; however, the number of available studies is insufficient. More research is needed to provide better and higher-quality evidence using rigorous designs to evaluate this intervention in IVF clinical practice.

A Significant Correlation of Glutamine and Interlukin-6 with Pregnancy Rate in Women Undergoing ICSI

Background: The composition of follicular fluid (FF) is significantly influenced by metabolic factors, and the analyses of metabolites in FF could reveal the correlation between metabolites and oocyte quality, embryo development, and pregnancy outcome. FF provides nutrients and growth factors that promote oocyte growth, development, and maturation. Objective: To investigate the relationship between serum and FF glutamine and FF IL-6 levels and their influence on the pregnancy rate in women who are undergoing an ICSI treatment cycle. Materials and Methods: A prospective cross-sectional study was performed on 90 women aged 20- 44 years who underwent ICSI treatment from July 2023 to February 2024. Serum and follicular fluid collected on the day of oocyte pick-up were used as biological material. The embryological laboratory examined the retrieved follicular fluid and collected oocytes using stereomicroscopy. ELISA analysed serum, FF glutamine and FF IL-6. The ICSI method was utilized for fertilization. The pregnancy test is done by measuring serum BHCG. Statistical data processing was conducted using the software package SPSS 23. Results: There was a highly significant correlation between FF glutamine and FF IL-6 (p &lt; 0.001) and a positive correlation between FF glutamine and FF IL-6 with pregnancy rate ( p &lt; 0.001) (p &lt; 0.001 ). Conclusion The correlation of FF glutamine and FF IL-6 affects the pregnancy rate in women undergoing ICSI. FF glutamine and FF IL-6 can be considered predictors for pregnancy while serum glutamine has no significance.

The impact of extremely brief meditation and brief mindfulness interventions on assisted reproductive technologies success rates: A randomised controlled trial

ObjectiveTo investigate the effect of extremely brief meditation (EBMI) or brief mindfulness interventions (Brief MI) on pregnancy rate in women undergoing Assisted Reproductive Technology (ART). MethodsThis is a prospective, three-armed, randomized controlled trial with women undergoing ART cycle, age ranging from 18 to 50 years. In the day of embryo transfer, the patients randomized to Brief MI group received a 15-minute audio of mindfulness. They were instructed to practice it daily, starting from the day of embryo transfer to the day of the pregnancy test, leading to a total of 180–210 minutes. Women randomized to EBMI met once a week during the waiting time between the embryo transfer and pregnancy test day in the same virtual room with a meditator instructor for 40 minutes, totalizing two sessions (80 minutes). The pregnancy rate was assessed via a blood test to measure hCG performed 2 weeks after embryo transfer. ResultsA total of 68 women aged 37.5 ± 4.3y were included (EBMI, n = 24; Brief MI, n = 22 and CG, n = 22). Pearson's Chi-square test and Student's t-test for independent samples showed no significant differences between intervention and control groups. Both EBMI and Brief MI had no significant effect on pregnancy rate in women undergoing ART. ConclusionThis randomized control trial revealed that the extremely brief meditation (EBMI) or self-managed brief mindfulness intervention (Brief MI) had no significant effect on pregnancy rates in infertile women undergoing ART cycles. Trial registration number: NCT04058262.

The effect of music interventions on anxiety, pain, and pregnancy rates in women undergoing fertility treatment before oocyte collection and embryo transfer: Systematic review and meta-analysis of randomized controlled trials

IntrodutionThe present review aimed to evaluate the available evidence in the literature on the effect of music interventions on improving outcomes related to anxiety, pain, and pregnancy rates of women undergoing fertility treatment, prior to oocyte collection and embryo transfer. MethodWe searched the following databases from database inception to 2 May 2024, PUBMED, Embase, Web of Science, and the Turkish Academic Network and Information Center (ULAKBIM). Randomized controlled trials (RCT) in Turkish and English languages were included in the screening. Articles were scanned using MeSH-based keywords. The data were analyzed using the Review Manager computer program (Version 5.4.1). ResultsA total of 8 RCTs, including 1634 female patients, were included in our review. Music interventions significantly reduced anxiety scores prior to oocyte collection or fertilization compared to the control group (Standardised Mean Difference (SMD):0.26, 95 % CI:0.39 to 0.13, Z = 3.91, p < 0.0001). Moreover, after the music treatment, there was a significant improvement in the pain score during the procedure (SMD:0.96, 95 % CI:1.72 to -0.20, Z = 2.49, p = 0.01). Although more women in the music interventions group experienced an increase in the clinical pregnancy rate compared to the control group, there was no evidence of an effect on pregnancy rate (SMD:0.14, 95 % CI:2.63 to 2.34, Z = 0.11, p = 0.91). ConclusionMusic interventions appears to improve anxiety and pain scores in female patients receiving fertility treatment when administered during oocyte collection and fertilization. They may increase the clinical pregnancy rate but this not statistically significant. More research with larger sample sizes is needed to investigate the impact of music interventions on assisted reproductive technology clinical outcomes.

Effects of intrauterine infusion of autologous platelet-rich plasma gel on endometrial thickness and outcomes of frozen-thawed embryo transfer in women with thin endometrium.

