Comparison of pregnancy outcomes following fresh and electively frozen single blastocyst transfer in natural cycle and clomiphene-stimulated IVF cycles

Is the Human Chorionic Gonadotropin Level on Day 10 After Cleaved Embryo Transfer a Predictor of Perinatal Outcome?: A Retrospective Cohort Study

This study aimed to determine whether human chorionic gonadotropin (hCG) levels at day 10 after day 2 cleaved embryo transfer can predict pregnancy and perinatal outcomes. Patients who underwent oocyte retrieval with minimal stimulation or natural cycles and fresh or vitrified-warmed transfer of a single, day 2 cleaved embryo at our clinic between November 2018 and December 2020 were included in this study. Patients were classified into four age groups for oocyte retrieval and into ten groups based on the hCG level on day 10 after embryo transfer; pregnancy complications and delivery and neonatal outcomes were examined. Of the 5,840 cycles, 3,722 (63.7%) and 2,118 (36.3%) were fresh-cleaved and vitrified-warmed embryo transfers, respectively. The mean hCG level was 24.8 mIU/mL and the clinical pregnancy and live birth rates per transfer were 29.6% and 23.4%, respectively. Maternal age at the time of oocyte retrieval, husband's age, treatment cycle, embryo type and grade, cell number, and hCG levels were correlated with pregnancy and delivery outcomes in the univariate analysis. Conversely, only maternal age and hCG levels were correlated with the outcomes in the multivariate analysis. hCG levels on day 10 post-transfer are a useful predictor of pregnancy and delivery outcomes after cleaved embryo transfer. Live birth rates vary with maternal age, even when hCG levels are the same, but they do not vary according to the treatment cycle or type of embryo transferred. Low hCG levels may be associated with vasa previa but did not affect delivery outcomes.

Fatty acid supplementation during warming improves pregnancy outcomes after frozen blastocyst transfers: a propensity score-matched study

This study aimed to examine the viability of human blastocysts after warming with fatty acids (FAs) using an in vitro outgrowth model and to assess pregnancy outcomes after a single vitrified-warmed blastocyst transfer (SVBT). For the experimental study, we used 446 discarded vitrified human blastocysts donated for research purposes by consenting couples. The blastocysts were warmed using FA-supplemented (FA group) or non-FA-supplemented (control group) solutions. The outgrowth area was significantly larger in the FA group (P = 0.0428), despite comparable blastocyst adhesion rates between the groups. Furthermore, the incidence of outgrowth degeneration was significantly lower in the FA group than in the control group (P = 0.0158). For the clinical study, we retrospectively analyzed the treatment records of women who underwent SVBT in natural cycles between January and August 2022. Multiple covariates that affected the outcomes were used for propensity score matching as follows: 1342 patients in the FA group were matched to 2316 patients in the control group. Pregnancy outcomes were compared between the groups. The rates of implantation, clinical pregnancy, and ongoing pregnancy significantly increased in the FA group after SVBTs (P = 0.0091-0.0266). These results indicate that warming solutions supplemented with FAs improve blastocyst outgrowth and pregnancy outcomes after SVBTs.

Clinical and neonatal outcomes of complete zona pellucida removal by laser-assisted hatching after single vitrified-warmed blastocyst transfer

Laser-assisted hatching (LAH) is a widely used and unavoidable technique in assisted reproductive technology after frozen embryo transfer (FET). We aimed to investigate the safety and efficacy of completely ZP (zona pellucida) removed by an assisted laser group compared to an intact group after FET. This retrospective study involved 320 SVBT  single vitrified-warmed blastocyst transfers of 213 patients who underwent clomiphene citrate (CC) based minimal stimulation protocol. This study compared 160 SVBT with ZP that were completely removed using laser-assisted (laser beams of 10-15, a wavelength of 1.48 μm, and duration of 1.8-2.2 ms) to 160 cases of intact SVBT. Fisher's exact test, chi-squared test, and logistic regression are used for statistical analysis. The women's age, cause of infertility, BMI, transferred embryo day, insemination methods, and blastocyst grade were not significantly different between two groups. The implantation rate (66.2% vs. 51.2%, P < 0.01), the clinical pregnancy rate (CPR, 52.5% vs. 39.3%, P = 0.01), and the live birth rate (LBR, 43.7% vs. 29.3%, P < 0.01) were significantly higher in the completely ZP removed than the intact group. In logistic regression analysis, the laser-assisted hatching group showed about 2 times higher implantation rate and CPR and LBR than the control group. But miscarriage, gestational weeks, gender, birth weight, and twin births were insignificant between two groups. Our study suggests ZP free embryo transfer by assisted laser is more effective and safer than intact embryo transfer.

Comparison of 1-year cumulative live birth and perinatal outcomes following single blastocyst transfer with or without preimplantation genetic testing for aneuploidy: a propensity score-matched study

PURPOSE

We evaluated whether preimplantation genetic testing for aneuploidy (PGT-A) could increase the cumulative live birth rate (CLBR) in patients with recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL).

METHODS

The clinical records of 7,668 patients who underwent oocyte retrieval (OR) with or without PGT-A were reviewed for 365 days and retrospectively analyzed. Using propensity score matching, 579 patients in the PGT-A group were matched one-to-one with 7,089 patients in the non-PGT-A (control) group. Their pregnancy and perinatal outcomes and CLBRs were statistically compared.

RESULTS

The live birth rate per single vitrified-warmed blastocyst transfers (SVBTs) significantly improved in the PGT-A group in all age groups (P < 0.0002, all). Obstetric and perinatal outcomes were comparable between both groups regarding both RIF and RPL cases. Cox regression analysis demonstrated that in the RIF cases, the risk ratio per OR was significantly lower in the PGT-A group than in the control group (P = 0.0480), particularly in women aged < 40 years (P = 0.0364). However, the ratio was comparable between the groups in RPL cases. The risk ratio per treatment period was improved in the PGT-A group in both RIF and RPL cases only in women aged 40-42 years (P = 0.0234 and P = 0.0084, respectively).

CONCLUSION

Increased CLBR per treatment period was detected only in women aged 40-42 years in both RIF and RPL cases, suggesting that PGT-A is inappropriate to improve CLBR per treatment period in all RIF and RPL cases.

The destinies of human embryos reaching blastocyst stage between Day 4 and Day 7 diverge as early as fertilization

STUDY QUESTION

What clinical and laboratory differences emerge from parallel direct comparison of embryos reaching the blastocyst stage between Days 4, 5, 6, and 7 (Days 4-7)?

SUMMARY ANSWER

Increasing times to blastocyst formation are associated with a worse clinical outcome and perturbations in developmental patterns appear as early as the fertilization stage.

WHAT IS KNOWN ALREADY

Previous evidence indicates that later times to blastocyst development are associated with a worse clinical outcome. However, the vast majority of these data concern Day 5 and Day 6 blastocysts, while Day 4 and Day 7 blastocysts remain less thoroughly investigated. In addition, studies comparing in parallel the developmental patterns and trajectories of Day 4-7 blastocysts are lacking. This leaves unanswered the question of when and how differences among such embryos emerge. Acquisition of such knowledge would significantly contribute to understanding the relative impact of intrinsic and extrinsic causes of embryo developmental kinetics and competence.

