Vitrified-warmed Embryo Transfer Cycles Research Articles

A model for predicting low progesterone levels on the day of embryo transfer in hormonally prepared vitrified-warmed embryo transfer cycles: A secondary analysis of a prospective cohort study.

To develop a model that predicts low progesterone (P) levels on the day of embryo transfer (ET) based on patient and cycle characteristics, including serum estradiol (E2 ) concentration after vaginal administration of micronized E2 for endometrial preparation. A prospective cohort of 193 patients scheduled for cryopreserved blastocyst transfer during an artificial endometrial preparation cycle, using micronized E2 vaginally for first 4 days (4 mg/day), followed by oral administration (6 mg/day). Blood sampling for E2 was performed prospectively on day-5 of vaginal administration and analysis was performed retrospectively. On sixth day of P treatment (daily 300 mg of vaginal micronized P tablets), P levels were measured on ET day. Primary outcome measure was serum P levels after vaginal E2 administration. Patients with low P levels on the day of ET (<7.8 ng/mL, 25th percentile) were heavier (p < 0.001) and exhibited lower day 5 serum E2 levels (p < 0.001) compared with patients with adequate P levels. Multivariate linear regression analysis revealed that weight (p = 0.003) and day 5 E2 levels (p < 0.001) were independently associated with the P levels. The sensitivity, specificity, and positive and negative predictive values (%) were 71.4, 55.6, 35.4, and 85.1 for weight ≥ 65 kg; 71.4, 61.8, 38.9, and 86.4 for day 5 E2 ≤ 1615 pg/mL; 59.2, 83.3, 54.7, and 85.7 for the combination of these two variables; and 82.9, 62.5, 54.7, and 87.0 for the sequential inclusion of these variables, respectively. Low day 5 E2 levels following vaginal administration and high weight are independently associated with low P levels on the day of ET. Predictive performance is enhanced when these variables are considered sequentially or in combination.

Effect of exposed-to-air frequency of cryopreserved embryo on clinical outcomes of vitrified-warmed embryo transfer cycles: a retrospective analysis of 9,200 vitrified-warmed transfer cycles

BackgroundCryopreservation of embryos plays a major role in the in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment. However, the storage condition of the cryopreserved embryo can change temporarily due to repeated retrieval of the embryo from the liquid nitrogen (LN2) tank during the practical application during cryopreservation. Whether the implantation potential of a cryopreserved embryo will be damaged when the cane containing it is temporarily exposed to air due to the transfer between the LN2 tank and LN2 container is yet to be elucidated. Also, whether the exposed-to-air frequency (EAF) of cryopreserved embryos influences the clinical outcomes is unclear.ObjectiveTo investigate whether the EAF of cryopreserved embryo affects the clinical outcomes of vitrified-warmed embryo transfer.MethodsA total of 9200 vitrified-warmed embryo transfer cycles were included in this study. All cycles were divided into five groups according to different EAFs (2, 4, 6, 8, or ≥ 10). Post-warming survival rates and clinical outcomes, including implantation, clinical pregnancy and live birth rates were investigated. Kruskal–Wallis test and Pearson’s chi-squared tests were used to compare the patient characteristics and clinical outcomes among the five groups. Furthermore, multivariate logistic regression analyses were conducted to investigate the association between EAF and clinical outcomes.ResultsNo significant differences were observed in the positive HCG rate, implantation rate and live birth rate (P > 0.05) among five EAF groups with respect to D3 embryo, D5 blastocyst and D6 blastocyst. Post-warmed survival rate of D3 embryos (P = 0.015) differed significantly among the five EAF groups, but it was not EAF-dependent. Although clinical pregnancy was different among the five groups with respect to D5 blastocyst (P = 0.042), multivariate logistic regression analysis adjusted for confounding variables suggested that EAF did not adversely affect clinical pregnancy or live birth.ConclusionThese findings indicated that human vitrified embryos in the open system could be repeatedly retrieved from the LN2 tank without affecting the implantation potential of the embryo.