The purpose of this study is to determine whether intrauterine infusion of autologous platelet-rich plasma (PRP) gel increases endometrial thickness (EMT) and improves the outcomes of frozen-thawed embryo transfer (FET) in women with thin endometrium. This study included 111 women (aged 25-44years) who had thin endometrium. All patients had at least one previous cycle canceled because of thin endometrium or previous embryo transfer cycles and an EMT < 7mm. Forty-seven women underwent intrauterine infusion of autologous PRP gel on three occasions during endometrial preparation and the remaining women served as controls. The final EMT was measured by ultrasound before the start of the luteal phase, and FET-related outcome parameters were monitored. Mean EMT was greater in women who received PRP gel than in those who did not (6.7mm vs. 6.3mm, respectively, p < 0.05). FET was attempted in all women. The 47 women who underwent infusion of PRP had a significantly higher pregnancy rate (18 pregnancies (38.3%), with 17 (36.2%) ongoing) compared with 64 control women (ten pregnancies (18.5%), nine (16.7%) ongoing). However, there was no significant reduction in the miscarriage rate. Intrauterine infusion of autologous PRP gel during endometrial preparation for FET cycles can improve the EMT, clinical pregnancy rate, and ongoing pregnancy rate in women with thin endometrium.

Intramural Leiomyomas and Fertility: A Systematic Review and Meta-Analysis.

To evaluate fertility outcomes based on size and number of intramural leiomyomas and outcomes after removal. Online searches: MEDLINE, ClinicalTrials.gov , PubMed, Cochrane Library, and PROSPERO Library from 1994 to 2023. A total of 5,143 studies were identified, with inclusion of 13 study groups. Outcomes for size and number of leiomyomas were reported with clinical pregnancy rates and ongoing pregnancy or live-birth rates. In data sets with maximum leiomyoma diameters of less than 6 cm for study inclusion, women with leiomyomas smaller than 3 cm had lower clinical pregnancy rates than women without leiomyomas, with an odds ratio (OR) of 0.53 (95% CI, 0.38-0.76) and, for ongoing pregnancy or live-birth rates, an OR of 0.59 (95% CI, 0.41-0.86). The ORs for clinical pregnancy rates in women with intermediately-sized leiomyomas (those between 3 cm and 6 cm) were lower than in women without leiomyomas, with an OR at 0.43 (95% CI, 0.29-0.63) and, for ongoing pregnancy or live-birth rates, an OR at 0.38 (95% CI, 0.24-0.59). In data sets without exclusion for women with larger-sized leiomyomas, clinical pregnancy rates were lower for those with leiomyomas smaller than 5 cm compared with those without leiomyomas, with an OR of 0.75 (95% CI, 0.58-0.96). Women with leiomyomas larger than 5 cm showed no differences in clinical pregnancy rate compared with women without leiomyomas, with an OR of 0.71 (95% CI, 0.32-1.58). Although women with a single leiomyoma in any location had no differences in outcomes, those with more than one leiomyoma had lower clinical pregnancy rates and ongoing pregnancy or live-birth rates, with an OR of 0.62 (95% CI, 0.44-0.86) and 0.57 (95% CI, 0.36-0.88), respectively. The clinical pregnancy rate for women undergoing myomectomy for intramural leiomyomas was no different than those with intramural leiomyomas in situ, with an OR of 1.10 (95% CI, 0.77-1.59). Even small intramural leiomyomas are associated with lower fertility; removal does not confer benefit. Women with more than one leiomyoma in any location have reduced fertility.

O-027 Efficacy results from the phase II randomized clinical trial: OXO-001 in infertile women undergoing egg donation IVF/ICSI

Abstract Study question Does OXO-001 increase implantation and pregnancy rates in women undergoing egg donation IVF/ICSI and embryo transfer (ET) compared to placebo? Summary answer This proof-of-concept (PoC) prospective randomized and controlled study shows that OXO-001 treatment increases implantation and pregnancy rates in infertile women undergoing IVF/ICSI with studied doses. What is known already OXO-001 is a drug being developed as an innovative treatment to enhance embryo implantation through a direct effect on the endometrium. Preclinical results show an increase in embryo implantation and viability. Moreover, they show that OXO-001 is safe for the mother, the fetuses, and the newborns without any deleterious effect on the development, viability, and implantation potential of OXO-001-exposed embryos. Neither conceptus development nor morphological disturbances have been observed in the deciduas of treated-pregnant mice. Furthermore, clinical trials confirmed that OXO-001 has the necessary wide safety margin and non-complex kinetics, allowing further research on its therapeutic potential in infertility. Study design, size, duration It was a randomized, double-blind, placebo-controlled, and multicenter phase II clinical trial with three parallel arms conducted at 28 European centers (September/2021-January/2023. EudraCT Num:2021-000001-25). A subset of women ≤40 years were analyzed. A total of 173 were randomized in the three study arms (Placebo, 200 and 300mg/day OXO-001). Treatment started one menstrual cycle before the ET cycle and continued until 5 weeks after ET. The results of this communication are focused on the 300mg/day dose. Participants/materials, setting, methods Patients were infertile women (18-40 years; BMI 18-30 kg/m2) eligible for a fresh-single blastocyst (day 5 and ≥3BB) ET resulting from a donor egg. Exclusion criteria include gynecological abnormalities and history of ≥ 2 failed ET, among others. The primary endpoint was ongoing pregnancy rate (OPR). Secondary included biochemical and clinical pregnancy (BPR and CPR), live birth rate (LBR), and safety and tolerability of OXO-001. Main results and the role of chance 111 women were randomized, and 96 performed a single ET (42 Placebo, 54 OXO-001 300mg/day). Higher BPR, CPR, OPR, and LBR per delivery after were observed in the OXO-001 group versus placebo (75.9% vs. 52.4%*, 50.0% vs. 37.5%, 46.3% vs. 35.7%, 42.6% vs. 35.7%, respectively. *p&amp;lt;0.05). The logistic regression analysis showed a statistically significant difference in the BPR for OXO-001 versus placebo (OR 3.03, 95% CI 1.17-7.85; p = 0.022), and a clinically meaningful difference for CPR, OPR, and LBR after a single ET. In safety evaluation, the frequency of treatment-emergent adverse events (TEAEs) assessed as at least possibly related to the study medication were similar between groups (14 for OXO-001 and 10 for placebo). Most TEAEs were mild or moderate in severity. The most common TEAES were headache, nausea and vomiting, gastrointestinal and dizziness. The assigned study medication was well tolerated, and relevant changes in laboratory analyses (hematology and biochemical profile) were not observed. Limitations, reasons for caution This PoC study was designed to define clinically meaningful differences in fertility outcomes and find patient profiles. It was not empowered to find statistical differences in the OPR. An empowered phase III study is needed to confirm the positive results from phase II. Wider implications of the findings his phase II PoC has achieved its objectives showing that OXO-001 increases more than 10% pregnancy rates in infertile women undergoing IVF/ICSI, with a safe and well-tolerated profile. This is a step forward toward the first therapeutic tool to increase embryo implantation and ET success. Trial registration number EudraCT Number: 2021-000001-25

