Embryo Transfer In Natural Cycle Research Articles

Clinical outcomes of frozen-thawed embryo transfer in natural cycles with luteinized unruptured follicles

ObjectiveTo assess the effect of luteinized unruptured follicles (LUF) on frozen–thawed embryo transfer cycles performed in natural cycles (FET-NC). MethodsRetrospective cohort study, held in a university hospital with 3415 cycles for frozen-thawed embryo transfer, performed between June 2019 and September 2022. Using propensity score matching, 242 patients with a diagnosis of LUF (LUF group) were matched with 484 ovulated patients (ovulation group). Stratified by the type of embryo transferred, the LUF group included 168 blastocyst transfer patients (blastocyst group) and 74 cleavage-stage embryo transfer patients (cleavage-embryo group). The ovulation group included 324 patients with blastocyst transfer (blastocyst group) and 160 patients with transferred cleavage-stage embryos. Clinical pregnancy rate was retrospectively analyzed between the LUF and ovulation groups, as well as between each subgroup. ResultsAfter using propensity score matching, the general characteristics of the LUF and ovulation groups were similar. The implantation and clinical pregnancy rates in the LUF group were not significantly different from those in the ovulation group (44.98 % vs. 45.29 %, p = 0.93; 53.72 % vs. 52.48 %, p = 0.75). The implantation and pregnancy rates of transferred cleavage-stage embryos in the LUF group were also not significantly different from those in the ovulation group (32.39 % vs. 36.40 %, p = 0.42; 47.30 % vs. 47.50 %, p = 0.98). The implantation and pregnancy rates of transferred blastocysts in the LUF group were also not significantly different from those in the ovulation group (53.11 % vs. 52.03 %, p = 0.82; 56.55 % vs. 54.94 %, p = 0.73). There was also no significant difference in the miscarriage rate between the groups. ConclusionIn the natural cycle, LUF does not affect the clinical pregnancy outcomes of FET. If adequate luteal support is given, the clinical pregnancy outcomes were similar between the LUF group and ovulation group.

P-614 Endometrial preparation: effect of estrogen levels before the embryo transfer on the live birth rate from 14825 freezing-all cycles

Abstract Study question Is there a difference in live birth rate during discrepant estrogen levels before the embryo transfer following either hormone replacement therapy (HRT) or natural cycle(NC)? Summary answer The higher estrogen level on the day before embryo transfer may reduce the live birth rate in either HRT or NC. What is known already The endometrial preparation of frozen embryo transfer cycle is to synchronize of endometrium and embryo under the condition of exogenous estrogen and progesterone drugs in HRT or follicle monitoring in NC. Estrogen is crucial and different estrogen levels could imply variations on endometrial preparation. Information on the effect of discrepant estrogen levels before the embryo transfer on reproductive outcomes of women undergoing freezing-all cycles is scarce. Study design, size, duration Retrospective cohort study including 14825 first frozen embryo transfers following IVF/ICSI undergoing freezing-all cycles from January 2016 to December 2020. A total of 12305 (83.0%) patients received NC while 2520 (17.0%) received HRT. Participants/materials, setting, methods Effect of estrogen levels on live birth rates, stratifified by deciles and ROC to determine the cutoff values for estrogen level on the day before embryo transfer.Multivariable logistic regression analysis was performed to adjust for confounders. Main results and the role of chance The live birth rate was 44.7% and 52.4% in HRT and NC respectively. The live birth rate of HRT began to decline when the estrogen level was P60 in the deciles which the cut-off values of ROC was closed with the estrogen level was 891.6 pg/ml. The lower level of estrogen on the day before embryo transfer in HRT corresponds to a higher live birth rate（51.4% vs 32.9%）.The cut-off values of ROC in NC was statistically different with the estrogen level was 194.4 pg/ml. The lower level of estrogen on the day before embryo transfer in NC corresponds to a higher live rate（53.0% vs 48.6%）.After adjusting the possible confounding factors by multivariate logistic regression, it was found that the estrogen level on the day before embryo transfer in HRT and NC was the independent influencing factor of live birth rate with the OR of 0.57 (0.47,0.68) and 0.82 (0.74,0.90), respectively. Limitations, reasons for caution The greatest limitation of this study is its retrospective study. On the other hand, this study was performed using non-PGT cycle, although this is unlikely to affect the results,we cannot exclude the possibility that euploid embryo responds differently to endometrial state in comparison to aneuploid embryo. Wider implications of the findings In freezing-all cycles, the higher estrogen level on the day before embryo transfer may reduce the live birth rate in either HRT or NC. Clinicians should pay attention to the control of estrogen level in luteal phase. Trial registration number Nona