Genital tract dysbiosis in infertile women with a history of repeated implantation failure and pilot study for reproductive outcomes following oral enteric coating lactoferrin supplementation

We prospectively investigated if oral enteric coating lactoferrin supplementation improves the reproductive outcomes in infertile women with a history of repeated implantation failure (RIF) and non-Lactobacillus-dominant (Lactobacillus rate < 90%) microbiota (NLDM) in vaginal secretions (VS)/endometrial fluid (EF). Paired VS/EF samples were obtained from RIF women and control infertile women (non-RIF group) for microbiome analysis. Chronic endometritis (CE) was diagnosed histopathologically and hysteroscopically. In a pilot study, oral enteric coating lactoferrin (700mg/day, at least 28 consecutive days) was administered to eligible patients with NLDM in VS/EF. Their reproductive outcomes in the subsequent vitrified-warmed embryo transfer cycles were followed up. While CE was more prevalent (OR 2.41, 95% CI 1.02-5.63, p = 0.042) in the RIF group (29.1%, n = 117) than in the non-RIF group (14.5%, n = 55), The NLDM rate was similar between the two groups (44.4 vs 52.7%). Lactoferrin supplementation improved NLDM in 43.2% of RIF women (n = 37). Within the RIF group, the live birth rate in the subsequent cycles was higher (OR 10.67, 95% CI 1.03 - 110.0, p = 0.046) in women with improved microbiota (57.1%, n = 14) than in those with unimproved microbiota (11.1%, n = 9). Unlike CE, NLDM was not unique to RIF but was common in infertile women. Although the therapeutic effect of the oral lactoferrin supplementation on NLDM was limited in a pilot study, the reproductive outcomes were better in RIF women who overcame NLDM than in those who failed. Randomized controlled trials are required to confirm the results. TRIAL REGISTRATION NUMBER AND DATE FOR PROSPECTIVELY REGISTERED TRIALS: UMIN-CTR 000036990, June 7, 2019.

A nomogram to assist blastocyst selection in vitrified-warmed embryo transfer cycles.

The purpose of the study was to establish a mathematical model to help rank the order of blastocysts and assist selection of which blastocysts to warm in vitrified-thawed embryo transfer cycles. A total of 2862 women who underwent first vitrified-thawed single blastocyst transfer (SBT) between July 2015 and July 2019 were retrospectively recruited and randomized into a training set (n=2289) and testing set (n=573). Least absolute shrinkage and selection operator (LASSO) regression was used to screen the factors critical to live birth (LB). Subsequently, a nomogram model was established to convert the effect of each factor on LB into a measurable score. The efficacy of the model was then evaluated by the receiver operating characteristic and calibration curve. The performance of the model was also internally tested in the testing set. Maternal age, endometrial thickness, oocyte number, day-3 embryo quality, blastocyst morphology, and blastulation day were selected as the critical predictors of LB in the vitrified-thawed SBT cycle and fitted into a nomogram model. The area under the curve (AUC) of the model was 0.67, and the AUC in the testing set was 0.64, which indicates moderate discrimination. The calibration curve showed good concordance between prediction and observation. Importantly, the score of each variable in the nomogram helped to rank the order of the blastocysts resulting in LB. The nomogram model can provide guidance for embryo selection in vitrified-thawed blastocyst transfer cycles, which may help to optimize the LB rate.

Pregnancy outcomes after fresh versus vitrified-warmed embryo transfer in women with adenomyosis: a retrospective cohort study

