Effect of Day 3 and Day 5/6 Embryo Quality on the Reproductive Outcomes in the Single Vitrified Embryo Transfer Cycles

Ovarian reserve and IVF/ICSI outcomes after various laparoscopic approaches in infertility patients with endometriomas and suspected compromised ovarian reserve: A retrospective study

OBJECTIVE

To assess the ovarian reserve and in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes after various laparoscopic approaches in infertile patients with endometriomas and suspected compromised ovarian reserve, and the operated and non-operated/healthy ovaries were also compared, aiming to determine the most appropriate laparoscopic approach for each patient.

METHODS

A total of 132 infertile patients with endometriomas and suspected compromised ovarian reserve (anti-Müllerian hormone [AMH] <2.0 ng/mL or antral follicle count [AFC] <8) were treated by various laparoscopic approaches at the Sir Run Run Shaw Hospital from January 2021 to December 2023, followed by IVF/ICSI. Patients were divided into three groups-group A (n = 33) received anhydrous alcohol instillation, group B (n = 65) underwent fenestration/coagulation, and group C (n = 34) underwent ovarian cystectomy. The clinical characteristics, ovarian reserve, and IVF/ICSI outcomes were evaluated among the three groups. The operated side and non-operated/healthy side in patients undergoing initial surgery were also compared.

RESULTS

The proportion of bilateral endometriomas was higher in group A (63.6%, 21/33) than in group B (40.0%, 26/65) and group C (32.4%, 11/34) (P = 0.023). There was no statistically significant difference in serum AMH in group A before and after surgery (median 1.32 [0.84-1.86 ng/mL] vs. 1.13 [0.59-1.86 ng/mL], P = 0.098). However, significant postoperative decreases were observed in groups B (median 1.30 [0.97-1.76 ng/mL] vs. 0.91 [0.50-1.23 ng/mL], P = 0.009) and C (median 1.52 [1.02-1.81 ng/mL] vs. 1.15 [0.76-1.67 ng/mL], P = 0.006). In group C, the follicle-stimulating hormone/luteinizing hormone ratio also increased postoperatively (median 1.75 [1.33-2.50] vs. 2.29 [1.84-3.61], P = 0.005), while no significant differences were seen in groups A (median 1.72 [1.56-2.80] vs. 2.89 [1.89-3.54], P = 0.096) and B (median 2.14 [1.67-2.82] vs. 2.37 [1.83-3.03], P = 0.189). The clinical pregnancy rate was significantly higher in group A than in group C (60.6%, 20/33 vs. 36.4%, 12/33; P = 0.042), but not significantly different between groups A and B (60.6%, 20/33 vs. 46.9%, 30/64; P = 0.143) or groups B and C (P = 0.220). Compared with the control group, there was a statistically significant difference in preoperative AFC in the group anhydrous ethanol instillation side (median 4.0 [2.0-5.0] vs. 2.0 [0.75-3.25], P < 0.001), the group fenestration/coagulation side (median 2.0 [0-3.0] vs. 2.0 [0.75-3.25], P < 0.001), and the group ovarian cystectomy side (median 2.0 [0-4.0] vs. 2.0 [0.75-3.25], P = 0.003), with no significant differences among the three groups themselves. Compared with the control group, significant differences were also observed between the group fenestration/coagulation side (median 2.0 [1.0-3.75] vs. 2.0 [1.0-3.0], P = 0.014) and the group ovarian cystectomy side (median 2.0 [1.0-4.0] vs. 2.0 [1.0-3.0], P = 0.040), in the 15-20 mm follicles, while no significant differences were found in the group anhydrous ethanol instillation side (median 3.0 [2.0-5.0] vs. 2.0 [1.0-3.0], P = 0.108).

CONCLUSION

This study suggests that laparoscopic anhydrous ethanol treatment prior to IVF/ICSI in infertile patients with ovarian endometrioma and suspected compromised ovarian reserve may be superior to fenestration/coagulation and ovarian cystectomy.