O-149 The Endometriosis Longitudinal Fertility Study (ELFS): Outcomes for women with moderate or severe endometriosis who are trying to conceive

Abstract Study question What are the pregnancy outcomes for women with moderate or severe endometriosis who are trying to conceive? Summary answer Preliminary pregnancy rates in women with moderate/severe endometriosis are 11% for natural conception cycles and 22% for ART cycles. This is consistent with previous literature. What is known already Endometriosis is associated with reduced pregnancy rates in women attempting both spontaneous and assisted conception. Monthly fecundity is approximately half that of women without endometriosis and reduces further with increasing severity of disease. At present, the effect of surgery on the fertility outcomes of women with moderate or severe endometriosis remains unanswered. Treatment decisions are complex, particularly in those without pain symptoms seeking to optimise fertility outcomes. Study design, size, duration ELFS is a prospective multi-site longitudinal cohort study being conducted over 5-years. This interim report summarises data from August 2021-January 2024 in participants &amp;lt;38 years with evidence of in-situ moderate or severe endometriosis desiring fertility immediately or in the future. ELFS prospectively measures and compares monthly clinical pregnancy and live birth rates in women having either surgical or conservative management of endometriosis. This report assesses outcomes for those trying to conceive naturally or with ART. Participants/materials, setting, methods Following consent and baseline questionnaire completion, participants install the purpose-built ELFS App to their mobile phone or use a web-based option to complete cyclical surveys. The timing of surveys is dependent on a learned logic within the App and based on menstrual cycle length and pregnancy status. Participants report attempted conception cycles and any ART treatments undertaken with IVF or intrauterine insemination (IUI). Pregnancy outcomes are recorded as well as surgery during the study period. Main results and the role of chance There are 124 participants enrolled in ELFS, 86 (69%) are in the surgical cohort and 38 (31%) in the conservative cohort. There are 45 participants (36%) who have indicated they are actively trying to conceive during the study and a total of 171 cycles have been recorded from these participants. Of those trying to conceive, 24 (53%) have elected to have surgery during the study period, compared to 23 (29%) who were not trying to conceive. The study has captured 126 cycles with attempted conception. Of these, 42 cycles (33%) utilised ART compared to 84 cycles (67%) of natural conception attempts. Of the ART cycles, 27 (75%) involved IVF with fresh or frozen embryo transfer and there were 9 (15%) IUI cycles. To date, there are 25 reported pregnancies. The pregnancy rate for ART cycles was 22% (8/36) compared to 11% (9/87) in the natural conception cycles. Of those who conceived following surgery, 47% (8/17) of pregnancies were following ART and 53% (9/17) were natural conceptions. There are 2 live births recorded, both from the cohort who had surgery during the study. A total of 5 miscarriages (20%) have been reported, 4 (80%) from the surgical cohort. Limitations, reasons for caution In the absence of data to guide management in this area, clinician scope of practice and concurrent pain symptoms are likely to influence recommendations for ART or surgery in those trying to conceive with moderate or severe endometriosis. Wider implications of the findings This preliminary data is consistent with the current literature showing reduced natural and assisted conception rates in women with moderate or severe endometriosis. Long-term data will be required to determine if fertility and pregnancy outcomes are influenced by surgical management of endometriosis. Trial registration number ACTRN12621000431820 (ANZCTR)

O-202 Novel use of hyaluronan enriched media for improving implantation in intrauterine insemination: a prospective randomised controlled trial (HEMI Trial)

