Higher miscarriage rate in subfertile women with endometriosis receiving unbiopsied frozen-warmed single blastocyst transfers.

Background: Assisted reproductive technology treatment is recommended to overcome endometriosis-associated infertility but current evidence is controversial. Endometriosis is associated with lower antral follicle count (AFC) and oocyte yield but similar clinical outcomes compared to controls. Unaffected ovarian stimulation response and embryological outcomes but lower clinical pregnancy and live birth rates and higher miscarriage rates have been reported, implying direct impact on endometrial receptivity. With evidence emerging on the benefit of frozen-warmed and blastocyst stage transfer, we investigated ART outcomes in endometriosis using homogeneous case-control groups. Methods: This is a retrospective observational case-control study including n = 66 frozen-warmed unbiopsied single blastocyst transfers of patients with endometriosis and n = 96 of women exhibiting idiopathic sterility. All frozen-warmed transfers followed artificial endometrial preparation. Results: In control women, the mean number of oocytes recovered at oocyte pick up was higher compared to women with endometriosis (15.3 ± 7.1 vs. 12.7 ± 5.2, p = 0.025) but oocyte maturation index (mature oocytes/total oocytes at oocyte pick up) was significantly higher for endometriosis (48.2% vs. 34.0%, p = 0.005). The same was shown for the subgroup of 44 endometriosis patients after endometrioma surgery when compared with controls (49.1% vs. 34.0%, p = 0.014). Clinical pregnancy rate was not higher in endometriosis but was close to significance (47.0% vs. 32.3%, p = 0.059) while live birth rate was comparable (27.3% vs. 32.3%, p = 0.746). Miscarriage rate was higher in the endometriosis group (19.7% vs. 7.3%, p = 0.018). A significantly higher AFC was observed in the control group in comparison with the endometriosis group (16.3 ± 7.6 vs. 13.4 ± 7.0, p = 0.014). Live birth rate did not differ when comparing all endometriosis cases (p = 0.746), ASRM Stage I/II and Stage III/IV (p = 0.348 and p = 0.888) with the control group but the overall pregnancy rate was higher in ASRM Stage I/II (p = 0.034) and miscarriage rate was higher in ASRM Stage III/IV (p = 0.030) versus control. Conclusion: Blastocyst transfers in women with endometriosis originate from cycles with lower AFC but higher share of mature oocytes than in control women, suggesting that endometriosis might impair ovarian reserve but not stimulation response. A higher miscarriage rate, independent of blastocyst quality may be attributed to an impact of endometriosis on the endometrium beyond the timing of implantation.

Retrospective comparison of pregnancy outcomes of fresh and frozen-warmed single blastocyst transfer: a 5-year single-center experience.

PURPOSE: To assess whether live birth rates (LBR) and maternal/neonatal complications differed following single fresh and frozen-warmed blastocyst transfer. METHODS: The present retrospective observational study analyzed 4,613 single embryo transfers (SET) (646 fresh and 3,967 frozen) from January 1, 2014, to December 31, 2018. Fresh embryo transfer at blastocyst stage was considered according to the age of the patient and her prognosis. In case of the risk of ovarian hyperstimulation syndrome, premature progesterone rise, non-optimal endometrial growth, or supernumerary embryos, cryopreservation with subsequent frozen embryo transfer (FET) was indicated. RESULTS: No differences in LBR were recorded. Fresh embryo transfers yielded an increase both in neonatal complications OR 2.15 (95% CI 1.20-3.86, p 0.010), with a higher prevalence of singletons weighting below the 5th percentile (p 0.013) and of intrauterine growth retardation (p 0.015), as well as maternal complications, with a higher placenta previa occurrence OR 3.58 (95% CI 1.54-8.28, p 0.003), compared to FET. CONCLUSION: LBR appears not to be affected by the transfer procedure preferred. Fresh embryo transfer is associated with higher risk of neonatal complications (specifically a higher prevalence of singletons weighting below the 5th percentile and of intrauterine growth retardation) and placenta previa. Reflecting on the increased practice of ART procedures, it is imperative to understand whether a transfer procedure yields less complications than the other and if it is time to switch to a "freeze-all" procedure as standard practice. TRIAL REGISTRATION: Clinical Trial Registration Number: NCT04310761. Date of registration: March 17, 2020, retrospectively registered.