Chemical pregnancy in fresh and cryopreserved cycles, using day 3 (cleavage stage) and day 4 embryos (morula stage)

With the advancement in the embryo culture media, which supports nutrient requirements of embryos up to 5 to 6 days, there's a chance to select more viable embryos, which are more likely to result in pregnancy, compared to earlier stages. Also, there is a controversy regarding the frozen embryo transfer compared to the fresh type. To compare the chemical pregnancy rates between fresh embryo transfer (ET), and frozen embryo transfer (FET), on day 3 (cleavage), and day 4 (morula) of development. In this retrospective study, data of 242 fresh and 758 frozen embryo transfer cycles were obtained in one infertility center in Isfahan, Iran. The study's groups were assigned based on the day of fresh or frozen embryo transfer (day 3, or day 4 embryos) and the embryo grading. Chemical pregnancy was the main outcome measurement (implantation rates). The chemical pregnancy rate was higher in the good quality frozen embryo day 3 and transfer on day 4 group (40.1%). This rate was near the results of transferring the good quality frozen embryo on day 4 (39.2 %). There was no significant difference in the chemical pregnancy rate related to the number of transferred embryos (p = 0.55). The higher PRs, when the embryos were transferred on day 4, provided further support for the morula stage embryo transfer, possibly because of better synchrony with the endometrium. It is concluded that morula/compact embryos are good candidates for embryo transfer, which simultaneously reduces the number of transferred embryos.

Unveiling clinic variation in utilization of ICSI, PGT, and blastocyst transfer: a comprehensive study using the SART database (2014-2020)

PURPOSE

Many national recommendations have been made regarding practice patterns of assisted reproductive technology utilization (intracytoplasmic sperm injection (ICSI), preimplantation genetic testing (PGT), and blastocyst stage embryo transfer). This study seeks to assess individual clinic changes in practice behaviors from 2014 to 2020 in response to national guidelines.

METHODS

This retrospective cohort study examined data from individual clinics using the Society of Assisted Reproductive Technology Clinical Outcome Reporting System (SART-CORS) database. Each clinic was weighed individually and equally regardless of clinic volume to avoid skewing national data with larger-volume clinics. The trends of ICSI, PGT, and blastocyst stage embryo transfer were examined across five age groups (< 35, 35-37, 38-40, 40-42, and > 42).

RESULTS

ICSI usage from 2014 to 2020 increased in all age groups (p < 0.001). In 2020, more than half the clinics in this study utilized ICSI in ≥ 90% of IVF cycles (per oocyte retrieval). Utilization of prolonged embryo culture increased in all age groups across the seven years of this study, with a more extensive adoption of this practice in patients ≤ 40 years (p < 0.001). Between 2014 and 2020, PGT usage increased by 3-4 times across all age groups (p < 0.001). By 2020, PGT was performed after egg retrievals in approximately 40 to 50% (mean) of patients < 42 years old.

CONCLUSIONS

Nationally, the application of all three reproductive technologies (ICSI, PGT, and blastocyst stage transfer) has drastically increased. The authors suspect that these technology expansions are interrelated and may be associated with the rise of rates of PGT.

A Case Series Based on the Mixed Double-Embryo Transfer (MDET) Outcome in Patients With Recurrent Implantation Failure

Successful implantation of embryos depends on the synchronous cross-talks between the endometrial wall and the competent blastocyst within the window of implantation (WOI). Hence, the WOI has a major significance in assisted reproductive technology (ART). However, in some cases, women do not have fixed WOI in ART cycles in order to enhance the rate of successful clinical pregnancy. However, there have been stances where women do not have a fixed WOI, and it shifts in subsequent menstrual periods. This contributes to the chances of recurrent implantation failure (RIF). Another factor that contributes to RIF is erratic endometrial receptivity, which hinders the chances of successful implantation of the conceptus in the endometrium. This case series consists of four case studies where the patients were believed to be suffering from RIF due to variable WOI or erratic endometrial receptivity and the routine protocol followed nowadays failed to make them conceive. In order to resolve the condition, we proposed a novel strategy in an attempt to improve pregnancy rates in these cases. An innovative method of embryo transfer known as mixed double-embryo transfer (MDET), which involved the transfer of one day 3 embryo and one day 5 blastocyst on day 6 of progesterone, led to possible pregnancy outcomes. A viable pregnancy was validated based on the human chorionic gonadotropin (β-hCG) test report, and two of the cases delivered healthy babies. Thus, this case series provides a unique approach to addressing the issues of RIF. However, larger studies are required to validate the possible use of this technique.