Abstract Study question Does the intrauterine instillation of hyaluronan-enriched media influence the implantation rate and reproductive outcomes in patients undergoing controlled ovarian stimulation and intrauterine insemination? Summary answer The intrauterine instillation of Hyaluronan-enriched media significantly improved the implantation rates and ongoing pregnancy rate in women undergoing controlled ovarian stimulation and intrauterine insemination treatment What is known already Hyaluronan is a macromolecule belonging to the glycosaminoglycans family, secreted by cumulus granulosa cells, and is naturally present in the female reproductive tract. Various mechanisms have been proposed to explain the implantation-enhancing properties of Hyaluronan including increased cell-cell and cell-matrix adhesion, by producing a viscous environment for the integration of embryo in intrauterine fluid and its autocrine and paracrine functions via CD44 receptors. This is probably the first trial studying the effect of hyaluronan-enriched media in intrauterine insemination treatment. The proposed novel intervention is based on the biological plausibility and proven safety of hyaluronan in IVF studies. Study design, size, duration This parallel group Randomised Controlled trial was conducted over 2 years of duration, from 2021 to 2023. A total of 100 couples diagnosed with unexplained infertility planned for controlled ovarian stimulation and intrauterine insemination (COS-IUI) treatment were randomized into the intervention and control arm of the trial. Before the commencement of the study, the trial was registered with the Clinical Trial Registry-India (CTRI), and institutional ethical approval was obtained. Participants/materials, setting, methods 100 couples diagnosed with unexplained infertility attending tertiary-level university hospital were allocated to the intervention and control group using block randomization in 1:1 allocation. In the intervention group, the participants underwent intrauterine instillation of 0.4 ml of hyaluronan enriched media, 4 days following intrauterine insemination treatment. The statistical package SPSS (version 21) was used for analysis and results were considered to be statistically significant if the P-value was &amp;lt;0.05. Main results and the role of chance The mean female age of the study population was 28.12±3.74 years with an average duration of infertility of 3.95 ±2.17 years. The study participants underwent an average of 1.7 IUI cycles in the control group and 1.6 cycles in the intervention group. A cumulative biochemical pregnancy rate of 36.5% and 16.6% was observed amid the the intervention group and control group respectively and the difference was statistically significant with a p-value of 0.039. Similarly, the cumulative ongoing pregnancy rate beyond 20 weeks of gestation was statistically significantly higher among the intervention arm of the trial as compared to the control group (31.7% vs 11.9%, p = 0.035). There was a trend of improved clinical pregnancy rate among the intervention participants, however, this difference did not reach statistical significance (34.1% vs 16.6%, p = 0.067). The miscarriage rate was comparable among both groups. The number needed to treat was estimated to be 5, which in effect meant that 5 women would have to receive intrauterine instillation of hyaluronan enriched media for 1 additional ongoing pregnancy. Limitations, reasons for caution The longer follow-up period would have allowed the reporting of live-birth rate which is undeniably the most meaningful parameter to appraise an intervention. Larger multicentric studies are required to establish the clinical benefit and generalisability of the proposed intervention. Wider implications of the findings The study proposes a potential novel, simple, minimally invasive, and patient-acceptable intervention to increase the success rates of intrauterine insemination. Being the first study on the topic, the study can provide a basis for future large multicentric studies on the topic. Trial registration number Clinical Trial Registry-India (CTRI) number- CTRI/2021/10/037064.

P-626 Progesterone rescue is effective for clinical pregnancy outcome in women presenting low circulating progesterone levels at frozen embryo transfer day

Abstract Study question Is subcutaneous progesterone (prolutex® 25mg daily) addition effective for clinical pregnancy outcome in women presenting low progesterone(P4) levels at frozen embryo transfer(FET) day? Summary answer Subcutaneous progesterone rescue improved ongoing pregnancy rate and clinical pregnancy rate in women with low P4 results at FET day. What is known already FET has been increased, because preimplantation genetic testing for aneuploidies is performed widely, and FET presents a significantly low risk of ovarian hyperstimulation syndrome.In FET, there is no established optimal protocol for preparing endometrium, but hormonal replacement therapy (HRT) is widely used due to its convenient schedule adjustment. HRT protocol induce anovulation, functioning corpus luteum is lacking and exogenous progesterone administration is very important. Therefore, women showing low P4 levels around FET day have lower pregnancy rate. However, there are currently no data on the effectiveness of progesterone rescue. Study design, size, duration Primary outcomes from a randomized cohort retrospective study investigating subcutaneous progesterone (prolutex® 25mg) daily addition for whom had low P4 levels (&amp;lt;12ng/mL) at FET day. The study was conducted at one infertility center in Korea from January 2022 to December 2023 and pregnancy outcomes of FET transfers registered until Oct. 2023,. 194 patients fulfilled the inclusion criteria. Participants/materials, setting, methods One hundred ninety four women divided into two groups based on progesterone levels, with 12ng/ml as the threshold. Under 12ng/mL group were randomized to subgroup with and without addition of subcutaneous progesterone. In total 278 FET cycles, the effect of progesterone rescue on cumulative clinical pregnancy rate (CPR), Ongoing pregnancy rate (OPR) was reported as primary outcomes. Main results and the role of chance In total 278 cycles, there were 137 cycles with adequate serum P4 levels, while 141 cycles presented with low P4 levels in which randomly rescue subcutaneous progesterone administration added from next day of embryo transfer. When comparing the groups, there was no statistical difference in maternal age, BMI, smokers, duration of infertility, type of infertility, indication of in vitro fertilization(IVF), endometrial preparation method. In low P4 group, with and without subcutaneous progesterone addition subgroups included 51 and 90 cycles, retrospectively. CPR were 52.9% versus 35.6% (P = 0.044; chi-squared test) with a statistically significant higher rate of OPR in progesterone rescue group (45.1% versus 28.9%, p = 0.052). When comparing the group with adequate P4 levels and the group with low P4 levels without progesterone rescue, OPR were 18.2% versus 28.9% (p = 0.06, chi-squared test), CPR was significantly higher in low P4 levels group (23.4% versus 35.6%,p=0.046, chi-squared test). Adequate P4 level group had more IVF attempts (4.6 versus 2.2, p &amp;lt; 0.001, chi-squared test). There is tendency to use more luteal phase support medication with repeated attempt (serum P4 concentration on ET day 39.3 ng/mL versus 8.7 ng/mL, p &amp;lt; 0.001, t-test) Limitations, reasons for caution The main limitation of the study was retrospective, and had small sample size. A control group without progesterone rescue in low P4 levels did not receive any intervention. Wider implications of the findings The progesterone rescue for women presenting low P4 on FET day improved clinical outcome and excessively raising progesterone medication may have adverse effects. Therefore rather than using excessive progesterone administration from luteal support start day, progesterone rescue might be effective when low P4 levels presenting at FET day. Trial registration number not applicable