Effect of the Re-Vitrification of Embryos at Different Stages on Embryonic Developmental Potential.

Background: Using re-vitrified human embryos for frozen-warmed embryo transfer (FET) is a valuable option when there are no other cryopreserved embryos to use, however, except for the PGT cases, no published data are available for FET with human embryos that were re-vitrified at different developmental stages. Objective: To evaluate the effect of re-vitrification of embryos at different stages on embryonic developmental potential. Method: This study included clinical retrospective and mouse experimental studies. For the retrospective study, a total of 25 FET cycles with re-vitrified day 3 embryos (re-vitrification group 1) and 54 FET cycles with re-vitrified day 5 blastocysts (re-vitrification group 2) between January 2015 and December 2019 were included in this study. The corresponding FET cycles with once-vitrified embryos were identified using propensity score (PS) matching according to the time of embryo transfer. For the mouse experimental study, we divided embryos into 5 groups: fresh (group 1), vitrified at the 8-cell stage (group 2), vitrified at the early blastocyst stage (group 3), vitrified at the 8-cell stage, and re-vitrified at the 8-cell (group 4) or early blastocyst stage (group 5). The fresh embryos was selected as control group. The primary outcome in this study was delivery outcomes. Results: No significant difference in delivery rate was detected between re-vitrification group 1 (24.00%) and the corresponding control group (28.00%). However, re-vitrification group 2 (46.3%) showed a significant decrease in delivery rate compared with the two corresponding control groups (63.89% and 64.12%) (P < 0.05). Our experiment using mouse embryos also confirmed the clinical data, and showed that re-vitrification at the blastocyst stage following the first round of vitrification at the 8-cell stage reduced the delivery rate. In addition, both re-vitrified groups showed a significantly higher expression level of BAX. However, only re-vitrification at the blastocyst stage increased the expression level of CASPASE3. Conclusions: Re-vitrification at the 8-cell and blastocyst stages has different effects on embryonic developmental potential, as re-vitrification at blastocyst stage following a previous vitrification at 8-cell stage reduced the delivery rate, while vitrification at the 8-cell stage twice achieved comparable pregnancy outcomes to the once-vitrified group.

Serum progesterone levels greater than 32.5 ng/ml on the day of embryo transfer are associated with lower live birth rate after artificial endometrial preparation: a prospective study.

BACKGROUND: Previous observational studies have highlighted the negative effects of serum hormone levels at the minimum threshold during frozen embryo transfer (FET) cycles. However, still the questions regarding the maximum threshold level, and the highest allowed dosage of hormonal medications remain unresolved. The present study was conducted to determine whether there is any relationship between the serum progesterone and estradiol levels on the day of ET, and live birth rate (LBR) in patients receiving HRT in FET cycles. METHODS: In this prospective cohort study, eligible women who were undergoing their first or second FET cycles with the top graded blastocyst stage embryos were included. All patients received the same HRT regimen. FET was scheduled 5 days after administration of the first dosage of progesterone. On the morning of ET, 4-6 h after the last dose of progesterone supplementation, the serum progesterone (P4, ng/ml) and estradiol (E2, pg/ml) levels were measured. RESULTS: Amongst the 258 eligible women that were evaluated, the overall LBR was 34.1 % (88/258). The serum P4 and E2 values were divided into four quartiles. The means of women's age and BMI were similar between the four quartiles groups. Regarding both P4 and E2 values, it was found that the LBR was significantly lower in the highest quartile group (Q4) compared with the others, (P = 0.002 and P = 0.042, respectively). The analysis of the multivariable logistic regression showed that the serum level of P4 on ET day, was the only significant predictive variable for LBR. The ROC curve revealed a significant predictive value of serum P4 levels on the day of ET for LBR, with an AUC = 0.61 (95 % CI: 0.54-0.68, P = 0.002). The optimum level of serum P4, with 70 % sensitivity and 50 %specificity for LBR, was 32.5 ng/ml. CONCLUSIONS: The present study suggests that a serum P4 value at the maximum threshold on the day of FET is associated with reduced LBR following blastocyst transfer. Therefore, measuring and monitoring of P4 levels during FET cycles might be necessary. However, the results regarding the necessity for the screening of serum E2 levels before ET, are still controversial, and further prospective studies are required.