STUDY DESIGN, SIZE, DURATION

This retrospective study involved time-lapse technology (TLT) monitoring of Day 4 (N = 70), Day 5 (N = 6147), Day 6 (N = 3243), and Day 7 (N = 149) blastocysts generated in 9450 ICSI cycles. Oocyte retrievals were carried out after clomiphene citrate-based minimal ovarian stimulation, between January 2020 and April 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Couples included in the study presented with different diagnoses, mainly male factor and unexplained infertility. Cases involving cryopreserved gametes or surgically retrieved sperm were excluded. Microinjected oocytes were assessed by a combined TLT-culture system. Day 4-7 blastocyst groups were compared in terms of morphokinetics (pronuclear dynamics, cleavage patterns and timings, and embryo quality) and clinical outcome. Clinically usable blastocysts were cryopreserved and transferred in single vitrified-warmed blastocyst transfers (SVBT).

MAIN RESULTS AND THE ROLE OF CHANCE

From 19 846 microinjected oocytes, 17 144 zygotes (86.4%) were obtained. Overall, the blastocyst development rate was 56.0%. Rates of blastocysts formation on Days 4, 5, 6, and 7 were 0.7%, 64.0%, 33.8%, and 1.6%, respectively. The average expanded blastocyst development times were 98.4 ± 0.4, 112.4 ± 0.1, 131.6 ± 0.1, and 151.2 ± 0.5 h in the Day 4-7 groups, respectively. Female age was positively associated with longer times to blastocyst development. Rates of both inner cell mass (ICM) and trophectoderm (TE) morphological grade A blastocysts were negatively associated with the day of blastocyst development (P < 0.0001). The differences in development times and intervals increased progressively until blastocyst expansion (P < 0.0001 for all development times). Strikingly, such differences were already markedly evident as early as the time of pronuclear fading (tPNf) (20.6 ± 0.3, 22.5 ± 0.0, 24.0 ± 0.0, 25.5 ± 0.3; Days 4-7, respectively; P < 0.0001). Rates of cleavage anomalies (tri-/multi-chotomous mitosis or rapid cleavage) occurring at the first or second/third division cycles were also positively associated with longer times to blastocyst development. Implantation, ongoing pregnancy, and live birth rates were progressively reduced with increasing blastocyst development times (P < 0.0001), even after stratification for maternal age. When controlled for female age, male age, number of previous embryo transfer cycles, morphological grade of the ICM and TE, and progesterone supplementation, the probabilities of implantation, clinical, and ongoing pregnancy and live birth were significantly decreased in Day 6 blastocysts in comparison to Day 5 blastocysts. Follow-up data on birth length, weight, and malformations were comparable among the four blastocyst groups.

LIMITATIONS, REASONS FOR CAUTION

The study is limited by its retrospective design. Having been obtained from a single centre, the data require independent validation.

WIDER IMPLICATIONS OF THE FINDINGS

This study extends previous data on the relation between time of blastocyst formation and clinical outcome. It also indicates that differences in developmental times and patterns of Day 4-7 blastocysts occur as early as the fertilization stage, possibly dictated by intrinsic gamete-derived factors.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the participating institutions. The authors have no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

The clinical value of progestin-primed ovarian stimulation protocol for women with diminished ovarian reserve undergoing IVF/ICSI: a systematic review and meta-analysis

Background

To determine whether progestin-primed ovarian stimulation (PPOS) is more effective for women with diminished ovarian reserve (DOR) than clomiphene citrate (CC)/letrozole (LE) plus gonadotropin in IVF or ICSI treatment.

Methods

Nine databases were searched until May 24, 2023, to identify relevant studies. Forest plots were used to present the results of this meta-analysis. Begg's and Egger's tests were applied to estimate publication bias. Subgroup and sensitivity analysis were performed to check the potential sources of heterogeneity and verify the robustness of the pooled results, respectively.

Results

A total of 14 studies with 4182 participants were included for meta-analysis. There was evidence of a statistically notable increase in clinical pregnancy rate (OR = 1.39, 95%CI [1.01, 1.91], p = 0.05), optimal embryos rate (OR = 1.50, 95%CI [1.20, 1.88], p = 0.0004), and cumulative pregnancy rate (OR = 1.73, 95%CI [1.14, 2.60], p = 0.009), the duration and the amount of gonadotropin required (MD = 1.56, 95%CI [0.47, 2.66], p = 0.005; SMD = 1.51, 95%CI [0.90, 2.12], p < 0.00001), along with decrease cycle cancellation rate (OR = 0.78, 95%CI [0.64, 0.95], p = 0.02), luteinizing hormone (LH) level on the day of hCG (SMD = -0.81, 95%CI [-1.10, -0.53], p < 0.00001), and premature LH surge rate (OR = 0.10, 95%CI [0.07, 0.15], p < 0.00001) when PPOS was used. No evidence for publication bias within results was revealed.

Conclusions

Based on evidence-based results, PPOS protocol seems to improve IVF/ICSI outcomes for women with DOR. More research with larger sample sizes and rigorous designs are required to further explore the value of PPOS among women diagnosed with DOR.

Systematic review registration

www.crd.york.ac.uk, identifier CRD42023430202.

Effects of controlled ovarian stimulation regimens on top-quality blastocyst development and perinatal outcomes with the freeze-all strategy: A retrospective comparative study

OBJECTIVE

This study aimed to determine the effect of ovarian stimulation regimens on the top-quality blastocyst development rate and perinatal outcomes with the freeze-all strategy.

METHODS

A retrospective comparative cohort analysis of 149 in vitro fertilization (IVF) cycles using the freeze-all strategy was conducted. The IVF cycles were stimulated with either a gonadotropin-releasing hormone antagonist or clomiphene citrate along with gonadotropin based on the patient's serum anti-Müllerian hormone level. Oocyte retrieval, fertilization, and embryo culture were performed following standard procedures. All good-quality blastocysts were cryopreserved and used for frozen-thawed embryo transfer (FET) in subsequent cycles. The fertilization, blastulation, and top-quality blastocyst development rates were calculated. The perinatal outcomes of FET cycles, gestational period, and birth weight were assessed.

RESULTS

The main outcome of this study was the top-quality blastocyst development rate, and the secondary outcomes were perinatal parameters (e.g., gestational period and birth weight) between the stimulation regimens. Despite the higher number of usable-quality embryos in the antagonist group, the blastocyst development rate remained comparable (p=0.105). Similarly, perinatal outcomes were comparable in subsequent FET cycles (p=0.538).

CONCLUSION

These findings suggest that the choice between antagonist and clomiphene citrate with gonadotropin as stimulation in controlled ovarian stimulation regimens may not affect the top-quality blastocyst development rate. The IVF outcomes (e.g., clinical pregnancy, miscarriage, and live birth rates) remained unaffected in subsequent FET cycles. Unlike fresh embryo transfer, the birth weight and gestational length were not associated with prior controlled ovarian stimulation regimens when the freeze-all strategy was used.