O-151 Endometrial preparation using CONCEIVF algorithm with intrauterine and sub-endometrial endosera administration for enhanced pregnancy rates in women with thin endometrium

Abstract Study question Could personalized regenerative medicine based strategies promote endometrial growth and receptivity in women with refractory thin endometrium resulting in successful implantation and live births? Summary answer Personalized regenerative medicine based strategies remarkably promote endometrial growth and receptivity in women with refractory thin endometrium resulting in successful implantation and live births What is known already Thin endometrium (&amp;lt;7mm) is considered sub-optimal for embryo transfer and associated with reduced pregnancy chances. Regenerative medicine based strategies utilizing stem cells, growth factors alone or in combination for endometrial regeneration have been proposed as futuristic clinical therapies. Data-intensive biomedical technologies in research studies reveals that humans vary widely at genetic, biochemical, physiological, exposure and behavioral levels, especially with respect to disease processes and treatment responsiveness. Hence there is a need to deeply ‘personalize,’ interventional strategies at clinical and dosage level for individual patients. Study design, size, duration In this self- controlled study, 60 women with history of more than 3 failed IVF cycles due to persistent refractory thin endometrium (&amp;lt;7mm) were enrolled between July 21-December 23. 42 women were treated with intrauterine administration of Endosera and 18 patients were treated with sub-endometrial administration of Endosera as suggested by CONCEIVF - Proprietary Algorithm from Seragen.. Endosera is Autologous platelet derived implantation friendly anti-inflammatory cytokines and concentrated growth factors and progenitor cells. Participants/materials, setting, methods CONCEIVF-Algorithm classifies patients (High, Moderate, Poor responders) based on age, BMI, clinical history, guiding standardized dosage routines for proliferative, secretory, implantation phases including CD 33/CD34 cells minimal threshold, are specified. Intrauterine Endosera administration, 2 or 3 times from menstrual cycle day 5 during FET, precedes embryo transfer. Sub-endometrial administration involves Endosera with endothelial progenitor cell support on cycle days 5-7, followed by embryo transfer two days after the final Endosera infusion in the subsequent cycle. Main results and the role of chance Clinical pregnancy rate was 77%(46/60), no pregnancy in 10 patients accounting for 17%. 50% (30/60) delivered healthy babies and 17%(10/60) of uneventful pregnancies are progressing. 3 patients (5%) had miscarriage between 6-8 weeks. Improvement in endometrium thickness (EMT) was 90% with mean difference of 1.9mm improvement in 54 patients. No adverse effects reported. 33 patients out of 42 conceived and 6 out of 42 patients did not conceive and 3 out of 42 patients are yet to undergo embryo transfer in the intra-uterine group. 13 patients out of 18 conceived and 4 out of 18 patients did not conceive and 1 out of 18 patient is yet to undergo embryo transfer in the sub-endometrial group. Live birth rate and on-going pregnancies are indicators of overall endometrial quality (thickness and receptivity) improvement and validates that personalization helps to achieve maximum success rate. 15 out of 60 patients who were referred to surrogacy have conceived. In women with a history of cycle cancellations due to thin endometrium, CONCEIVF algorithm recommended personalized Endosera dosages resulted in improved endometrial thickness, clinical pregnancy and live birth. Personalization holds the key for precision because now two patients are alike! Limitations, reasons for caution This prospective self-control study, contains small sample size and lacks randomized controlgroup. Our results are encouraging but large cohort of patients is needed to establish efficacy. of protocols and positive patient predictors score to strengthen Conceivf personalized recommendations. Wider implications of the findings Despite global rise in FET for diverse indications, ongoing efforts to find the optimal endometrial preparation protocol persist. Our personalized approach achieved cumulative 74% pregnancy rate (40/54 ETs done), inspiring planned randomized trials to validate results and help women with resistant thin endometrium to conceive without surrogacy. Trial registration number Not applicable

P-553 Embryo collection improves clinical pregnancy outcomes in next-generation sequencing(NGS)-based preimplantation genetic testing for aneuploidy (PGT-A) euploid embryo transfers