Optimal number of high-quality cleavage-stage embryos for extended culture to blastocyst-stage for transfer in women 38 years and older

PURPOSE

We aimed to evaluate the pregnancy outcomes of cleavage-stage embryo transfers (ETs) for the first time and explore optimal number of high-quality cleavage-stage embryos for extended culture to blastocyst-stage in women of advanced maternal age (AMA).

METHODS

We retrospectively identified 1646 AMA women ≥ age 38 years for the first fresh ETs between January 2014 and December 2020 at our hospital. Double ETs were divided into three groups as follows: DET-HH (two high-quality embryos), DET-HL (one high-quality and one low-quality embryo), and DET-LL (two low-quality embryos) groups. We mainly analyzed the pregnancy outcomes of double cleavage-stage ETs with different embryo grades and blastocyst-stage ETs with different number of high-quality cleavage-stage embryos on day 3.

RESULTS

Our data indicated that the DET-HH group had significantly higher clinical pregnancy, ongoing pregnancy, and live birth rates than DET-HL and DET-LL groups (p < .05). For extended culture to blastocyst-stage with 2 (D3-2H), 3 (D3-3H), and 4 (D3-≥4H) high-quality cleavage-stage embryos, the D3-≥ 4H group had significantly higher ongoing pregnancy and live birth rates than D3-2H and D3-3H groups (p < .05). We observed that the number of high-quality embryos on day 3 was independently associated with live birth rate for blastocyst transfers (OR: 1.133, 95% CI 1.023-1.256, p = .017). There were no significant differences in the clinical pregnancy, ongoing pregnancy and live birth rates among DET-HH, D3-2H and D3-3H groups (p > .05).

CONCLUSIONS

Extended culture to blastocyst-stage for transfer was safe and recommended for AMA women with ≥ 4 high-quality embryos on day 3.

The optimal frozen embryo transfer strategy for the recurrent implantation failure patient without blastocyst freezing: thawing day 3 embryos and culturing to day 5 blastocysts

This study aimed to investigate the optimal frozen embryo transfer (FET) strategy for recurrent implantation failure (RIF) patients with three consecutive failed cleaved embryo implantations and no blastocyst preservation. This retrospective analysis was divided into three groups based on the FET strategy: thawed day 3 embryo transfer (D3 FET group); and extended culture of frozen-thawed day 3 embryos to day 5 blastocysts transfer (D3-D5 FET group); thawed blastocyst transfer (D5 FET group). Transplant cycle data were compared between the three groups. In total, 43.8% of vitrified-thawed cleavage embryos developed into blastocysts. Analysis of the three transplantation strategies showed that, compared with the D3 FET group, D3-D5 had a significantly better hCG-positivity rate and live-birth rate (P < 0.05). Pregnancy outcomes in the D3-D5 FET group and D5 FET group were similar regarding hCG-positivity rate, implantation rate, clinical pregnancy rate, and live-birth rate. Our findings propose two potentially valuable transfer strategies for patients experiencing repeated implantation failures. The D3-D5 FET approach presents a greater potential for selecting promising embryos in cases without blastocyst preservation; however, this strategy does entail the risk of cycle cancellation. Conversely, in instances where blastocyst preservation is an option, prioritizing consideration of the D5 FET strategy is recommended.

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

BACKGROUND

Cryopreservation 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.

OBJECTIVE

To investigate whether the EAF of cryopreserved embryo affects the clinical outcomes of vitrified-warmed embryo transfer.

METHODS

A 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.

RESULTS

No 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.

CONCLUSION

These 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.

Pregnancy Outcomes for Day 5 Versus Day 6 Single Frozen-thawed Blastocyst Transfer with Different Qualities of Embryos: A Large Matched-cohort Study

OBJECTIVE

This study aimed to determine whether the day of blastocyst expansion affects pregnancy outcomes in frozen-thawed blastocyst transfer (FBT) cycles.