Research questionIs the singleton live birth rate superior for vitrified-warmed versus fresh embryo transfer in women with adenomyosis? DesignThis cohort study retrospectively analysed data from the Reproductive Hospital Affiliated to Shandong University between January 2013 and December 2018. A total of 612 women diagnosed with adenomyosis, with 322 fresh embryo transfer cycles and 290 vitrified-warmed embryo transfer cycles, were included in this study. The primary outcome was singleton live birth. Outcomes were adjusted using multivariable logistic regression analysis. ResultsVitrified-warmed embryo transfer was associated with a higher rate of singleton live birth than fresh embryo transfer (25.9% versus 17.4%; P = 0.011). Although there was a trend towards a lower miscarriage rate after vitrified-warmed embryo transfer, the difference did not reach statistical significance (31.3% versus 40.6%; P = 0.111). The clinical pregnancy rate was comparable in the two groups (44.1% versus 44.4%; P = 0.946). Vitrified-warmed embryo transfer also resulted in a lower risk of preterm birth than fresh embryo transfer (7.0% versus 17.5%; P = 0.010). ConclusionsVitrified-warmed embryo transfer may be associated with better pregnancy outcomes than fresh embryo transfer among women with adenomyosis. It seems that vitrified-warmed embryo transfer is more appropriate for specific populations.

RELATIONSHIP BETWEEN TEMPORAL CHANGES OF ENDOMETRIAL BLOOD FLOW IMPEDANCE IN A NATURAL AND HORMONE REPLACEMENT CYCLE AND PREDICTION OF PREGNANCY DURING VITRIFIED-WARMED EMBRYO TRANSFER

Frozen-thawed embryo transfer (ET) is performed in a natural or hormone replacement therapy (HRT) cycle for endometrial preparations. However, how to determine which endometrial preparation method is suitable for the individual is unknown.This study was to examine the relationship between the temporal changes in endometrial blood flow impedance during natural and HRT cycles and clinical outcomes in vitrified-warmed ET. A single-center retrospective observational cohort study. This study was approved by the institutional review board of the Fukushima Medical University. This study included a total of 60 women, 28 with natural and 32 with HRT cycles, who underwent vitrified-warmed ET. Uterine radial artery resistance index (RA-RI) was measured during the natural and HRT cycles at the early follicular phase, days of the human chorionic gonadotropin trigger during a natural cycle or start of progesterone administration during the HRT cycle, and the day of ET. The association between the RA-RI at the different measurement point and the pregnancy were examined in the natural and HRT cycles by univariate analysis and multivariate logistic analysis. Receiver-operating characteristic analysis was used to determine the cut-off value of the RI with respect to pregnancy in natural and HRT cycles. The area under the curves (AUC) and their 95% confidence intervals (CI) were calculated. The clinical pregnancy rates of the natural and HRT cycles were 32.1% and 34.4%, respectively. In the univariate analysis, the RA-RI at the early follicular phase was significantly lower in the pregnant group than that in the non-pregnant group in the natural but not HRT cycle (P=0.04). In the multivariate logistic analysis, the RA-RI at the early follicular phase was an independent predictive factor for pregnancy in the natural but not HRT cycle (P=0.02). The odds ratio for pregnancy was 0.7 (95% CI, 0.52–0.95) when the levels of RA-RI at the early follicular phase was increased by 0.01 in the natural cycle. With the natural cycle, the area under the receiver-operating characteristic curves for the RA-RI at the early follicular phase with a threshold of 0.68 was 0.75 (95% CI, 0.57–0.93). The positive predictive and negative predictive values were 0.53 (95% CI, 0.37–0.59) and 0.92 (0.74–0.99), respectively. With the natural cycle, the RA-RI at the early follicular phase was associated with pregnancy, and this might have a potential in predicting pregnancy in vitrified-warmed ET cycles. Our findings suggest that RA-RI at the early follicular phase might be an effective and useful tool in choosing natural or HRT cycles for vitrified-warmed ET. This provides a clue to the individualization of the choice of an endometrial preparation method during the frozen-thawed ET.

Poor Embryo Quality Is Associated With A Higher Risk of Low Birthweight in Vitrified-Warmed Single Embryo Transfer Cycles.