Abstract Study question Is there still a significant impact of embryo-related characteristics on pregnancy rates in NGS based PGT-A euploid embryo transfers for advanced-age patients? Summary answer In single frozen euploid embryo transfers, priority of embryo transfer and grade significantly influence clinical pregnancy rates in women over 35 years old with PGT-A. What is known already It is widely recognized that better embryo grades and a shorter duration of blastulation are associated with favorable reproductive outcomes. Recent meta-analyses have affirmed these findings even in the context of transfer with euploid embryos. However, the impact of prioritizing the highest-ranked embryo among multiple vitrified euploid embryos on pregnancy rates remains unclear. The lack of research in this area implies a gap in understanding whether selecting embryos for transfer among multiple viable euploid embryos could enhance reproductive success. Study design, size, duration Throughout the year 2022, a retrospective review was conducted on 428 cycles of single frozen-thawed euploid embryo transfers performed at a single institution, targeting patients aged 35 and older. The study aimed to explore potential differences in clinical pregnancy rates based on embryo grade, embryo freezing date, and embryo selection priority. Participants/materials, setting, methods Women ≥ 35 years old with single frozen euploid blastocyst transfer cycles was categorized into three groups: (a) with one blastocyst (1/1), (b) with ≥ two blastocysts having the top-priority(½ or higher), and (c) lower-priority blastocysts (lower than ½) to examine potential differences in clinical pregnancy rates among groups based on embryo characteristics, including Gardner grading and day of embryo freezing. Results highlight the impact of both selection criteria and freezing conditions on pregnancy outcomes. Main results and the role of chance This study analyzed a total of 428 frozen embryo transfer (FET) cycles. In the context of frozen-thawed single embryo transfer, the clinical pregnancy rate was 52.2% (128/245) when only one euploid embryo was frozen and subsequently thawed for transfer (a). For cases where two or more euploid embryos were frozen, and embryos with a higher priority (½ or higher) were selected for transfer (b), the clinical pregnancy rate significantly increased to 71.3% (62/87). Conversely, when embryos with a lower priority (lower than ½ in order) were chosen for transfer (c), the clinical pregnancy rate was lower at 38.5% (15/38), indicating a statistically significant difference between the groups (p = 0.001). Categorizing embryos based on Gardner grading, “good” embryos (&amp;gt;3BB) demonstrated a clinical pregnancy rate of 66.8% (141/211), while embryos with lower quality (3BB or below) showed a significantly lower clinical pregnancy rate of 40.6% (88/217) (p &amp;lt; 0.001). The analysis of clinical pregnancy rates based on the embryo freezing day revealed significant differences among embryos freezing on 5 days (71.9%, 133/185), 6 days (39.9%, 71/178), 7 days (25%, 2/8), and thawing PGT-A embryos (38.2%, 21/55) (P &amp;lt; 0.001). Limitations, reasons for caution One limitation of this study is its retrospective nature, and the potential confounding effect of the close association between embryo selection and embryo grading. Further analysis will be conducted to confirm correlations and address this potential confounding effect. Wider implications of the findings In single euploid frozen embryo transfers, selecting the highest-quality embryo through careful embryo selection remains relevant. Morphological indicators of embryos significantly impact early pregnancy outcomes, highlighting the continued importance of strategic embryo accumulation for enhanced procedural success. Trial registration number not applicable

P-706 The pregnancy rates in a large cohort of patients with thin endometrium when stratified according to estradiol levels on the day of triggering

Abstract Study question Is there any difference in ongoing pregnancy rate in women with thin endometrium (&amp;lt;8 mm) when scrutinized based on estradiol levels on triggering day? Summary answer Either with a low, moderate, or high estradiol level on the day of triggering, ongoing pregnancy rates do not change in patients with thin endometrium. What is known already Endometrial thickness has been argued to be one of the proxy determinants of endometrial receptivity. In that context, although the optimal thickness has been widely stated to be between 8-14 mm, the negative effect of thin endometrium on pregnancy outcome is still controversial in in-vitro-fertilization (IVF) cycles. Nevertheless, particularly lack of large sample size of women with thin endometrium among the available literature, is the leading factors that avoids to solid conclusion.Furthermore, it might be hypothesized that patients with thin endometrium and accompanying low estradiol might be distinct from women with thin endometrium despite relatively high estradiol level. Study design, size, duration A retrospective cohort study was designed among patients that has undergone in-vitro fertilization (IVF) treatment between January-2018 and June-2023 in Bahceci Health Group. Only patients having an endometrial thickness &amp;lt;8 mm on the day of triggering were recruited. Other inclusion criteria was having at least one blastocyst to be transferred. All frozen-thawed embryo transfer cycles were excluded. Female age and body mass index were not considered as an exclusion criterion. Participants/materials, setting, methods During the study period, a total of 3076 IVF cycles with fresh ET were employed. Of them, 814 had an endometrial thickness of &amp;lt; 8 mm on the day of triggering. Among 814 IVF cycles, 25th, 50th and 75th quartiles of estradiol levels on the day of triggering referred to 322.8, 755.7 and 1310.5 pg/ml, respectively. The number of IVF-ET cycles in the 1st, 2nd, 3th and 4th quartiles were 203, 204, 204 and 203. Main results and the role of chance The mean (SD) age of women recruited in the final analyses was 36.5 (5.5) years and endometrial thickness was 7.2 (0.8) mm. The pregnancy rates per ET with regard to 1st, 2nd, 3th and 4th quartiles were 37.6%, 33.0%, 37.3% and 44.3%, respectively without any statistical significance (p = 0.134). However, the respective ongoing pregnancy rates were 26.1%, 18.1%, 22.1%, 31.0 % and the highest quartile had a statistically superior ongoing pregnancy rates than the second (p = 0.003) and third quartiles (p = 0.022). When binary logistic regression analysis was performed by inserting the female age, body-mass index, duration of infertility and quartiles of estradiol levels on the day of triggering, only female age remained as an independent factor for the prediction of an ongoing pregnancy (RR: 0.92 CI95%: 0.87 to 0.98, p = 0.008). Utilization of estradiol level as a continuous variable in the same model also failed to present the independent validity of it to predict an ongoing pregnancy. Notably, the lowest thickness of a positive pregnancy resulting with an ongoing pregnancy was 4.7 mm. Limitations, reasons for caution The inherent risks cannot be excluded due to the retrospective nature of the current study, which had been efforted to overcome with regression analysis. Wider implications of the findings The current study includes one of the largest numbers of experience particularly with thin endometrium on the day of triggering. However, having a thin endometrium despite low or relatively high estradiol level does yield any prediction for the pregnancy outcome. Trial registration number Not Applicable

Does Gonadotropin-Releasing Hormone Agonist Administration Before Assisted Reproduction Techniques Improve Pregnancy Rates in Women With Endometriosis?