METHODS

A retrospective match-cohort study was conducted. Patients who underwent blastocyst transfer in frozen-thawed cycles at day 5 or 6 were matched for potential confounding factors. A total of 2207 matched pairs of FBT cycles were included from January 2016 to December 2019 in our Reproductive Medicine Center.

RESULTS

The clinical pregnancy rate (CPR) and live birth rate (LBR) were significantly increased in day 5 blastocyst transfers when compared to day 6 blastocyst transfers, in terms of the same embryo quality. For FBT cycles with good-quality embryo, the CPR at day 5 and 6 was 61.30% and 57.56%, respectively (P=0.045), and the LBR was 44.79% and 36.16%, respectively (P<0.001). For FBT cycles with poor-quality embryo, the CPR at day 5 and 6 was 48.61% and 40.89%, respectively (P=0.006), and the LBR was 31.71% and 25.74%, respectively (P=0.019). The CPR for FBT cycles with good-quality embryo was statistically higher at day 6 than that at day 5 with poor-quality embryo transferred (57.56% vs. 48.61%, P=0.001). Maternal age, anti-Müllerian hormone (AMH), endometrial thickness, embryo quality, and the day of blastocyst expansion were independently correlated with the CPR and LBR. The FBT cycles at day 5 had significantly higher CPR (adjusted odds ratio [OR]=1.246, 95% confidence intervals [CI]: 1.097-1.415, P=0.001) and LBR (adjusted OR=1.435, 95% CI: 1.258-1.637, P<0.001) than those at day 6.

CONCLUSION

The embryo quality is the primary indicator for FBT cycles. Day 5 blastocysts should be preferred when the quality of embryo at day 5 is the same as that at day 6.

Incidence of complications among in vitro fertilization pregnancies

The use of assisted reproductive technology has increased in Romania in the past several years. Although most of these pregnancies are uncomplicated, in vitro fertilization is associated with an increased risk for adverse perinatal outcomes primarily caused by the increased risks of prematurity, gestational diabetes mellitus, and hypertensive disorders. Infertility can be caused by a variety of factors, including both male and female factors, and in some cases, the cause remains unknown. In our clinic, the etiology of infertility was known in most cases and was equally distributed between male and female factors. Women with gestational hypertension were significantly older. Patients with twin pregnancies were significantly younger than those with a single pregnancy. The prevalence of preterm newborns was 2.5 times higher than the global prevalence for prematurity.

No advantage of single day 6 good-quality blastocyst transfer versus single day 5 poor-quality blastocyst transfer in frozen-thawed cycles stratified by age: a retrospective study

BACKGROUND

Blastocyst developmental speed, morphological grading and patient age are associated with pregnancy outcomes of frozen-thawed cycles. This study aimed to compare the clinical and neonatal outcomes between poor-quality D5 blastocysts and good-quality D6 blastocysts stratified by patient age.

METHODS

A total of 1,623 cycles were divided into two groups: group A (n = 723) received one D5 poor-quality blastocyst; group B (n = 900) received one D6 good-quality blastocyst. Pregnancy and neonatal outcomes were compared among the four groups stratified by 35 years of age.

RESULTS

When patients were in the same age group, there was no significant difference in terms of age, body mass index, infertility duration, infertility type, fertilization method, proportion of endometrial preparation protocols, and endometrial thickness between D5 poor-quality and D6 high-quality blastocysts groups. Live birth rate of D5 poor-quality blastocysts was higher than that of D6 high-quality blastocysts for patients aged < 35 years (35.48% vs. 31.13%, p > 0.05), but there was no statistical difference. The same trend was showed for patients aged ≥ 35 years (29.09% vs. 21.28%, p > 0.05). Moreover, when patients were in the same age category, there was no significant difference in terms of gestational age, birth weight, birth height, and rates of preterm birth, low birth weight, and very low birth weight between groups A and B.

CONCLUSIONS

The preferential selection of poor-quality D5 blastocysts for transfer compared to high-quality D6 blastocysts is recommended, especially for advanced age patients. Single good-quality D6 blastocyst transfer can be considered for the acceptable live birth rate.