Are systemic progesterone levels in true natural cycle euploid frozen embryo transfers with luteal phase support predictive for ongoing pregnancy rates?

Are serum progesterone (P4) levels on the embryo transfer (ET) day predictive of ongoing pregnancy (OP) following a single euploid blastocyst transfer in a natural cycle (NC) when luteal phase support is routinely given? In single euploid frozen ETs in NC, P4 levels on ET day are not predictive for OP, when luteal phase support (LPS) is routinely added after the ET. In an NC frozen embryo transfer (FET), P4 produced by the corpus luteum initiates secretory transformation of the endometrium and maintains pregnancy after implantation. There are ongoing controversies on the existence of a P4 cutoff level on the ET day, being predictive for the chance of OP as well as of the possible role of additional LPS after ET. Previous studies in NC FET cycles, evaluating and identifying P4 cutoff levels did not exclude embryo aneuploidy as a possible reason for failure. This retrospective study analyzed single, euploid FET in NC, conducted in a tertiary referral IVF centre between September 2019 and June 2022, for which measurement of P4 on the day of ET and the treatment outcomes were available. Patients were only included once into the analysis. Outcome was defined as OP (ongoing clinical pregnancy with heartbeat, >12 weeks) or no-OP (not pregnant, biochemical pregnancy, early miscarriage). Patients with an ovulatory cycle and a single euploid blastocyst in an NC FET cycle were included. Cycles were monitored by ultrasound and repeated measurement of serum LH, estradiol, and P4. LH surge was identified when a rise of 180% above the previous level occurred and P4 levels of ≥1.0 ng/ml were regarded as confirmation of ovulation. The ET was scheduled on the fifth day after P4 rise and vaginal micronized P4 was started on the day of ET after P4 measurement. Of 266 patients included, 159 (59.8%) patients had an OP. There was no significant difference between the OP- and no-OP-groups for age, BMI, and day of embryo biopsy/cryopreservation (Day 5 versus Day 6). Furthermore, P4 levels were not different between the groups of patients with OP (P4: 14.8 ng/ml (IQR: 12.0-18.5 ng/ml)) versus no-OP (P4: 16.0 ng/ml (IQR: 11.6-18.9 ng/ml)) (P = 0.483), and no differences between both groups, when P4 levels were stratified into categories of P4 levels of >5 to ≤10, >10 to ≤15, >15 to ≤20, and >20 ng/ml (P = 0.341). However, both groups were significantly different for the embryo quality (EQ), defined by inner cell mass/trophectoderm, as well as when stratified into three EQ groups (good, fair, and poor) (P = 0.001 and 0.002, respectively). Stratified EQ groups remained the only significant parameter influencing OP in the uni- and multivariate analyses (P = 0.002 and P = 0.004, respectively), including age, BMI, and P4 levels (each in categories) and embryo cryopreservation day. Receiver operator characteristic curve for the prediction of an OP revealed an AUC of 0.648 when age, BMI and EQ groups were included into the model. The inclusion of P4 measurement on ET day into the model did not add any benefit for OP prediction (AUC = 0.665). The retrospective design is a limitation. Monitoring serum P4 levels can be abandoned in NC FET cycles with routine LPS as they do not seem to be predictive of live birth. No external funding was used for this study. The authors state that they do not have any conflicts of interest. N/A.

Progesterone supplementation in natural cycles improves live birth rates after embryo transfer of frozen-thawed embryos-a randomized controlled trial.