BackgroundPrevious studies have reported the association between embryo quality and perinatal outcomes in fresh cycles, after cleavage-stage or blastocyst embryo transfer, and found no significant difference. However, in terms of vitrified-warmed embryo transfer cycles, the impact of embryo quality on neonatal and maternal outcomes has not been evaluated.ObjectivesTo explore the association between the quality of a single vitrified-warmed embryo and perinatal outcomes.MethodsThis retrospective study included 2403 live-born singletons derived from single vitrified-warmed embryo transfer cycles during January 2006 and July 2018. Neonatal and maternal outcomes were compared between singletons resulting from the use of single good quality embryo (GQE) (n = 1854) and single poor quality embryo (PQE) (n = 549) and analyzed in the group of cleavage-stage embryo transfer and the group of blastocyst transfer, respectively.ResultsA significantly higher risk of low birthweight (LBW, birthweight <2500 g) was observed in the singletons derived from the transfer of single PQE compared with those derived from the transfer of single GQE both in cleavage and blastocyst stages (cleavage-stage, AOR 2.62, 95% CI 1.27–5.37; blastocyst stage, AOR 1.98, 95% CI 1.06–3.70). An increased risk of preterm birth (PTB, gestational age <37 weeks) was also observed in singletons born after transfer of a PQE of cleavage-stage compared with those after a GQE of cleavage-stage (AOR 2.40, 95% CI 1.28–4.49). The transfer of single poor quality blastocyst was associated with a higher risk of placenta previa compared with the transfer of single good quality blastocyst (AOR 2.65, 95% CI 1.26–5.57). Other maternal complications, neonatal malformations, and neonatal complications were similar between compared groups.ConclusionIn vitrified-warmed cycles with single embryo transfer, poor embryo quality would result in a significantly higher risk of LBW, regardless of cleavage-stage or blastocyst embryo transfer. Meanwhile, the transfer of poor cleavage-stage embryo was also associated with an increased incidence of PTB.

Impact of Day 7 Blastocyst Transfer on Obstetric and Perinatal Outcome of Singletons Born After Vitrified-Warmed Embryo Transfer.

BackgroundExtended embryo culture has been reported to affect perinatal outcome regarding higher risks of large for gestational age (LGA) and preterm birth (PTB) yet decreased risk of small for gestational age (SGA). However, existing data about the obstetric outcome and the safety for offspring resulting from the transfer of day 7 blastocysts is rare.ObjectivesTo compare obstetric and perinatal outcome using embryos vitrified on day 7 with those vitrified on day 3, day 5, and day 6.MethodsData were collected from 4489 infertile women who gave birth to live-born singletons after vitrified-warmed embryo transfer cycles from January 1, 2006 to December 31, 2017. Singletons were compared depending on the age of embryos. Main perinatal outcome parameters included PTB (gestational age < 37 weeks), very PTB (VPTB, gestational age < 32 weeks), LGA (birthweights > 90th percentiles), and SGA (birthweights < 10th percentiles). Obstetric outcomes included gestational diabetes (GDM), pregnancy-induced hypertension (PIH), preterm premature rupture of membranes (PPROM), pre-eclampsia, placenta previa, placental abruption, and postpartum hemorrhage. Propensity score matching (PSM) was used to adjust the confounding factors across groups and then analyze the association between in vitro culture period and the outcome measures.ResultsAfter PSM, the transfer of day 7 blastocysts was associated with higher birth weight Z-scores and increased incidence of very large for gestational age (VLGA) compared with the transfer of day 3 cleavage-stage embryos while the incidence of PTB, low birth weight (LBW), SGA did not reach statistical significance. Moreover, comparable perinatal outcome was found in the comparison of day 7 vs. day 5 and day 7 vs. day 6. Day 7 blastocysts did not result in adverse obstetric outcome compared with day 3, day 5, and day 6 embryos, respectively.ConclusionIn vitrified-warmed transfer cycles, day 7 blastocysts were associated with adverse perinatal outcome regarding higher risk of VLGA compared with day 3 cleavage-stage embryo, while blastocysts with diverse growth rates embrace similar developmental viability regardless of blastocysts vitrified on day 5, day 6, or day 7.