Rapamycin improves the quality and developmental competence of in vitro matured oocytes in aged mice and humans

Women over age 35 suffer from the inadequate number and poor quality of oocytes during assisted reproductive treatment, and making full use of the oocytes by in vitro maturation (IVM) is crucial. Rapamycin could improve the developmental competences of the post-maturation oocytes during in vitro aging, yet its effects on the IVM process of oocytes from an aged population were not clear. In this study, the immature oocytes from aged mice or older women underwent IVM with or without 10 nM rapamycin, followed by parthenogenetic activation or insemination and embryo culture. The developmental competence and quality of IVM oocytes in both groups were compared. The results showed that in aged mice, the maturation rate, activation rate, and cleavage rate of IVM oocytes were significantly elevated in the rapamycin group. Additionally, oocytes cultured with rapamycin presented decreased ROS levels, reduced chromosome aberration, and attenuated levels of γ-H2AX. During IVM of oocytes from older women, the GVBD rate, 24 h maturation rate, and 48 h maturation rate were increased in the rapamycin group, compared with those in the control group, although without significant differences. After intracytoplasmic sperm injection (ICSI) and further culture of human oocytes, the high-quality embryo rate in the rapamycin group was significantly elevated. Overall, rapamycin improved IVM outcomes of oocytes from aged mice and older women. The specific mechanism of the positive effects of rapamycin on IVM outcomes might be reducing ROS levels, mitigating DNA damage, and promoting developmental potential.

The fatty acid composition in follicles is related to the developmental potential of oocytes up to the blastocyst stage: a single-centre cohort study

BACKGROUND

Advanced maternal age and obesity are associated with impaired female fertility. Moreover, fatty acids (FA) in follicular fluid (FF) play important roles in oocyte maturation and embryo development. However, the effects of body mass index (BMI), age, and FF FA composition on embryo development between days 3 and 5 and blastocyst stage on day 5 are still unclear.

METHODS

This study included 138 patients undergoing assisted reproductive technology (ART), which were divided into three BMI groups (18.5-24.9 kg/m² vs. 25.0-29.9 kg/m² vs. ≥ 30.0 kg/m²) and three age-related groups (20-30 years vs. 31-34 years vs. ≥ 35 years) which were compared for ART outcomes. Further, observations were divided into quartiles based on either of three parameters related to embryo outcome, i.e. (i) embryos developing between days 3 and 5 (ED3-5) and (ii) expanded blastocysts on day 5 (EB5), both expressed proportionally to the number of oocytes with two pronuclei (2PN), as well as (iii) the embryo utilization rate (EUR). Proportions of FF FA were then compared between Q1 and Q4, representing the quartile with the worst vs. the best embryo outcome, respectively. Finally, regression models were created to assess the relationships between BMI, age, FF total FA (TFA) concentration, relative proportions of specific FA and embryo outcome.

RESULTS

Patients of Q1 had higher proportions of FF C20:5n-3, C22:6n-3 and total n-3 PUFA than Q4 patients. Furthermore, Q4 patients tended to be younger than Q1 patients. Within the whole cohort, the proportion of C20:5n-3 negatively correlated with ED3-5/2PN and EUR, while EB5/2PN tended to be negatively correlated with age. Regression models within the overweight and obese group confirmed the negative relation between C20:5n-3 and ED3-5/2PN, but also indicated additional associations: C18:1n-9 and C20:4n-6 were positively associated with ED3-5/2PN and EUR, respectively while the proportion of C18:0 was negatively associated with EUR.

CONCLUSION

The proportions of n-3 PUFA, particularly C20:5n-3 and C22:6n-3 were reduced in the patients' quartile with the best embryo outcome. This group of patients was also younger. However, the embryo quality parameters of overweight/obese patients were not associated with age but were positively associated with FF C18:1n-9 and negatively with the proportions of C18:0 or C20:5n-3.

TRIAL REGISTRATION

This study' registration number was B670201627735.

Effects of letrozole co-treatment on outcomes of gonadotropin-releasing hormone antagonist cycles in POSEIDON groups 3 and 4 expected poor responders

PURPOSE

To evaluate the effects of adjuvant letrozole administration on outcomes of gonadotropin-releasing hormone (GnRH) antagonist cycles with intra-cytoplasmic sperm injection in POSEIDON groups 3 and 4 expected poor responder women.