STUDY QUESTIONDoes supplementation with vaginal tablets of progesterone after frozen-thawed embryo transfer in natural cycles improve the live birth rate?SUMMARY ANSWERSupplementation with vaginal tablets of progesterone after frozen-thawed embryo transfer in natural cycles significantly improves the number of live births.WHAT IS KNOWN ALREADYProgesterone supplementation during luteal phase and early pregnancy may improve the number of live births after frozen-thawed embryo transfer. However, due to the limited number of previous studies, being mainly retrospective, evidence is still limited.STUDY DESIGN, SIZE, DURATIONThis is a prospective randomized controlled trial, performed at two university clinics. In total, 500 subjects were randomized with a 1:1 allocation into two groups, during the period February 2013 to March 2018. Randomization was performed after a frozen embryo transfer in a natural cycle by use of opaque sealed envelopes. The primary outcome was live birth rate; secondary outcomes were pregnancy, biochemical pregnancy, clinical pregnancy and miscarriage rate, and if there was a possible association between the serum progesterone concentration on the day of embryo transfer and live birth rate.PARTICIPANTS/MATERIALS, SETTING, METHODSWomen, receiving embryo transfer in natural cycles participated in the study. The embryos were frozen on Day 2, 3, 5 or 6. In total, 672 women having regular menstrual cycles were invited to participate in the study; of those, 500 agreed to participate and 488 were finally included in the study. Half of the study subjects received progesterone supplementation with progesterone vaginal tablets, 100 mg twice daily, starting from the day of embryo transfer. The other half of the subjects were not given any treatment. Blood samples for serum progesterone measurements were collected from all subjects on the day of embryo transfer.MAIN RESULTS AND THE ROLE OF CHANCEThere were no differences in background characteristics between the study groups. In the progesterone supplemented group, 83 of 243 patients (34.2%) had a live birth, compared to 59 of 245 patients (24.1%) in the control group (odds ratio 1.635, 95% CI 1.102–2.428, P = 0.017*). The number of pregnancies was 104 of 243 (42.8%) and 83 of 245 (33.9%), respectively (odds ratio 1.465, 95% CI 1.012–2.108, P = 0.049*) and the number of clinical pregnancies was 91 of 243 (37.4%) and 70 of 245 (28.6%), respectively (odds ratio 1.497, 95% CI 1.024–2.188, P = 0.043*). There were no significant differences in biochemical pregnancy rate or miscarriage rate. There was no correlation between outcome and serum progesterone concentration.LIMITATIONS, REASONS FOR CAUTIONThe study was not blinded because placebo tablets were not available. Supplementation started on embryo transfer day, regardless of the age of the embryos, which resulted in a shorter supplementation time for Day 5/6 embryos compared to Day 2/3 embryos.WIDER IMPLICATIONS OF THE FINDINGSSupplementation with progesterone in natural cycles improved the number of live births after frozen-thawed embryo transfer and should therefore be considered for introduction in clinical routine.STUDY FUNDING/COMPETING INTEREST(S)The study was funded by Uppsala University, the Uppsala-Family Planning Foundation, and Ferring Pharmaceuticals AB, Malmö, Sweden. The authors have no personal conflicting interests to declare.TRIAL REGISTRATION NUMBERNL4152.TRIAL REGISTRATION DATE5 December 2013.DATE OF FIRST PATIENT’S ENROLMENT18 February 2013.

Luteal phase support in fresh and frozen embryo transfers.

ContextLuteal phase support (LPS) has become an essential component of IVF protocols following both fresh and frozen embryo transfers, yet there is still controversy with regards to the optimal protocol of LPS to enhance treatment outcome.Search strategyA search via PubMed for all the selected topics was limited to publications from the past 10 years and to English language. We subsequently searched the reference lists of retrieved articles. Where available, RCTs were chosen over non-randomized studies. Here we provide an updated review of the current literature on various issues relating to LPS, in both fresh and frozen embryo transfers. The timing of LPS initiation as well as the route of administration and dosing are discussed for both fresh and frozen transfers. A separate discussion for frozen thawed embryo transfer in natural cycles and non-ovulatory cycles is presented.ConclusionsWe present data that supports the use of Progesterone LPS in fresh and frozen embryo transfers. No benefits were found to the addition of hCG or estradiol to progesterone LPS in fresh transfers, however GnRH agonist may have a role. IM Progesterone was not advantageous over vaginal progesterone in fresh transfers but was superior in frozen transfers. The timing of LPS introduction, the interval to embryo transfer, as well as the serum concentration of progesterone, have significant effects on the success of the treatment.