Axial downregulation with a 3- to 6-month administration of gonadotropin-releasing hormone agonists (GnRH-a) prior to assisted reproduction techniques has been proposed in order to improve clinical pregnancy rates in women with endometriosis. Although reduced inflammation, improved oocyte quality, and restored endometrial receptivity have been postulated, further investigation of their actual benefit and mechanism of action is considered essential. In that direction, well-designed clinical trials regarding the role of GnRH-a in IVF are necessary. The purpose of this review is to clarify whether GnRH-a administration prior to IVF-FET procedures improves pregnancy rates in women with endometriosis. A literature review was conducted in MEDLINE (PubMed), Cochrane, and Google Scholar and concluded on September 10, 2022. Two Cochrane meta-analyses and 16 selected studies present various interesting data of assisted reproduction technique procedures on patients with endometriosis-related infertility with or without depot GnRH-a pretreatment. The regimen may have a positive clinical effect on cases of severe endometriosis (American Society for Reproductive Medicine stages III-IV), but their use is not routinely recommended in order to improve pregnancy rates. Endometriosis and infertility are closely related through various pathogenetic mechanisms. Endometriosis has been traditionally considered to negatively affect fundamental aspects of the in vitro fertilization-frozen embryo transfer procedure. Numerous interventions, both medical and surgical, have been proposed in order to improve IVF success rates, and the optimal management of these cases poses an ever pressing challenge.

Androgens (dehydroepiandrosterone or testosterone) for women undergoing assisted reproduction.

Practitioners in the field of assisted reproductive technology (ART) continually seek alternative or adjunct treatments to improve ART outcomes. This Cochrane review investigates the adjunct use of synthetic versions of two naturally produced hormones, dehydroepiandrosterone (DHEA) and testosterone (T), in assisted reproduction. Steroid hormones are proposed to increase conception rates by positively affecting follicular response to gonadotrophin stimulation. This may lead to a greater oocyte yield and, subsequently, an increased chance of pregnancy. To assess the effectiveness and safety of DHEA and T as pre- or co-treatments in infertile women undergoing assisted reproduction. We searched the following electronic databases up to 8 January 2024: the Gynaecology and Fertility Group (CGF) Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, and trial registries for ongoing trials. We also searched citation indexes, Web of Science, PubMed, and OpenGrey. We searched the reference lists of relevant studies and contacted experts in the field for any additional trials. There were no language restrictions. Randomised controlled trials (RCTs) comparing DHEA or T as an adjunct treatment to any other active intervention, placebo, or no treatment in women undergoing assisted reproduction. Two review authors independently selected studies, extracted relevant data, and assessed risk of bias. We pooled data from studies using fixed-effect models. We calculated odds ratios (ORs) for each dichotomous outcome. Analyses were stratified by type of treatment. We assessed the certainty of evidence for the main findings using GRADE methods. We included 29 RCTs. There were 1599 women in the intervention group and 1469 in the control group. Apart from three trials, the trial participants were women identified as 'poor responders' to standard in vitro fertilisation (IVF) protocols. The included trials compared either T or DHEA treatment with placebo or no treatment. Pre-treatment with DHEA versus placebo/no treatment: DHEA likely results in little to no difference in live birth/ongoing pregnancy rates (OR 1.30, 95% confidence interval (CI) 0.95 to 1.76; I² = 16%, 9 RCTs, N = 1433, moderate certainty evidence). This suggests that in women with a 12% chance of live birth/ongoing pregnancy with placebo or no treatment, the live birth/ongoing pregnancy rate in women using DHEA will be between 12% and 20%. DHEA likely does not decrease miscarriage rates (OR 0.85, 95% CI 0.53 to 1.37; I² = 0%, 10 RCTs, N =1601, moderate certainty evidence). DHEA likely results in little to no difference in clinical pregnancy rates (OR 1.18, 95% CI 0.93 to 1.49; I² = 0%, 13 RCTs, N = 1886, moderate certainty evidence). This suggests that in women with a 17% chance of clinical pregnancy with placebo or no treatment, the clinical pregnancy rate in women using DHEA will be between 16% and 24%. We are very uncertain about the effect of DHEA on multiple pregnancy (OR 3.05, 95% CI 0.47 to 19.66; 7 RCTs, N = 463, very low certainty evidence). Pre-treatment with T versus placebo/no treatment: T likely improves live birth rates (OR 2.53, 95% CI 1.61 to 3.99; I² = 0%, 8 RCTs, N = 716, moderate certainty evidence). This suggests that in women with a 10% chance of live birth with placebo or no treatment, the live birth rate in women using T will be between 15% and 30%. T likely does not decrease miscarriage rates (OR 1.63, 95% CI 0.76 to 3.51; I² = 0%, 9 RCTs, N = 755, moderate certainty evidence). T likely increases clinical pregnancy rates (OR 2.17, 95% CI 1.54 to 3.06; I² = 0%, 13 RCTs, N = 1152, moderate certainty evidence). This suggests that in women with a 12% chance of clinical pregnancy with placebo or no treatment, the clinical pregnancy rate in women using T will be between 17% and 29%. We are very uncertain about the effect of T on multiple pregnancy (OR 2.56, 95% CI 0.59 to 11.20; 5 RCTs, N = 449, very low certainty evidence). We are uncertain about the effect of T versus oestradiol or T versus oestradiol + oral contraceptive pills. The certainty of the evidence was moderate to very low, the main limitations being lack of blinding in the included trials, inadequate reporting of study methods, and low event and sample sizes in the trials. Data on adverse events were sparse; any reported events were minor. Pre-treatment with T likely improves, and pre-treatment with DHEA likely results in little to no difference, in live birth and clinical pregnancy rates in women undergoing IVF who have been identified as poor responders. DHEA and T probably do not decrease miscarriage rates in women under IVF treatment. The effects of DHEA and T on multiple pregnancy are uncertain. Data regarding adverse events were very limited; any reported events were minor. Research is needed to identify the optimal duration of treatment with T. Future studies should include data collection on adverse events and multiple pregnancy.