Recent clomiphene citrate exposure does not impact subsequent clinical outcomes in single euploid frozen embryo transfer cycles

STUDY QUESTION

Do infertile couples who recently utilized clomiphene citrate (CC) for ovulation induction or ovarian stimulation (<90 days previously) followed by a single euploid embryo transfer (SEET) have lower implantation potential compared with patients who were not exposed to CC within 90 days before embryo transfer (ET)?

SUMMARY ANSWER

There does not appear to be an association between recent CC exposure and lower implantation potential in patients who undergo a frozen embryo transfer (FET) of euploid embryos.

WHAT IS KNOWN ALREADY

Clomiphene has been found to be associated with lower pregnancy rates when compared against other ovarian stimulation medications. The majority of published research about the effects of CC on implantation potential suggest an anti-estrogenic effect on the endometrium. Quality evidence and information about utilization of CC and its effect on implantation potential after euploid ETs is lacking in the literature.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study with propensity score matching was carried out. We included all patients that underwent an autologous SEET from September 2016 to September 2022 at a single academic-private ART center.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study group included patients that had utilized CC during either ovulation induction cycles and/or controlled ovarian stimulation at least 90 days before FET. A propensity score-matched control group of patients that were unexposed to CC within 90 days prior to SEET was used for comparisons. The primary outcome was positive pregnancy test (defined as a positive serum β-hCG measured 9 days after ET), with other outcomes including clinical pregnancy, ongoing pregnancy, biochemical pregnancy loss, and clinical pregnancy loss rates per SEET. Multivariate regression analyses fitted with generalized estimating equations were utilized to analyze if there was an association between CC utilization and IVF outcomes. Furthermore, the study evaluated the cumulative effect of CC and endometrial receptivity in vivo and subsequent IVF outcomes.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 593 patients with utilization of CC in <90 days before ET were compared with 1779 matched controls. Positive pregnancy test rates were comparable among the control group and the CC exposed groups, respectively (74.3% versus 75.7%, P = 0.79), as were clinical pregnancy (64.0% versus 65.0%, P = 0.60), ongoing pregnancy (51.8% versus 53.2%, P = 0.74), biochemical pregnancy loss (15.7% versus 14.03%, P = 0.45), and clinical pregnancy loss rates were also comparable among cohorts (17.1% versus 18.1%, P = 0.71). No association was found between utilization of clomiphene and lower implantation rates (adjusted odds ratio 0.95, 95% CI 0.76-1.18). Also, no differences were observed in sub-analyses based on multiple CC utilization periods. Finally, no association was found between the number of consecutive cumulative clomiphene cycles and sub-optimal IVF outcomes.

LIMITATIONS, REASONS FOR CAUTION

The study has inherent bias that originated from its retrospective design. Serum levels of CC were not measured and sample size for the sub-analyses was small.

WIDER IMPLICATIONS OF THE FINDINGS

There does not appear to be an association between recent CC exposure and lower implantation potential in patients who undergo a FET of euploid embryos. This finding remains consistent, even in patients who undergo multiple, consecutive clomiphene cycles prior to ET. There were no long-term effects of CC on endometrial development and clinical characteristics examined in this study. Patients that utilized CC medication prior to a SEET cycle for either ovarian stimulation or ovulation induction, can be assured that there is no evidence of a residual effect of recent CC administration that could jeopardize their pregnancy probability.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was received for the realization of this study. A.C. is advisor and/or board member of Sema4 (stakeholder in data) and Progyny. The other authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Low-dose clomiphene citrate does not reduce implantation and live birth rates in otherwise unstimulated modified natural cycle IVF-retrospective cohort study

RESEARCH QUESTION

Does antioestrogen effect of clomiphene citrate (CC) on the endometrium reduce implantation and thereby decrease pregnancy and live birth rate per transferred embryo?

METHODS

In this cohort, unstimulated IVF cycles modified with clomiphene citrate (CC-NC-IVF) and unstimulated, natural IVF cycles (NC-IVF) conducted between 2011 and 2016 were included. CC was applied in a dosage of 25mcg per day, starting on cycle day 7 until ovulation trigger day. Primary outcomes were clinical pregnancy rate, defined as amniotic sac visible in ultrasound, and live birth rate per transferred embryo. Miscarriage rate calculated as amniotic sac not ending in a live birth was secondary outcome. A modified mixed-effect Poisson regression model was applied, and adjustments were made for female age, parity, type and cause of infertility. Additionally, stratification by parity and age was performed.

RESULTS

Four hundred and ninety-nine couples underwent a total of 1042 IVF cycles, 453 being NC-IVF and 589 being CC-NC-IVF cycles. Baseline characteristics of both groups did not differ. Addition of CC did neither decrease clinical pregnancy rate (aRR 0.86; 95% CI 0.67-1.12) nor live birth rate per transferred embryo (aRR 0.84; 95% CI 0.62-1.13) in comparison with NC-IVF. Miscarriage rate did not differ between CC-NC-IVF and NC-IVF (aRR 0.95; 95% CI 0.57-1.57).

CONCLUSION

Low-dose CC does not reduce pregnancy or live birth rate per transferred embryo. It can be used in infertility treatment without negatively affecting the endometrium and implantation.

Preimplantation Genetic Testing for Aneuploidy for Recurrent Pregnancy Loss and Recurrent Implantation Failure in Minimal Ovarian Stimulation Cycle for Women Aged 35-42 Years: Live Birth Rate, Developmental Follow-up of Children, and Embryo Ranking

This study was aimed at exploring the benefits of preimplantation genetic testing for aneuploidy (PGT-A) in ensuring a successful pregnancy in patients with recurrent pregnancy loss (RPL) caused by an abnormal number of chromosomes in the embryo and recurrent implantation failure (RIF). Thirty-two patients who underwent PGT-A (18 in the RIF protocol and 14 in the RPL protocol) were enrolled in the study, and 2556 patients who did not undergo PGT-A during the same in vitro fertilization (IVF) treatment period were enrolled as controls. All patients underwent minimal stimulation cycle IVF. In the RPL protocol, the live birth rate per embryo transfer (ET) and that per patient were higher with PGT-A (80.0% each) than without it (0% each; P = 0.0050), and the rate of miscarriages was lower with PGT-A than without it (20.0% vs. 100.0%, P = 0.0098). In the RIF protocol, there were no significant differences in the live birth rate per ET and in the rate of miscarriages between groups with and without PGT-A-90.0% vs. 69.2% (P = 0.2313) and 0% vs. 10.0% (P = 0.3297), respectively. None of the children whose mothers underwent PGT-A presented adverse findings at a 1.5-year developmental check-up. In conclusion, PGT-A in RPL is advantageous for improving the live birth rate per ET and that per patient in minimal stimulation cycle IVF; it reduces the rate of miscarriages. In addition, PGT-A might be more beneficial for embryo selection than the existing morphological grades of blastocysts, resulting in earlier conception.