P-669 The impact of luteal phase support on pregnancy outcomes in relation to serum progesterone levels on the day of frozen embryo transfer in natural cycles

Abstract Study question Is luteal phase support (LPS) beneficial in low and normal serum progesterone (P) levels the day of frozen embryo transfer (FET) in natural cycles (NC)? Summary answer LPS in case of low serum P on the day of NC-FET results in similar pregnancy rates as compared to patients with normal P levels. What is known already The use of FET cycles has increased exponentially in recent years. Endometrial preparation in FET cycles can be achieved either in a natural cycle, a stimulated cycle or in an artificial cycle (AC). There is increasing evidence that proper serum P levels around the time of FET are important in AC and NC. Recent studies in AC have shown that enhanced progesterone supplementation in case of low serum P levels could reduce early pregnancy loss rates and normalize live birth rates. Whether this rescue strategy could also be beneficial in NC-FET has not been investigated in detail. Study design, size, duration A retrospective study was conducted at a tertiary university-based referral hospital encompassing 459 unique patients who had a NC-FET with or without hCG trigger from November 2020 onwards. Only patients who had an in-house validated serum P measurement (Cobas 6000®,Roche) on the day of FET were included. Blastocyst transfer was performed 6 days after a spontaneous luteinizing hormone (LH) peak or 7 days after hCG administration. Ongoing pregnancy rate (OPR) was the primary outcome. Participants/materials, setting, methods Outcomes were compared in patients with low serum P (<10ng/dl) levels, who received LPS from the day of FET onwards (group 1) and patients with normal serum P (≥10ng/dl) levels (group 2). Group 2 was subdivided into patients who did not received LPS (group 2a) and patients who did (group 2b), as by practitioner’s choice. Multivariable regression analysis was performed adjusting for age, BMI, endometrial thickness, rank of FET, embryo quality and indication for treatment. Main results and the role of chance Mean ages were 31.8 years (group 1) and 33.3 years (group 2, p = 0.004). BMI was significantly lower in group 2 (23.7 kg/m2) compared to group 1 (26.7 kg/m2, p < 0.001). Indication for treatment, menstrual cycle length, anti-Mullerian hormone (AMH) levels and parity were comparable between both groups. An hCG ovulation trigger was administered in 26.0% of the cycles in group 1 and 20.4% in group 2 (p = 0.28). Endometrial thickness was equal in both groups (8.3mm, p = 0.84). In group 1, 40.3% of the patients had a transfer of a top quality embryo as compared to 46.3% in group 2 (p = 0.33). Positive hCG rate (54.6%, 64.0% and 65.0% for group 1, 2a and 2b respectively, p = 0.26) and miscarriage rate per positive hCG (2.4%, 9.2% and 6.7% for group 1,2a and 2b respectively, p = 0.37) were comparable between groups. OPR per started cycle was similar between groups (46.8%, 55.4% and 55.6% for group 1, 2a and 2b respectively, p = 0.37). Multivariable logistic regression analysis showed no relationship between OPR and the three different groups (p = 0.13). A significant association was observed between OPR and patient age at embryo cryopreservation. Limitations, reasons for caution Although only patients were included who had serum P levels on the day of FET measured by a standardized in-house assay, the results of the study are limited by the retrospective nature and its associated bias. Confirmation of the results should be obtained in prospective studies. Wider implications of the findings Luteal phase deficiency was observed in only 16.8% of patients in our study population. Administration of LPS in patients with low serum P levels on the day of FET could rescue pregnancy outcomes. However, starting LPS when serum P levels are normal appears to have no added value. Trial registration number not applicable

Follicular phase length has no influence on frozen-thawed embryo transfers in natural cycles