Association of ambient air pollutant mixtures with IVF/ICSI-ET clinical pregnancy rates during critical exposure periods

Abstract STUDY QUESTION Does exposure to a mixture of ambient air pollutants during specific exposure periods influence clinical pregnancy rates in women undergoing IVF/ICSI-embryo transfer (ET) cycles? SUMMARY ANSWER The specific exposure period from ET to the serum hCG test was identified as a critical exposure window as exposure to sulfur dioxide (SO2) or a combination of air pollutants was associated with a decreased likelihood of clinical pregnancy. WHAT IS KNOWN ALREADY Exposure to a single pollutant may impact pregnancy outcomes in women undergoing ART. However, in daily life, individuals often encounter mixed pollution, and limited research exists on the effects of mixed air pollutants and the specific exposure periods. STUDY DESIGN, SIZE, DURATION This retrospective cohort study involved infertile patients who underwent their initial IVF/ICSI-ET cycle at an assisted reproduction center between January 2020 and January 2023. Exclusions were applied for patients meeting specific criteria, such as no fresh ET, incomplete clinical and address information, residency outside the 17 cities in the Sichuan Basin, age over 45 years, use of donor semen, thin endometrium (&amp;lt;8 mm) and infertility factors unrelated to tubal or ovulation issues. In total, 5208 individuals were included in the study. PARTICIPANTS/MATERIALS, SETTING, METHODS Daily average levels of six air pollutants (fine particulate matter (PM2.5), inhalable particulate matter (PM10), SO2, nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3)) were acquired from air quality monitoring stations. The cumulative average levels of various pollutants were determined using the inverse distance weighting (IDW) method across four distinct exposure periods (Period 1: 90 days before oocyte retrieval; Period 2: oocyte retrieval to ET; Period 3: ET to serum hCG test; Period 4: 90 days before oocyte retrieval to serum hCG test). Single-pollutant logistic regression, two-pollutant logistic regression, Quantile g-computation (QG-C) regression, and Bayesian kernel machine regression (BKMR) were employed to evaluate the influence of pollutants on clinical pregnancy rates. Stratified analyses were executed to discern potentially vulnerable populations. MAIN RESULTS AND THE ROLE OF CHANCE The clinical pregnancy rate for participants during the study period was 54.53%. Single-pollutant logistic models indicated that for PM2.5 during specific exposure Period 1 (adjusted odds ratio [aOR] = 0.83, 95% CI: 0.70–0.99) and specific exposure Period 4 (aOR = 0.83, 95% CI: 0.69–0.98), and SO2 in specific exposure Period 3 (aOR = 0.92, 95% CI: 0.86–0.99), each interquartile range (IQR) increment exhibited an association with a decreased probability of clinical pregnancy. Consistent results were observed with dual air pollution models. In the multi-pollution analysis, QG-C indicated a 12% reduction in clinical pregnancy rates per IQR increment of mixed pollutants during specific exposure Period 3 (aOR = 0.89, 95% CI: 0.79–0.99). Among these pollutants, SO2 (33.40%) and NO2 (33.40%) contributed the most to the negative effects. The results from BKMR and QG-C were consistent. Stratified analysis revealed increased susceptibility to ambient air pollution among individuals who underwent transfer of two embryos, those with BMI ≥ 24 kg/m2 and those under 35 years old. LIMITATIONS, REASONS FOR CAUTION Caution was advised in interpreting the results due to the retrospective nature of the study, which was prone to selection bias from non-random sampling. Smoking and alcohol, known confounding factors in IVF/ICSI-ET, were not accounted for. Only successful cycles that reached the hCG test were included, excluding a few patients who did not reach the ET stage. While IDW was used to estimate pollutant concentrations at residential addresses, data on participants’ work locations and activity patterns were not collected, potentially affecting the accuracy of exposure prediction. WIDER IMPLICATIONS OF THE FINDINGS Exposure to a mixture of pollutants, spanning from ET to the serum hCG test (Period 3), appeared to be correlated with a diminished probability of achieving clinical pregnancy. This association suggested a potential impact of mixed pollutants on the interaction between embryos and the endometrium, as well as embryo implantation during this critical stage, potentially contributing to clinical pregnancy failure. This underscored the importance of providing women undergoing ART with comprehensive information to comprehend the potential environmental influences and motivating them to adopt suitable protective measures when feasible, thereby mitigating potential adverse effects of contaminants on reproductive health. STUDY FUNDING/COMPETING INTEREST(S) This work received support from the National Key Research and Development Program of China (No. 2023YFC2705900), the National Natural Science Foundation of China (Nos. 82171664, 81971391, 82171668), the Natural Science Foundation of Chongqing Municipality of China (Nos. CSTB2022NSCQ-LZX0062, CSTB2023TIAD-KPX0052) and the Foundation of State Key Laboratory of Ultrasound in Medicine and Engineering (No. 2021KFKT013). The authors report no conflicts of interest. TRIAL REGISTRATION NUMBER N/A.