Maternal age affects pronuclear and chromatin dynamics, morula compaction and cell polarity, and blastulation of human embryos

STUDY QUESTION

Does maternal ageing impact early and late morphokinetic and cellular processes of human blastocyst formation?

SUMMARY ANSWER

Maternal ageing significantly affects pronuclear size and intra- and extra-nuclear dynamics during fertilization, dysregulates cell polarity during compaction, and reduces blastocoel expansion.

WHAT IS KNOWN ALREADY

In ART, advanced maternal age (AMA) affects oocyte yield, fertilization, and overall developmental competence. However, with the exception of chromosome segregation errors occurring during oocyte meiosis, the molecular and biochemical mechanisms responsible for AMA-related subfertility and reduced embryo developmental competence remain unclear. In particular, studies reporting morphokinetics and cellular alterations during the fertilization and pre-implantation period in women of AMA remain limited.

STUDY DESIGN, SIZE, DURATION

A total of 2058 fertilized oocytes were stratified by maternal age according to the Society for Assisted Reproductive Technology classification (<35, 35-37, 38-40, 41-42, and >42 years) and retrospectively analysed. AMA effects were assessed in relation to: embryo morphokinetics and morphological alterations; and the presence and distribution of cell polarity markers-Yes-associated protein (YAP) and protein kinase C-ζ (PKC-ζ)-involved in blastocyst morphogenesis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 1050 cycles from 1050 patients met the inclusion criteria and were analysed. Microinjected oocytes were assessed using a time-lapse culture system. Immature oocytes at oocyte retrieval and mature oocytes not suitable for time-lapse monitoring, owing to an excess of residual corona cells or inadequate orientation for correct observation, were not analysed. Phenomena relevant to meiotic resumption, pronuclear dynamics, cytoplasmic/cortical modifications, cleavage patterns and embryo quality were annotated and compared among groups. Furthermore, 20 human embryos donated for research by consenting couples were used for immunofluorescence.

MAIN RESULTS AND THE ROLE OF CHANCE

Static microscopic observation revealed that blastocyst formation and expansion were impaired in the 41-42 and >42-year groups (P < 0.0001). The morphological grades of the inner cell mass and trophectoderm were poorer in the >42-year group than those in the <35-year group (P = 0.0022 and P < 0.0001, respectively). Time-lapse microscopic observation revealed a reduction in nucleolus precursor body alignment in female pronuclei in the 41-42 and >42-year groups (P = 0.0010). Female pronuclear area decreased and asynchronous pronuclear breakdown increased in the >42-year group (P = 0.0027 and P < 0.0122, respectively). Developmental speed at cleavage stage, incidence of irregularity of first cleavage, type and duration of blastomere movement, and number of multinucleated cells were comparable among age groups. Delayed embryonic compaction and an increased number of extruded blastomeres were observed in the >42-year group (P = 0.0002 and P = 0.0047, respectively). Blastulation and blastocyst expansion were also delayed in the 41-42 and >42-year groups (P < 0.0001 for both). YAP positivity rate in the outer cells of morulae and embryo PKC-ζ immunoflourescence decreased in the >42-year group (P < 0.0001 for both).

LIMITATIONS, REASONS FOR CAUTION

At the cellular level, the investigation was limited to cell polarity markers. Cell components of other developmental pathways should be studied in relation to AMA.

WIDER IMPLICATIONS OF THE FINDINGS

The study indicates that maternal ageing affects the key functions of embryo morphogenesis, irrespective of the well-established influence on the fidelity of oocyte meiosis.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the participating institutions. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Association between endometrial thickness before ovulation, live birth, and placenta previa rates in clomiphene citrate-treated cycles

BACKGROUND

Although a recent study reported that the pregnancy outcomes in the first trimester were more correlated with endometrial thickness on the day of the trigger than with endometrial thickness on the day of single fresh-cleaved embryo transfer, it remains unclear whether endometrial thickness on the day of the trigger can predict live birth rate after a single fresh-cleaved embryo transfer.

OBJECTIVE

This study aimed to examine whether endometrial thickness on the trigger day is associated with live birth rates and whether modifying the single fresh-cleaved embryo transfer criteria to reflect endometrial thickness on the trigger day improved the live birth rate and reduced maternal complications in a clomiphene citrate-based minimal stimulation cycle.

STUDY DESIGN

This was a retrospective study of the outcomes of 4440 treatment cycles of women who underwent single fresh-cleaved embryo transfer on day 2 of the retrieval cycle. From November 2018 to October 2019, single fresh-cleaved embryo transfer was performed when endometrial thickness on the day of single fresh-cleaved embryo transfer was ≥8 mm (criterion A). From November 2019 to August 2020, single fresh-cleaved embryo transfer was conducted when endometrial thickness on the day of the trigger was ≥7 mm (criterion B).

RESULTS

A multivariate logistic regression analysis revealed that increased endometrial thickness on the trigger day was significantly associated with an improvement in the live birth rate after single fresh-cleaved embryo transfer (adjusted odds ratio, 1.098; 95% confidence interval, 1.021-1.179). The live birth rate was significantly higher in the criterion B group than in the criterion A group (22.9% and 19.1%, respectively; P=.0281). Although endometrial thickness on the day of single fresh-cleaved embryo transfer was sufficient, the live birth rate tended to be lower when endometrial thickness on the trigger day was <7.0 mm than when endometrial thickness on the day of the trigger was ≥7.0 mm. The risk for placenta previa was reduced in the criterion B group when compared with the criterion A group (4.3% and 0.6%, respectively; P=.0222).

CONCLUSION

This study demonstrated an association of decreased endometrial thickness on the trigger day with low birth rate and a high incidence of placenta previa. A modification of the criteria for a single fresh-cleaved embryo transfer based on endometrial thickness may improve pregnancy and maternal outcomes.

Letrozole-induced endometrial preparation improved the pregnancy outcomes after frozen blastocyst transfer compared to the natural cycle: a retrospective cohort study

Background

Letrozole treatment is considered an effective option in endometrial preparation for frozen embryo transfers in patients with ovulation disorders or irregular menstruation; however, the effectiveness of letrozole-induced endometrial preparation remains unclear in ovulatory patients. Furthermore, there is no comparative study reporting on pregnancy complications and congenital anomalies after frozen embryo transfers comparing natural and letrozole-assisted cycles. This study examined whether letrozole-induced endometrial preparation affected pregnancy outcomes, perinatal outcomes, and congenital anomalies after single vitrified-warmed blastocyst transfers (SVBTs) in ovulatory patients, as compared with the natural cycle.

Methods

This historic cohort study included only patients with unexplained infertility. Overall, 14,611 patients who underwent SVBTs between July 2015 and June 2020, comprising both natural and letrozole-assisted cycles, were included. Multiple covariates that impact outcomes were used for propensity score matching; 1,911 patients in the letrozole group were matched to 12,700 patients in the natural group, and the clinical records of 1,910 patients in each group were retrospectively analysed. Cycle characteristics, pregnancy outcomes (clinical pregnancy, ongoing pregnancy, and live birth), and incidence of pregnancy complications and congenital anomalies were statistically compared between the two groups.