Measuring the serum progesterone level on the day of transfer can be an additional tool to maximize ongoing pregnancies in single euploid frozen blastocyst transfers.

BACKGROUND: Endometrial preparation with hormone replacement therapy (HRT) is the preferred regimen for clinicians due to the opportunity to schedule the day of embryo transfer and for patients due to the requirement of fewer visits for frozen-warmed embryo transfers (FET). The increasing number of FETs raises the question of the serum P levels required to optimize the pregnancy outcome on the embryo transfer day. METHODS: This prospective cohort study includes patients who underwent single euploid FET. All patients received HRT with oestradiol valerate (EV) and 100 mg of intramuscular (IM) progesterone (P). FET was scheduled 117-120 h after the first IM administration of 100 mg P. The serum P level was analyzed 1 h before the embryo transfer (ET). In all cycles, only embryos that were biopsied on day 5 were utilized for FET. Next generation sequencing (NGS) was used for comprehensive chromosomal analysis. RESULTS: Overall, the ongoing pregnancy rate (OPR) was 58.9% (99/168). Data were then categorized according to the presence (Group I; n = 99) or the absence (Group II; n = 69) of an ongoing pregnancy. No significant differences regarding, female age, body mass index (BMI), number of previous miscarriages, number of previous live birth, sperm concentration, number of oocytes retrieved, number of mature oocytes (MII), rate of fertilized oocytes with two pronuclei (2PN), trophectoderm score, inner cell mass (ICM) score, endometrial thickness (mm), oestrodiol (E2) and P levels prior to IM P administration were found between two groups. The P levels on the day of ET (ng/ml) were significantly higher in Group I (28 (5.6-76.4) vs 16.4 (7.4-60) p = 0.039). The P level on the day of ET was a predictor of a higher OPR (p < 0.001 OR: 1.033 95%CI [1.009-1.056]) after multivariate analysis. The ROC curve showed a significant predictive value of serum P levels on the day of ET for OPR, with an AUC (95%CI) = 0.716 (0.637-0.795). The optimal cut-off value for prediction of the OPR was a P level of 20.6 ng/ml (71.7% sensitivity, 56.5% specificity). CONCLUSIONS: The present study suggests a minimum threshold of the serum P value on the day of ET that needs to be reached in HRT cycles to optimize the clinical outcome. Individualization of the P dosage should be evaluated in further studies.

Blastocoele expansion: an important parameter for predicting clinical success pregnancy after frozen-warmed blastocysts transfer.

OBJECTIVE: To assess the predictive value of each individual morphological parameter: blastocoele expansion degree, inner cell mass (ICM), and trophectoderm (TE) grades on the clinical pregnancy outcome in frozen-warmed embryo transfer (FET) cycles. METHODS: This is a retrospective cohort study, including 1154 FET cycles receiving vitrified-warmed one or two blastocysts transfer from August 2011 through to May 2018. The correlation between blastocyst morphology parameters and clinical outcome after FET was assessed. RESULTS: In the subgroup analysis based on clinical pregnancy, the patients who achieved clinical pregnancy had a significantly higher degree of blastocyst expansion (3.69 ± 0.68 vs. 3.53 ± 0.78, P = 0.000) and had a thicker endometrium (9.65 ± 1.63 vs. 9.28 ± 1.64) compared with those with non-clinical pregnancy. The logistic regression analysis showed that among the three blastocyst morphology parameters, only the blastocoele expansion degree was significantly correlated with the clinical pregnancy outcome and had ability to predict the outcome after FET cycles with one or two vitrified-warmed blastocysts transferred. Both ICM and TE stages were not associated with pregnancy outcomes. CONCLUSIONS: The blastocoele expansion degree may be essential for successful pregnancy and should be given priority when selecting frozen blastocyst for transfer.