METHODS

This study was conducted by retrospective analysis of patients with expected poor ovarian response (POSEIDON groups 3 and 4) that underwent GnRH antagonist cycles with intra-cytoplasmic sperm injection between 2010 and 2020. A total of 488 patients with letrozole co-administration and 2564 patients without any adjuvant treatment that underwent GnRH antagonist cycles within the selected period of time were included in the study.

RESULTS

Implantation rates, clinical pregnancy rates and live birth delivery rates were significantly higher in letrozole administered patients in comparison to controls among POSEIDON group 3 women (0.39 ± 0.46 vs 0.27 ± 0.40, p = 0.01; 46.1% vs 33%, p = 0.014; 42.7% vs 31.5%, p = 0.034, respectively). Mean total doses of gonadotropins required per cycle were significantly lower in letrozole administered patients among both POSEIDON groups 3 and 4 women (2864.65 ± 878.47 IU vs 3757.27 ± 1088.89 IU, p < 0.001; 3286.06 ± 770.16 IU vs 3666.48 ± 959.66 IU, p < 0.001, respectively).

CONCLUSION

Adjuvant letrozole co-administration in intra-cytoplasmic sperm injection cycles following GnRH antagonist protocol appears to improve implantation, clinical pregnancy and live birth delivery rates in women with POSEIDON group 3 expected poor ovarian response.

Natural cycles achieve better pregnancy outcomes than artificial cycles in non-PCOS women undergoing vitrified single-blastocyst transfer: a retrospective cohort study of 6840 cycles

PURPOSE

To identify the optimal method for endometrial preparation in vitrified single-blastocyst transfer (VSBT) cycles.

METHODS

This was a retrospective cohort study for non-PCOS patients who underwent VSBT cycles from March 2015 to November 2019 in an academic reproductive medical center. A total of 6840 VSBT cycles were enrolled and classified into two groups according to different endometrial preparation methods.

RESULTS

The non-PCOS patients who underwent VSBT showed a significantly higher clinical pregnancy rate (61.96% vs 56.85%, p < 0.001) and live birth rate (49.09% vs 39.86%, p < 0.001), as well as a statistically lower early miscarriage rate (12.02% vs 18.08%, p < 0.001) in the natural cycle (NC) group compared with the artificial cycle (AC) group. Multivariable analysis further confirmed that NC was associated with an increased likelihood of clinical pregnancy (adjusted odds ratio (aOR) 0.852, 95% confidence interval (CI) 0.765-0.949, p = 0.004) and live birth (aOR 0.746, 95% CI 0.669-0.832, p < 0 .001), but decreased early miscarriage occurrence (aOR 1.447, 95% CI 1.215-1.724, p < 0.001) compared to AC.

CONCLUSIONS

Our study demonstrated that non-PCOS patients could benefit from NC in vitrified blastocyst transfer. Increased clinical pregnancy rate and decreased early miscarriage rate led to a significantly higher live birth rate in NC patients compared with AC with our present protocol.

Ovulation induction regimens are associated with a higher rate of livebirth after frozen single-blastocyst transfer among women with polycystic ovary syndrome

BACKGROUND

Hormone replacement therapy (HRT) regimen was suggested to be associated with a decreased rate of livebirth and a higher risk of hypertensive disorders of pregnancy (HDP) after frozen cleavage stage embryo transfer in women with polycystic ovary syndrome (PCOS). With the dramatically increased use of elective single embryo transfer, there is great need to explore the impacts of different endometrial preparation regimens on frozen single-blastocyst transfer in women with PCOS.

METHODS

In this study, a total of 3941 women who diagnosed with PCOS and underwent single-blastocyst transfer during their first cycles of frozen embryo transfer (FET) between March 2012 and December 2020 were included. We retrospectively compared the pregnancy and neonatal outcomes after frozen single-blastocyst transfer with endometrial preparation by HRT regimen (n = 3540), ovulation induction by human menopausal gonadotropin (hMG) regimen (n = 226), and ovulation induction by letrozole regimen (n = 175).