Vitirifiye embriyo transfer sikluslarında artifisyel endometrial hazırlıkta östrojen takviyesinin kısa süre kullanımı ile reprodüktif sonuçlar arasındaki ilişki

Amaç: Vitrifiye embriyo transfer (VET) sikluslarında progesteron (P) desteği öncesi östradiyol (Ö) kullanım süresinin canlı doğum oranını (CDO) etkileyip etkilemediğini değerlendirmek Gereçler ve Yöntem: Bu retrospektif kohort çalışma, Ekim 2015 ve Ekim 2017 arasında Amerikan Hastanesi Üremeye Yardımcı Teknikler Ünitesi’nde GnRH agonist uygulamasız artifisyel endometriyum hazırlığı ile tek blastokist transferi yapılan tüm hastaları kapsamaktadır. Sadece G1 ve G2 iyi kalitede blastokistler dondurulmuştur. &amp;gt;43 yaş olanlar, tedavi siklus kayıtlarında eksik verileri olan veya takipten çıkan hastalar çalışma dışı bırakılmıştır. Tüm hastalara âdetin 2. günü 6 mg sabit dozdan oral Ö tedavisi başlanmıştır. Östradiyol kullanım süresi embriyo transfer (ET) günü planlamasına göre 8 ile 14 gün arası değişmektedir. Toplamda 241 hastanın VET siklusu Ö kullanım sürelerine göre (Grup 1: &amp;lt;12 gün, n=105; Grup 2: ³12 gün, n=136) analiz edilmiştir. Çalışmanın primer sonuç değişkeni CDO’ dır. Bulgular: Toplam 241 VET siklusundaki P kullanımı öncesi E kullanım süresi: 8 gün (%3), 9 gün (%8), 10 gün (%16), 11 gün (%16.5), 12 gün (%22.5), 13 gün (%20.5), 14 gün (%13.5) şeklinde dağılım göstermektedir. Östradiyol takviyesinin 12 günün altında kullanımının 12 gün üzerinde kullanımına kıyasla CDO üzerine anlamlı etkisi yoktur (OR=1.25; %95 CI [0.75-2.1], p=0.38). Klinik gebelik, erken ve fetal kayıp oranları da gruplar arasında benzerdir. Ortalama endometrial kalınlık gruplar arasında benzerdir (9.5mm). Östradiyol takviyesinin reprodüktif sonuçlarla ilişkisi her gün için ayrı ayrı değerlendirildiğinde de anlamlı bir fark saptanmamıştır Sonuç: Vitrifiye embriyo transfer sikluslarında genel kabul görenden daha kısa östradiyol kullanımı canlı doğum oranlarını etkilememekte, abort riskini artırmamaktadır. Bu durum test edilmemiş ancak kuvvetle kabül görmüş bu protokolü sorgulanır kılmaktadır

Delayed blastocyst development dose not influence the outcome of vitrified warmed transfer cycles

During embryonic culture to the blastocyst stage, there are embryos that are delayed in their speed of development with a low implantation rate. Our objective of this study was to compare the clinical outcome according to the day of embryo freezing (day 5 or 6 following fertilization in vitro) when vitrification was postponed until expanded blastocysts developed. Cohort observational study We retrospectively investigated the vitrified-warmed embryo transfer cycles between Jan 2014 and Dec 2015 in Fertility center of CHA Gangnam medical center . Clinical outcome data consecutive of 1,056 vitrified-warming cycles were analyzed. The mean age of the patient was 35.8 ± 4.4 years. According to the time of the vitrification, embryos were divided into day 5 (1,788 embryos of 772 cycles) and day 6 (594 embryos of 284 cycles) group. Blastocysts were assigned to one of three groups scores according to score of embryos. We compared the clinical outcomes of vitrified-warmed blastocyst stage derived from day 5 and day 6. The mean number of blastocysts transferred per cycle, vitrified and transferred embryo score was not different (1.8 ± 0.5 vs. 1.8 ± 0.3, 9.5±0.8 vs. 9.5±1.0, 9.7±0.4 vs. 9.8±0.7, respectively). The survival rates were comparable between the day 5 and day 6 groups (90.15% vs. 88.68%). The clinical pregnancy and implantation rate (56.08 vs. 41.54%, 40.54% vs.29.46%, P<0.05, respectively) of the day 5 were significantly higher than day 6. The abortion rate was lower in day5 as compared to day 6 (13.16% vs 16.10%) but no significant difference. The pregnancy, implantation and abortion rate of high grade blastocyst vitrified on day 5 and day6 was not different (59.08 vs. 51.34%, 48.32% vs.42.76%, 11.45% vs. 13.45%, respectively). Vitrified-warmed blastocyst stage derived from day 5 was significantly higher evidence for clinical pregnancy rate and implantation rate. But lower evidence for abortion rate were frozen either on day 5 or day 6 but no significant difference. But good quality blastocysts that were vitrified on day 6 had similar developmental potential and pregnancy outcomes compared to those of on day5. Thus, the quality of the blastocysts were an important factor that affected the pregnancy outcomes of the vitrified-warmed transfer cycles.