BackgroundWhether menstrual variability in women with regular and ovulatory cycle could affect embryo implantation remains controversial, with conflicting evidences presented in the literature. Thus, in this study, we evaluated the impact of prolonged follicular phase length (FPL) on the clinical pregnancy rate (CPR) after frozen–thawed embryo transfer (FET) in true natural cycles (NC).MethodsThis retrospective cohort study utilized data from a large university-affiliated reproductive medicine center. Women undergoing true NC-FET were grouped as per their FPL type: Prolonged FPL (n = 127) and Normal FPL (n = 737). The primary study outcome was CPR in these 2 groups.ResultsThe FPL in the current cycle was significantly longer in the Prolonged FPL group (23.0 ± 2.4) than in the Normal FPL group (16.0 ± 2.2; p < 0.001). The crude CPR was significantly higher in the Prolonged FPL group (61.4%) than in the Normal FPL group (51.7%; p = 0.043). After adjusting for the results of potential confounders including the age, BMI, percent of optimal embryos transferred, and endometrial thickness, the difference in the CRP between the 2 groups disappeared (OR 1.28, 95% CI: 0.86–1.91, p = 0.232). No statistically significant difference was noted in the rates of implantation and miscarriage.ConclusionsThe current FET should not be cancelled if the ovulation time exceeds the predicted period based on the length of the previous menstrual cycle in the light of no negative effect on the pregnancy outcome.

IGF-1 and IGFBP-3 serum concentrations in patients undergoing programmed frozen-thawed embryo transfer of euploid PGT-A embryos

IGF-1 has been shown to induce embryonic development in vitro, but at high concentrations exhibits toxic effects by decreasing embryonic glucose uptake. IGFBP-3 binds IGF-1, modulating its bioavailability and is essential to its function. Prior reports have associated elevated follicular phase IGF-1 with pregnancy loss in frozen-thawed embryo transfer in natural cycles (n-FET), but an association in programmed (p-FET) cycles or in the luteal phase has not been analyzed. We sought to determine whether serum levels of IGF-1 and IGFBP-3 correlate with the outcome of p-FET cycles. Retrospective cohort study. Patients who underwent p-FET of single, good quality (Grade ≥2BB), PGT-normal embryos were included in the study. GnRH-agonist suppression was started in the preceding luteal phase, overlapped with estradiol patches, and stopped with the start of progesterone. Serum samples were collected on cycle day 2 (CD2), the day of progesterone start (CDP4), and cycle days 28 (CD28) and 30 (CD30). Embryo transfer occurred on the 7th day of P4 administration. Serum levels of IGF-1 and IGFBP-3 were compared between those who did not achieve pregnancy, those who had a live birth, and those who had a pregnancy loss. Serum IGF-1 and IGFBP-3 levels were measured by chemiluminescent immunoassays using the Immulite 2000 XPi. Statistical analysis was performed using Chi-square and Fisher’s exact test. P<0.05 was deemed statistically significant. A total of 102 patients who underwent p-FET of single euploid embryos over 2 years were analyzed. The mean age at retrieval was 35.7 ± 4.1 years, BMI 24.2 ± 4.8 kg/m2, gravity 1.8 ± 1.6, parity 0.4 ± 0.6 and peak endometrial thickness 9.7 ± 2.0 mm. 76.5% of patients were pregnant and 78.2% of those had a live birth. Among women who conceived, those who had a subsequent pregnancy loss had significantly higher serum IGF-1 levels on CDP4 and CD28 compared to those who achieved live birth when analyzing patients whose serum IGF-1 levels were above the mean value of IGF-1 level on CDP4 (136 ng/ml, p= 0.044) and CD28 (138 ng/ml, p=0.007), and between patients with CD28 IGF-1 levels one standard deviation above the mean (≥160 ng/ml, p=0.007). There was no significant difference in the serum levels of IGFBP-3 in any of the treatment cycle days.Tabled 1p-FET, Deliveredp-FET, Pregnancy losspIGF-1 CDP4 (≥ mean value)63.6%33%0.044IGF-1 CD 28(≥ mean value)58%14%0.044IGF-1 CD28 (≥ 160 ng/ml)70.8%14%0.007 Open table in a new tab In p-FET cycles with transfer of a single, euploid, high quality embryo, IGF-1 serum levels on day of progesterone start and CD28 are significantly higher in patients who subsequently had a pregnancy loss compared to those who had a live birth. This is in contrast to the findings of prior studies in n-FET.