Results

Multivariate logistic regression analysis showed that letrozole administration during SVBT cycles significantly improved the live birth rate (P = 0.0355). Gestational age, birth length, birth weight, and infant sex, as well as the incidence of pregnancy complications and birth defects, were statistically comparable between the two groups. Furthermore, multivariate logistic regression analysis revealed that the perinatal outcomes were not affected by letrozole-induced endometrial preparation.

Conclusions

Letrozole-induced endometrial preparation improved the live birth rate compared with the natural cycle, without adverse effects on perinatal outcomes and congenital anomalies after SVBTs. Therefore, letrozole-induced endometrial preparation might be a safe and more effective strategy, especially for patients with insufficient luteal function.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-05174-0.

Human 1PN and 3PN zygotes recapitulate all morphokinetic events of normal fertilization but reveal novel developmental errors

STUDY QUESTION

Does mono- (1PN) and tri-pronuclear (3PN) fertilization recapitulate the morphokinetic changes of normal bi-pronuclear (2PN) fertilization?

SUMMARY ANSWER

Abnormal fertilization retraces the overall choreography of normal fertilization but reveals novel morphokinetic phenomena and raises scientifically and clinically relevant questions.

WHAT IS KNOWN ALREADY

ART has allowed the extracorporeal observation of early human development. Time-lapse technology (TLT) has revealed the complexity of the morphokinetic changes underpinning fertilization and the importance of this process for the genetic and cellular integrity of the embryo. Abnormal fertilization has remained neglected, despite its relevance to the physiology and pathology of early human development.

STUDY DESIGN, SIZE, DURATION

This retrospective study involved TLT observation of normally (2PN, N = 2517) and abnormally (1PN, N = 41; 3PN, N = 27) fertilized oocytes generated in ICSI cycles performed between October 2019 and December 2020. Oocyte retrieval was carried out after clomiphene citrate-based minimal ovarian stimulation. Oocytes of patients with different diagnoses of infertility were included in the analysis, while cases involving cryopreserved gametes or surgically retrieved sperm were excluded.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study included 1231 couples treated for diverse infertility causes. The fraction of male factor cases was substantial (36.1%). Microinjected oocytes were assessed by a combined TLT-culture system. Oocytes not suitable for TLT assessment, owing to an excess of residual corona cells or inadequate orientation for correct observation, were not analysed. Phenomena relevant to meiotic resumption, pronuclear dynamics, cytoplasmic/cortical modifications, cleavage patterns and embryo quality were annotated and compared between groups.

MAIN RESULTS AND THE ROLE OF CHANCE

Extrusion of the second polar body (PBII) was observed in almost all 2PN/1PN (99.9% and 100.0%, respectively) and in a vast majority of 3PN zygotes (92.1%). Rates of PBII fusion with the ooplasm were much higher in 1PN and 3PN zygotes (P < 0.0001 versus 2PN). The cytoplasmic wave was observed not only in 2PN and 3PN but also in 1PN zygotes (positivity rates of 99.8% and 100% and 82.9%, respectively; P < 0.0001). More rarely, 2PN and 1PN zygotes emitted a third polar body (PBIII). The average times of this event were comparable. The presence and position of the cytoplasmic halo were comparable among the three classes of zygotes. In the 1PN group, the single PN was maternally or paternally derived in 17 and 24 zygotes, respectively, while in the vast majority of 3PN zygotes (121/127) the supernumerary PN was of maternal origin. Average times of maternal PN appearance were comparable, while average times of paternal PN appearance were delayed in 3PN zygotes (P = 0.0127). Compared with the control group, the area of the maternal PN was larger in 1PN zygotes, but smaller in 3PN zygotes (P < 0.0001). The paternal PNs displayed the same trend (P < 0.0001), although such values were consistently smaller than maternal PNs. The area of the third PN in the 3PN group was on average more than 50% smaller than those of maternal and paternal PNs. In maternal PNs of 3PN zygotes, nucleolus precursor bodies (NPBs) aligned along the area of PN juxtaposition at a lower rate compared with the 2PN group. The rate of NPB alignment was ∼50% smaller in 1PN zygotes (P = 0.0001). In paternal PNs, the rates of NPB alignment were not statistically different among the three groups. Asynchronous PN breakdown was increased in 3PN compared with 2PN zygotes (P = 0.0026). In 1PN zygotes, a developmental delay was observed starting from the disappearance of the cytoplasmic halo, reaching 9 h at the time of the first cleavage (P < 0.0001). Higher rates of abnormal cleavage patterns and blastomere fragmentation (P < 0.0001) were observed in 1PN compared to 2N and 3PN zygotes. Cleavage progression was increasingly affected after abnormal fertilization, especially 1PN, finally resulting in blastocyst formation rates of 70.2%, 12.2% and 53.5% in 2PN, 1PN and 3PN embryos, respectively (P < 0.0001). Both maternal and paternal ages were higher in cases involving 3PN fertilization.

LIMITATIONS, REASONS FOR CAUTION

The study data were obtained from ICSI, but not standard IVF, treatments carried out in a single centre. The study findings therefore require independent verification.

WIDER IMPLICATIONS OF THE FINDINGS

This study reports the first detailed morphokinetic map of human abnormal fertilization. Collectively, this evidence prompts new scientific hypotheses and raises clinical questions relevant to the aetiology and the treatment of abnormal fertilization.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the participating institutions. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Correlation between an annotation-free embryo scoring system based on deep learning and live birth/neonatal outcomes after single vitrified-warmed blastocyst transfer: a single-centre, large-cohort retrospective study

Propose

Does an annotation-free embryo scoring system based on deep learning and time-lapse sequence images correlate with live birth (LB) and neonatal outcomes?

Methods

Patients who underwent SVBT cycles (3010 cycles, mean age: 39.3 ± 4.0). Scores were calculated using the iDAScore software module in the Vitrolife Technology Hub (Vitrolife, Gothenburg, Sweden). The correlation between iDAScore, LB rates, and total miscarriage (TM), including 1st- and 2nd-trimester miscarriage, was analysed using a trend test and multivariable logistic regression analysis. Furthermore, the correlation between the iDAScore and neonatal outcomes was analysed.

Results

LB rates decreased as iDAScore decreased (P < 0.05), and a similar inverse trend was observed for the TM rates. Additionally, multivariate logistic regression analysis showed that iDAScore significantly correlated with increased LB (adjusted odds ratio: 1.811, 95% CI: 1.666–1.976, P < 0.05) and decreased TM (adjusted odds ratio: 0.799, 95% CI: 0.706–0.905, P < 0.05). There was no significant correlation between iDAScore and neonatal outcomes, including congenital malformations, sex, gestational age, and birth weight. Multivariate logistic regression analysis, which included maternal and paternal age, maternal body mass index, parity, smoking, and presence or absence of caesarean section as confounding factors, revealed no significant difference in any neonatal characteristics.