Prognostic factors for patients undergoing vitrified-warmed human embryo transfer cycles: a retrospective cohort study

We examined the prognostic factors for pregnancy in 210 vitrified-warmed embryo transfer (ET) cycles in 121 patients. The univariate analysis showed that age, gravida, the number of cycles associated with infertility caused by endometriosis, the number of previous assisted reproductive technology (ART) treatment cycles, and the number of ICSI procedures were significantly lower in pregnant cycles compared with non-pregnant cycles. The percentages of ET using at least one intact embryo and of ET using at least one embryo that had developed further after warming were significantly higher in pregnant cycles compared with non-pregnant cycles. Multivariate logistic regression analysis showed that previous ART treatment cycles, ET with at least one intact embryo, and ET using at least one embryo that had developed further were independent prognostic factors for pregnancy in vitrified-warmed ET cycles. We conclude that fewer previous ART treatment cycles, ET using at least one intact embryo, and ET with embryos that have developed further after warming might be favourable prognostic factors for pregnancy in vitrified-warmed ET cycles.

Are perinatal outcomes affected by blastocyst vitrification and warming?

Transfer of cryopreserved-warmed embryos into an appropriately prepared uterus unaffected by controlled ovarian hyperstimulation is common in the practice of invitro fertilization. There is limited information on the effect of blastocyst vitrification and warming on perinatal outcomes. We sought to determine if perinatal outcomes are affected after the transfer of vitrified-warmed blastocysts compared to the transfer of fresh blastocysts, by comparing preeclampsia rate, birthweight, percentage of low birthweight, and preterm delivery rate between embryo transfer types. We performed a retrospective database cohort study of 289 fresh and 109 vitrified-warmed blastocyst transfer cycles at an academic medical center. Cycles were performed from July 2, 2009, through Dec. 8, 2014, and included infants born at ≥20 weeks gestational age, excluding donor egg cycles. We examined the association between transfer type (fresh or vitrified-warmed) and proportion of deliveries complicated by preeclampsia, preterm delivery(gestational age <37 weeks), and low birthweight (<2500 g). We assessed associations using generalized linear models, both unadjusted and adjusted, for maternal age, newborn sex, diabetes status, and parity. We observed more pregnancies complicated by preeclampsia following vitrified-warmed transfers (7.6%) compared to fresh embryo transfers (2.6%) (P= .023) (adjusted odds ratio, 3.1; 95% confidence interval, 1.2-8.4). Newborns resulting from vitrified-warmed embryo transfer cycles were similar to those resulting from fresh embryo transfer cycles with regard to low birthweight (7.4% vs 5.3%, P= .421), mean birthweight (3443 vs 3431 g, P= .865), and preterm delivery rate (9.2% vs 8.7%, P= .869). We conclude that embryo vitrification with warming may affect some perinatal outcomes since preeclampsia is increased compared to fresh blastocyst transfer. However, other perinatal outcomes such as low birthweight and preterm delivery rate are not affected. Fresh blastocyst transfers should be considered when possible as they may reduce the incidence of preeclampsia.