The window is wide: flexible timing for vitrified-warmed embryo transfer in natural cycles.

What is the optimal timing for transfer in natural cycle vitrified-warmed embryo transfers (NC-VET)? This retrospective cohort study uses data from a large university-affiliated IVF clinic. The study included 341 NC-VET cycles with autologous oocytes and non-preimplantation genetic testing, vitrified embryos from January 2013 to September 2017. Each cycle was classified by timing of embryo transfer in relation to LH surge ≥20IU/l. Group 1: LH ≥20IU/l one day and blastocyst was transferred 6 days later; Group 2: LH ≥20IU/l two consecutive days and blastocyst was transferred 6 days after the initial surge; Group 3: LH ≥20IU/l two consecutive days and blastocyst was transferred 7 days after the initial surge. The primary outcome was ongoing pregnancy rate (OPR). The secondary objective was to compare OPR in relation to serum oestradiol dynamics and progesterone concentration (according to threshold 1.0ng/ml) 6 days prior to embryo transfer. OPR were similar for all three groups (66.8%, 65.0%, 62.9% for Groups 1, 2 and 3, respectively). When stratified according to oestradiol and progesterone, no significant differences were noted in OPR. The results suggest that the timing of blastocyst transfer in a natural cycle after LH surge is flexible within 24h. Outcomes are equally good with day of embryo transfer 6 or 7 days after LH surge date. Oestradiol dynamics and progesterone concentration 6 days prior to NC-VET did not have a significant impact on OPR.

Does the use of gonadotropin-releasing hormone antagonists in natural IVF cycles for poor responder patients cause more harm than benefit?

Poor ovarian response to controlled ovarian stimulation (COS) is one of the most critical factors that substantially limits the success of assisted reproduction techniques (ARTs). Natural and modified natural cycle IVF are two options that could be considered as a last resort. Blocking gonadotropin-releasing hormone (GnRH) actions in the endometrium via GnRH receptor antagonism may have a negative impact on endometrial receptivity. We analysed IVF outcomes in 142 natural (n = 30) or modified natural (n = 112) IVF cycles performed in 82 women retrospectively. A significantly lower proportion of natural cycles reached follicular aspiration compared to modified natural cycles (56.7% vs. 85.7%, p < 0.001). However, the difference between the numbers of IVF cycles ending in embryo transfer (26.7% vs. 44.6%) was not statistically significant between natural cycle and modified natural IVF cycles. Clinical pregnancy (6.7% vs. 7.1%) and live birth rates per initiated cycle (6.7% vs. 5.4%) were similar between the two groups. Notably, the implantation rate was slightly lower in modified natural cycles (16% vs. 25%, p > 0.05). There was a trend towards higher clinical pregnancy (25% vs. 16%) and live birth (25% vs. 12%) rates per embryo transfer in natural cycles compared to modified natural cycles, but the differences did not reach statistical significance.

Optimal timing of frozen embryo transfer in natural cycles based on monitoring the ovulatory surge

Optimal timing of frozen embryo transfer in natural cycles based on monitoring the ovulatory surge

Changes in estrone and estradiol levels during follicle development: a retrospective large-scale study.