Conclusion

Automatic embryo scoring using iDAScore correlates with decreased miscarriage and increased LB and has no correlation with neonatal outcomes.

Supplementary information

The online version contains supplementary material available at 10.1007/s10815-022-02562-5.

Maternal and obstetric outcomes are influenced by developmental stage and cryopreservation of transferred embryos after clomiphene citrate-based minimal stimulation IVF

STUDY QUESTION

Is the embryo transfer (ET) method associated with maternal and perinatal outcomes after minimal stimulation IVF using clomiphene citrate (CC)?

SUMMARY ANSWER

The incidence of pregnancy complications and adverse perinatal outcomes was influenced by the developmental stage (cleavage versus blastocyst stages) and cryopreservation (fresh versus vitrified) of the transferred embryos.

WHAT IS KNOWN ALREADY

Pregnancies resulting from IVF are associated with higher risks of adverse perinatal outcomes compared to natural conceptions; therefore, the next focus in reproductive medicine should be to assess whether these increased risks are attributable to IVF. Pregnancy complications and perinatal outcomes should be considered in addition to pregnancy outcomes when selecting the ET method, however, studies that describe the influence of transfer methods on perinatal and maternal outcomes are limited.

STUDY DESIGN, SIZE, DURATION

This study retrospectively analysed a large single-centre cohort. The clinical records of 36 827 women who underwent oocyte retrieval (during a CC-based minimal stimulation cycle) followed by their first ET at the fertility treatment centre between January 2008 and December 2017 were retrospectively analysed. The patients underwent a single fresh cleavage-stage ET (SFCT), single vitrified-warmed cleavage-stage ET (SVCT) or single vitrified-warmed blastocyst transfer (SVBT). This study only included one cycle per patient.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Oocyte retrieval was performed following CC-based minimal ovarian stimulation. The embryos were transferred 2–3 days after retrieval or vitrified at the cleavage or blastocyst stage. The vitrified embryos were then warmed and transferred within the natural cycles. Pregnancy complications and perinatal outcomes were stratified according to the transfer methods used. Multivariate logistic regression analysis was performed to evaluate the effect of ET methods on the prevalence of pregnancy complications and congenital anomalies.

MAIN RESULTS AND THE ROLE OF CHANCE

The rates of clinical pregnancy and delivery were significantly different among the groups. We analysed pregnancy complications in 7502 singleton births (SFCT, 3395 cycles; SVCT, 586 cycles; and SVBT, 3521 cycles). Multivariate logistic regression analysis revealed that the adjusted odds ratio (AOR) for hypertensive disorders in pregnancy was significantly lower in the SVBT group than in the SFCT group [AOR, 0.72; 95% CI, 0.56–0.92]. The AOR for low-lying placenta was lower in the SVBT group than in the SFCT group (AOR, 0.34; 95% CI, 0.19–0.60). The AOR for placenta previa was lower in the SVCT and SVBT groups than in the SFCT group (AOR, 0.21; 95% CI, 0.07–0.58 versus AOR, 0.53; 95% CI, 0.38–0.75, respectively). A total of 7460 follow-up data on neonatal outcomes was analysed. The AOR for preterm delivery was lower in the SVBT group than in the SFCT group (AOR, 0.78; 95% CI, 0.64–0.94). The AOR for low birthweight was significantly lower after SVCT and SVBT than after SFCT (AOR, 0.68; 95% CI, 0.46–0.98 versus AOR, 0.57; 95% CI, 0.48–0.66, respectively). The AOR for small for gestational age was lower in the SVCT and SVBT groups than in the SFCT group (AOR, 0.68; 95% CI, 0.46–0.98 versus AOR, 0.44; 95% CI, 0.36–0.55, respectively). The AOR for large for gestational age babies was higher in the SVBT group than in the SFCT group (AOR, 1.88; 95% CI, 1.62–2.18). The incidence of each congenital anomaly was similar among the groups.

LIMITATIONS, REASONS FOR CAUTION

The study data were collected through self-reported parental questionnaires on maternal and neonatal outcomes. Our findings were not compared with the incidence of pregnancy complications and congenital anomalies in natural pregnancies. Furthermore, this study was retrospective in nature; therefore, further studies are required to ascertain the generalizability of these findings to other clinics with different protocols and/or different patient demographics.

WIDER IMPLICATIONS OF THE FINDINGS

This study demonstrated reassuring outcomes for SVBT (in terms of a lower incidence of pregnancy complications) compared to SFCT. Our findings provide valuable knowledge that will help improve perinatal and maternal outcomes in CC-based stimulation and inform couples of the possible benefits and risks of each type of ET method.

STUDY FUNDING/COMPETING INTEREST(S)

This research did not receive any specific grants from funding agencies in the public, commercial, or not-for-profit sectors. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Wisdom of Freezing All Valuable Embryos

Background: It is controversial whether that “Freeze-only” strategy is superior to Fresh embryo transfer in ART patients with normal ovarian response. There are two reasons supporting a “Freeze-only” strategy. One is that frozen-thawed embryos are transferred to a more physiologically receptive endometrium. While fresh embryos are transferred to a badly affected one because of controlled-ovarian stimulations, which cause the discordant development of the endometrium, when thawed-frozen embryos are transferred in a subsequent cycle the endometrium is not affected by high estrogen levels. The other reason is the big difference in cryopreservation and stimulation techniques.

Methods: We investigated the annual ART reports in Japan from 1992 to 2018, and our clinical outcomes of frozen-thawed embryo transfers and fresh embryo transfers from 2015 to 2019. This enabled the assessment of the survival rate of frozen blastocyst by Cryotop safety kit after thawing in four different clinics. We compared the outcomes of frozen embryo transfer (FroET) to fresh embryo transfer.

Results: The proportion of birth in Japan in the study interval found that FroET was responsible for 86.7% of births, compared to 13.3% of births resulting from fresh embryo transfers after IVF or intracytoplasmic sperm injection (ICSI). Clinical outcome of FroET in our clinic was significantly higher than that of fresh embryo transfer regardless of maternal age and number of collected oocytes. Average survival rate of frozen blastocyst by Cryotop safety kit after thawing in four clinics was over 95%.

Conclusions: We believe that “Freeze-only high-quality blastocysts” is superior to fresh embryo transfer in terms of clinical outcome, at least when compared to historical results.