RESULTS

After adjustment for confounders with multivariable logistic regression, the hMG regimen group [(58.4% vs. 49.6%; adjusted odds ratio (aOR): 1.43; 95% confidence interval (CI): 1.09-1.89)] and letrozole regimen group (58.9% vs. 49.6%; aOR: 1.42; 95% CI: 1.04-1.93) were associated with a higher rate of livebirth (primary outcome), compared with the group with HRT regimen. As to the secondary outcomes, the rate of pregnancy loss in the hMG regimen group (22.8% vs. 30.3%; aOR: 0.69; 95% CI: 0.48-1.00) and letrozole regimen group (16.9% vs. 30.3%; aOR: 0.48; 95% CI: 0.30-0.78) was also lower than that in the HRT regimen group. The pregnancy outcomes between the hMG regimen group and the letrozole regimen group were similar. We did not observe significant difference in the incidences of maternal and neonatal complications among these three groups.

CONCLUSION

Ovulation induction regimen with letrozole or hMG for endometrial preparation was associated with a higher livebirth rate and a lower pregnancy loss rate in frozen single-blastocyst transfer cycles among women with PCOS.

Birthweight After Frozen Embryos Formed on the Fifth Day Versus the Sixth Day: A Retrospective Analysis Including 17,127 Singleton Newborns

BACKGROUND

Transferring blastocysts frozen on day 6 (D6) may adversely affect the pregnancy rate compared with day 5 (D5). Moreover, it remains unclear whether delayed embryo transfer affects neonatal birth weight.

METHODS

A retrospective cohort study consisting of 17,127 singleton births from single frozen embryo transfer (FET) cycles, between January 2011 and January 2020, was performed including 14,166 blastocysts frozen on D5 and 2,961 on D6. The primary outcomes of this study were neonatal birth weight and incidence of small for gestational age (SGA), large for gestational age (LGA), low birth weight (LBW), and macrosomia.

RESULTS

The mean neonatal birth weight in the D5 group (3.47 ± 0.49 kg) was significantly higher compared with the D6 group (3.45 ± 0.50 kg), although the discrepancy was only 0.02 kg. Multiple linear regression analysis for birth weight between the two groups showed no statistically significant difference (β= -0.01 t= -1.218; P>0.05). Logistic regression analysis revealed that the risks of SGA (OR 1.166; 95%CI, 0.911-1.491; P>0.05), LGA (OR 0.917; 95%CI, 0.831-1.012; P>0.05), LBW (OR 1.192; 95%CI, 0.926-1.533; P>0.05), and macrosomia (OR 0.975; 95%CI, 0.864-1.100; P>0.05) were similar in the two groups after adjusting for confounders.

CONCLUSIONS

In the FET cycle, the neonatal birth weight and incidence of LGA, SGA, LBW, or macrosomia were similar between the D5 and D6 groups, suggesting that delayed blastocyst transfer would not affect the neonatal birth weight.

A comparative study of post-warming survival rates and clinical outcomes of human blastocysts vitrified/warmed by CryoTouch and Cryotop methods

OBJECTIVE

Advances in embryo culture conditions and the development of vitrification as a revolutionary cryopreservation method have allowed for routine use of blastocyst transfer in assisted reproduction technology (ART) cycles. Several vitrification/warming media and devices have been introduced for commercial use so far. The aim of this retrospective study was to compare post-warming survival rates and clinical outcomes of human blastocysts vitrified/warmed by two different commercial methods (CryoTouch and Cryotop) during ART cycles.

METHODS

This retrospective study assessed a total of 50 frozen embryo transfer (FET) cycles conducted on 56 warmed blastocysts between January 2018 and December 2020. Post-warming blastocyst survival rates and clinical outcomes including clinical pregnancy and live birth rates were calculated after single blastocyst transfer cycles.

RESULTS

The results revealed no significant differences between two groups in post-warming survival rate (p-value=0.8381), clinical pregnancy rate (p-value=0.8157) and live birth rate (p-value=0.7041).

CONCLUSIONS

Post-warming survival rates and clinical outcomes were comparable with no significant difference in blastocysts vitrified/warmed by CryoTouch and Cryotop commercial methods.