BackgroundThe improved reagent for measuring estradiol (E2), the ST AIA-PACK iE2 reagent, has a higher specificity for the measurement of E2 levels than the original ST AIA-PACK E2 reagent, because of its lower cross-reactivity with estrone (E1). As we had E2 data obtained with either of the reagents, we analyzed changes in E1 and E2 levels during follicle development.MethodsThe study included 14371 serum hormone measurements from 4412 patients who underwent oocyte retrieval or frozen/thawed embryo transfer in natural cycle in vitro fertilization in Shinbashi YUME clinic, Tokyo, between June 2011 and May 2014. The age of the patients ranged from 24 to 48 year (mean and standard deviation, 39.8 ± 4.0 year). Patients were categorized into three age groups (<38 year, 38–40 year, and >40 year) and into 10 groups of largest follicle diameter from 11 to 20 mm, with 1-mm intervals. Serum E2 levels were measured in the follicular phase with either the ST AIA-PACK E2 reagent or the ST AIA-PACK iE2 reagent, and the data were compared. Also, for 26 randomly selected samples, E2 was measured using both reagents, together with E1 and E3, and the E1/E2 ratios were compared.ResultsE2 concentrations measured with the ST AIA-PACK iE2 reagent were significantly lower than those measured with the ST AIA-PACK E2 reagent in the largest follicle diameter category of 11–17 mm in the <38 year group, in the largest follicle diameter category of 11–18 mm in the 38–40 year group, and in the largest follicle diameter category of 11–15 mm in the >40 year group. The serum E1/E2 ratio in the 26 samples was 3.4 ± 1.1 and 0.7 ± 0.1 in the early follicular phase and in the ovulatory phase, respectively.ConclusionsThe difference between the E2 concentrations measured with the ST AIA-PACK E2 reagent and the ST AIA-PACK iE2 reagent tended to decrease as the follicle diameter increased, particularly in the older patients, which suggests E1 secretion is more abundant in the early follicular phase and in younger patients than in the ovulatory phase and in older patients.

Effect of preovulatory progesterone elevation and duration of progesterone elevation on the pregnancy rate of frozen–thawed embryo transfer in natural cycles

To assess the incidence of P elevation (PE) in natural cycles and evaluate its effect on frozen-thawed embryo transfer cycles performed in natural cycles (FET-NC). Retrospective analysis. A tertiary assisted reproductive unit. Subfertile woman who did not conceive in their stimulated IVF cycle and underwent the first FET-NC cycle. Achieved serum samples were assayed for P concentrations from the day of LH surge up to 3 days before the surge. The cutoff level of PE was defined as 5 nmol/L. Clinical and ongoing pregnancy rates. The incidence of PE in natural cycles was 173 of 610 (28.4%). There were no significant differences in both clinical and ongoing pregnancy rates (39.0% vs. 37.3% and 32.5% vs. 31.7%) between those with vs. without PE on the day of LH surge. If PE lasted for 2 days or more, there was a significant reduction in the clinical pregnancy rate (39.4% vs. 20.7%). Using multivariate logistic regression, women's age, PE for 2 days or more, and the number of top-quality embryos were the significant factors for clinical pregnancy rates in FET-NC. The incidence of PE in FET-NC was similar to that in stimulated cycles. Progesterone elevation for 2 days or more before the LH surge impaired the clinical pregnancy rate of FET-NC, whereas PE on the day of LH surge only did not have such an adverse effect.

Clinical value of serum estradiol and trans-vaginal ultrasonography for pregnancy outcomes in frozen-thawed embryo transfer in natural cycles

Clinical value of serum estradiol and trans-vaginal ultrasonography for pregnancy outcomes in frozen-thawed embryo transfer in natural cycles

Outcome of frozen-thawed embryo transfer in natural cycles with spontaneous ovulation versus hCG triggering and hormone replacement therapy

Outcome of frozen-thawed embryo transfer in natural cycles with spontaneous ovulation versus hCG triggering and hormone replacement therapy

Luteal phase progesterone increases live birth rate after frozen embryo transfer

To see if progesterone support has a beneficial effect on live birth rate after frozen embryo transfer in natural cycles. Prospective randomized controlled trial. University-based hospital. Four hundred thirty-five women undergoing embryo transfer in natural cycles. The women received either vaginal progesterone, 400 mg twice a day from the day of embryo transfer in natural cycles, or no progesterone support. Live birth rate, biochemical pregnancy rate, pregnancy rate, and spontaneous abortion rate. Live birth rate were significantly greater in women receiving vaginal progesterone as luteal phase support after frozen-thawed embryo transfer in natural cycles compared with those who did not take progesterone. There were no differences in biochemical pregnancy rate, pregnancy rate, or spontaneous abortion rate. Progesterone supplementation improves live birth rate after embryo transfer in natural cycles.

"ln vitro" fertilization and embryo transfer in natural cycles: Our five years experience

"ln vitro" fertilization and embryo transfer in natural cycles: Our five years experience