Optimal individualization of patient-oriented ovarian stimulation in Japanese assisted reproductive technology clinics, a review for unique setting with advanced-age patients

Ovarian stimulation is a key issue in assisted reproductive technology (ART) treatment. ART practice in Japan is unique with various types of ovarian stimulation protocols, which may contribute to lower pregnancy rates compared to other countries. This review aims to clarify optimal individualized ovarian stimulation for improving the pregnancy rate per one oocyte retrieval cycle in Japan. We performed a literature review to describe ovarian stimulation, classification of infertile women depending on ovarian reserve and response, and Japanese ART data and discussed optimal conventional and mild ovarian stimulation protocols in Japan. According to Japanese ART registry data, the live birth rate of 30-35-year-old women was 32%-37% per ET cycle; therefore, four to five embryos are calculatedly needed when aiming a cumulative live birth rate of ≥80%. Mild stimulation aimed at collecting 5-10 oocytes can be alternative choice as an optimal ovarian stimulation protocol in young women. In 40-year-old women, the live birth rate is 18.8%, resulting in eight or more embryos as necessary. Conventional stimulation must be required in women with advanced age. In poor responders, however, mild stimulation may be sufficient for maximumly extracting their ovarian function. In Japan, mild ovarian stimulation can be selected in patients with a good prognosis and poor responders; however, conventional ovarian stimulation is necessary for women in advanced age.

Redox state as assessed using the measurement of human non-mercaptalbumin in embryo culture media is associated with successful embryo development in human in vitro fertilization

The role of oxidative stress in the pathogenesis of various diseases has been attracting attention. We speculated as to whether the redox state of treatment solutions used for various diseases may play a role in treatment success. In the current study, we focused on the human embryo culture medium used for in vitro fertilization (IVF). A total of 173 oocytes from a total of 91 patients treated with IVF were enrolled. The redox state was assessed by measuring the levels of human non-mercaptalbumin (HNA). We analyzed factors related to blastocyst formation on day 5 or 6 after insemination. We also developed a random forest (RF) model for the prediction of blastocyst formation. The variable importance in the predictive model was assessed using the mean decrease in the Gini impurity. Blastocyst formation was observed in 41.04% (71/173) of the oocytes and was associated with a lower %HNA in the culture medium, a younger patient age, and the fertilization method (standard IVF or intracytoplasmic sperm injection). The RF model developed using these factors and 70% of the samples (training set, n = 121) was validated in the remaining testing set (n = 52) and produced an area under the curve of 0.761, where the %HNA in the culture medium was the most important variable for predicting blastocyst formation. In conclusion, lower levels of oxidative stress in embryo culture media were associated with the success of IVF treatment. The redox state of treatment solutions should be considered to support treatment success.

Characteristics of the cytoplasmic halo during fertilisation correlate with the live birth rate after fresh cleaved embryo transfer on day 2 in minimal ovarian stimulation cycles: a retrospective observational study

BACKGROUND

Information regarding the influence of cytoplasmic events during fertilisation on the clinical outcome remains limited. The cytoplasmic halo is one of these events. A previous study that used time-lapse technology found an association of the presence and morphokinetics of the cytoplasmic halo with cleavage patterns, development to the blastocyst stage, and the ongoing pregnancy rate after blastocyst transfer. Therefore, the cytoplasmic halo may be a useful predictor of the pregnancy outcome after cleaved embryo transfer. This study evaluated the ability of the cytoplasmic halo to predict a live birth after fresh cleaved embryo transfer on day 2, and sought to identify factors potentially influencing the presence and morphokinetics of the halo.

METHODS

A total of 902 embryos cultured in the EmbryoScope+® time-lapse system and subjected to single fresh cleaved embryo transfer were retrospectively analysed. The presence and duration of a cytoplasmic halo were annotated. The initial positions of the pronuclei were also observed. The correlation between the cytoplasmic halo and live birth was evaluated and the association of the cytoplasmic halo with patient, cycle, and embryonic characteristics was determined.

RESULTS

Absence of a cytoplasmic halo was associated with a significant decrease in the likelihood of a live birth after fresh cleaved embryo transfer. Prolongation of the halo, especially the duration of central repositioning of cytoplasmic granules, had an adverse impact on the live birth rate. The characteristics of the cytoplasmic halo were not affected by the ovarian stimulation method used, female age, the serum steroid hormone level on the day of trigger, or semen quality. However, the cytoplasmic halo was significantly affected by male age, oocyte diameter, and the initial position of the male pronucleus.

CONCLUSIONS

Absence or prolongation of the cytoplasmic halo was negatively correlated with the live birth rate after fresh cleaved embryo transfer. The characteristics of the cytoplasmic halo were strongly associated with oocyte diameter, male age, and the initial position of the male pronucleus. These findings indicate that the characteristics of the cytoplasmic halo can be used to select more competent embryos for transfer at the cleavage stage.

Perturbations of morphogenesis at the compaction stage affect blastocyst implantation and live birth rates

STUDY QUESTION

Do perturbations of embryo morphogenesis at compaction affect blastocyst development and clinical outcomes in assisted reproduction cycles?

SUMMARY ANSWER

Cell exclusion and extrusion, i.e. cell disposal occurring respectively before or during morula compaction, affect blastocyst yield and quality, as well as rates of pregnancy and live birth.

WHAT IS KNOWN ALREADY

Despite its pivotal role in morphogenesis for blastocyst organisation and cell fate determination, compaction at the morula stage has received little attention in clinical embryology. Time lapse technology (TLT) allows detailed morphokinetic analysis of this developmental stage. However, even in the vast majority of previous TLT studies, compaction was investigated without a specific focus. Recently, we reported that compaction may be affected by two clearly-distinct patterns of cell disposal, exclusion and extrusion, occurring prior to and during compaction, respectively. However, the crucial question of the specific relevance of partial compaction for embryo development and competence in ART has remained unanswered until now.

STUDY DESIGN, SIZE, DURATION

This study involved the assessment of laboratory and clinical outcomes of 2,059 morula stage embryos associated with 1,117 ICSI patients, who were treated with minimal stimulation and single vitrified-warmed blastocyst transfer (SVBT) from April 2017 to March 2018. Patterns of morula compaction were assessed and analyzed in relation to embryonic and clinical outcomes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Following ICSI, time-lapse videos were analysed to annotate morphokinetic parameters relevant to both pre- and post-compaction stages. According to their morphokinetic history, morulae were classified as: (I) fully compacted morulae (FCM); (II) partially compacted morulae (PCM), showing cells (a) excluded from the compaction process from the outset (Exc-PCM), (b) extruded from an already compacted morula (Ext-PCM), or (c) showing non-compacted cells arisen from both patterns (Exc/Ext-PCM). The number of excluded/extruded cells was also annotated. Possible correlations of compaction patterns with 13 morphokinetic parameters, abnormal cleavage, blastocyst yield and morphological grade, clinical and ongoing pregnancy rates, and live birth rate were evaluated. Other factors, such as patient and cycle characteristics, possibly associated with compaction patterns and their outcomes, were investigated.