Effects of Different Trehalose Concentrations in a Warming Medium on Embryo Survival and Clinical Outcomes in Vitrified Human Embryos

Background/Aims: In the present study, we examined the effects of different concentrations of trehalose in a warming medium on both embryo survival and clinical outcomes in vitrified-warmed embryo transfer cycles. Methods: We retrospectively analyzed a total of 209 vitrified-warmed cycles from 177 patients who underwent in vitro fertilization or intracytoplasmic sperm injection and embryo transfer. Embryos were cryopreserved by the vitrification method and warmed in solutions containing either 0.5 or 1.0 <smlcap>M</smlcap> trehalose. We compared the 0.5 and 1.0 <smlcap>M</smlcap> trehalose warming solution groups with respect to the embryo survival rate after warming and clinical outcomes. Results: The embryo survival rate in the 1.0 <smlcap>M</smlcap> trehalose group (96.5%) was significantly higher than that in the 0.5 <smlcap>M</smlcap> trehalose group (57.0%). The percentage of embryo transfers after warming in the 1.0 <smlcap>M</smlcap> trehalose group (94.3%) was significantly higher than that in the 0.5 <smlcap>M</smlcap> trehalose group (83.7%). The clinical pregnancy rate in the 1.0 <smlcap>M</smlcap> trehalose group (25.0%) was significantly higher than that in the 0.5 <smlcap>M</smlcap> trehalose group (11.1%). Conclusion: Embryo survival and clinical pregnancy rates were higher when a 1.0 <smlcap>M</smlcap> trehalose solution was used than when a 0.5 <smlcap>M</smlcap> trehalose solution was used during the embryo warming process.

Intensified ovarian stimulation in a GnRH antagonist protocol with agonist triggering: a prospective, clinical feasibility study

The threat of severe ovarian hyperstimulation syndrome (OHSS) and the increase in discomfort for the patient has limited the feasibility of maximizing the oocyte yield per treatment cycle. A gonadotrophin-releasing hormone (GnRH) antagonist protocol with agonist triggering and vitrification of all 2PN oocytes can eliminate the risk of OHSS. This prospective, single-centre, cohort study in 30 good-responder IVF patients ≤ 36 years reports the feasibility of arbitrarily intensifying stimulation in a GnRH antagonist protocol in terms of tolerability, safety and efficacy. Ovarian stimulation was performed with 225-375IU FSH, induction of final oocyte maturation with 0.2mg GnRH agonist followed by vitrification of all 2 pronuclear (2PN) oocytes and repetitive vitrified-warmed embryo transfer cycles. Main outcomes were severe OHSS incidence, tolerability, assessed by a questionnaire, and cumulative live birth rate. On average, 17 oocytes were retrieved (range 4-42) and 8.4 oocytes at the 2PN stage were cryopreserved (range 3-22). No case of severe OHSS was observed (0%, 95 CI 0-11.4%). Tolerability was good. The cumulative live birth rate per patient undergoing at least one vitrified-warmed embryo transfer was 26.9% (7/26, 95% CI 13.7-46.1%). This approach can be explored in future larger-sized controlled studies.

Effect of laser zona thinning on vitrified–warmed embryo transfer at the cleavage stage: a prospective, randomized study

The aim of this study was to determine if laser zona thinning could improve the rates of pregnancy and implantation for vitrified-warmed embryo transfer at the cleavage stage. A total of 400 vitrified-warmed embryo transfer cycles were randomly assigned to either the test group or the control group. The zona pellucida of vitrified-warmed embryos in the patients of the control group was untreated, whereas in the test group it was partially thinned by laser just before embryo transfer. In the test group, the clinical pregnancy and implantation rates were significantly lower as compared with that of the control group (28.5 versus 43.0, P=0.002, and 11.2 versus 16.7, P=0.004, respectively). Therefore the results of this investigation show that laser zona thinning may have an unexpected adverse effect on the rates of clinical pregnancy and implantation of vitrified-warmed embryos at the cleavage stage.

Retrospective analysis of sex-ratio of offspring derived from embryos cultured for 5 days

Retrospective analysis of sex-ratio of offspring derived from embryos cultured for 5 days