MAIN RESULTS AND THE ROLE OF CHANCE

Full compaction was observed in 39.0% of all embryos. However, partially compacted morulae (PCM) showing excluded (Exc-PCM), extruded (Ext-PCM) cells, or indeed both phenotypes (Exc/Ext-PCM) were frequently detected (24.8%, 16.6%, and 19.6%, respectively) and collectively (61%) exceeded fully compacted morulae. Blastomere exclusion or extrusion affected one or several cells, in different proportions. In comparison to FCM, the developmental pace of the three PCM groups, observed at 13 developmental stages starting from pronuclear fading, was progressively slower (P < 0.0001). Developmental delay at post-compaction stages was more pronounced in the group showing both patterns of partial compaction. Blastomere exclusion and/or extrusion had a large negative impact on blastocyst development. In particular, rates of blastocyst formation and cryopreservation were very low in the Ext-PCM and Exc/Ext-PCM groups (P < 0.0001). Rates of blastocysts with ICM or TE of highest quality (Grade A) were severely affected in all PCM groups (P < 0.0001). In 1,083 SVBTs, blastocysts derived from all PCM groups produced much lower clinical pregnancy, ongoing pregnancy, and live birth rates (P < 0.0001). All three patterns of partial compaction emerged as factors independently associated with live birth rate, even after multivariate logistic regression analysis including maternal/paternal age, female BMI, and number of previous embryo transfers as possible confounding factors.

LIMITATIONS, REASONS FOR CAUTION

The retrospective design of the study represents a general limitation.

WIDER IMPLICATIONS OF THE FINDINGS

This large-scale study represents a further important demonstration of embryo plasticity and above all indicates new robust morphokinetic parameters for improved algorithms of embryo selection.

STUDY FUNDING/COMPETING INTEREST(S)

This study was exclusively supported by the participating institutions. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

NA.

Complementary and Alternative Medicine for the Treatment of Abnormal Endometrial Conditions in Women with PCOS: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

Endometrial lesions in patients with polycystic ovary syndrome (PCOS) exhibit complex pathological features, and these patients are at risk of both short-term and long-term complications. Complementary and alternative medicine (CAM), which is gradually becoming more accepted and is believed to be clinically effective, claims to be promising for treating PCOS, and thus its effect on the abnormal endometrium of PCOS patients should be assessed. The present meta-analysis sought to evaluate the efficacy and safety of CAM in treating endometrial lesions in patients with PCOS.

Methods

Randomized trials on CAM were identified in four Chinese and seven English-language databases from their establishment to January 2020. The present study included patients diagnosed with PCOS and abnormal endometrial conditions who underwent CAM therapy independently or in combination with traditional western medicine. Data were extracted, and the Cochrane "risk of bias" tool was used to assess methodological quality. Effects were expressed as the relative risk (RR) or mean difference (MD/SMD) with 95% confidence interval (CI) as calculated with Rev Man 5.3.

Results

A total of 13 randomized controlled trials were included, involving 1,297 PCOS patients treated for endometrial abnormalities. Methodological quality was generally unclear or had a low risk of bias. The trials tested four different types of CAM therapies (i.e., traditional Chinese medicine treatment, acupuncture treatment, traditional Chinese medicine in combination with western medicine treatment, and acupuncture in combination with western medicine treatment). CAM treatment could significantly reduce the endometrial thickness in PCOS patients compared to western medicine alone (SMD -0.88, 95% CI [-0.12, -0.57]; I ² = 64%). Compared with clomiphene treatment for the induction of ovulation, CAM treatment showed a clear improvement in endometrial thickness during ovulation (SMD 2.03, 95% CI [1.64, 2.02]; I ² = 48%). Moreover, CAM was more effective than western medicine alone in reducing the endometrial spiral artery pulsatility index. No significant difference was seen between CAM and traditional treatment when these were used to improve traditional Chinese medicine syndrome scores. Acupuncture alone or traditional Chinese medicines (taken orally) in combination with western medicine significantly increased the pregnancy rate of PCOS patients (RR 1.59, 95% CI [1.30, 1.93]; I ² = 51%, P < 0.00001), and CAM was more effective than western medicine alone for improving hormone levels. No serious adverse events were reported in 11 of the 13 trials.

Conclusions

CAM may effectively ameliorate the endometrial condition of PCOS patients, and it can regulate the level of hormone secretion to increase the ovulation rate and the pregnancy rate.

Endometrial thickness on the day of the LH surge: an effective predictor of pregnancy outcomes after modified natural cycle-frozen blastocyst transfer

STUDY QUESTION

Can the endometrial thickness (EMT) on the day of the LH surge predict pregnancy outcomes after single vitrified-warmed blastocyst transfers (SVBTs) in modified natural cycles?

SUMMARY ANSWER

Decreased EMT on the day of the LH surge is associated with older female age and a shortened proliferation phase and may be associated with low live birth and high chemical pregnancy rates.

WHAT IS KNOWN ALREADY

The relation between EMT on the day of embryo transfer (ET) and pregnancy outcomes remains controversial; although numerous studies reported an association between decreased EMT on the day of ET and a reduced likelihood of pregnancy, recent studies demonstrated that the EMT on the day of ET had limited independent prognostic value for pregnancy outcomes after IVF. The relation between EMT on the day of the LH surge and pregnancy outcomes after SVBT in modified natural cycles is currently unknown.

STUDY DESIGN, SIZE, DURATION

In total, 808 SVBTs in modified natural cycles, performed from November 2018 to October 2019, were analysed in this retrospective cohort study. Associations of EMT on the days of the LH surge with SVBT and clinical and ongoing pregnancy rates were statistically evaluated. Clinical and ongoing pregnancy rates were defined as the ultrasonographic observation of a gestational sac 3 weeks after SVBTs and the observation of a foetal heartbeat 5 weeks after SVBTs, respectively. Similarly, factors potentially associated with the EMT on day of the LH surge, such as patient and cycle characteristics, were investigated.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study includes IVF/ICSI patients aged 24–47 years, who underwent their first SVBT in the study period. After monitoring follicular development and serum hormone levels, ovulation was triggered via a nasal spray containing a GnRH agonist. After ovulation was confirmed, SVBTs were performed on Day 5. The EMT was evaluated by transvaginal ultrasonography on the day of the LH surge and immediately before the SVBT procedure.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the original 901 patients, 93 who were outliers for FSH or proliferative phase duration data were excluded from the analysis. Patients were classified according to quartiles of EMT on day of the LH surge, as follows: EMT < 8.1 mm, 8.1 mm ≤ EMT < 9.1 mm, 9.1 mm ≤ EMT < 10.6 mm and EMT ≥ 10.6 mm. Decreased EMT on day of the LH surge was associated with lower live birth (P = 0.0016) and higher chemical pregnancy (P = 0.0011) rates. Similarly, patients were classified according to quartiles of EMT on day of the SVBT, as follows: EMT < 9.1 mm, 9.1 mm ≤ EMT < 10.1 mm, 10.1 mm ≤ EMT < 12.1 mm and EMT ≥ 12.1 mm. A decreased EMT on the day of SVBT was associated with a lower live birth rate (P = 0.0095) but not chemical pregnancy rate (P = 0.1640). Additionally, multivariate logistic regression analysis revealed a significant correlation between EMT on day of the LH surge and ongoing pregnancy; however, no correlation was observed between EMT on the day of SVBT and ongoing pregnancy (adjusted odds ratio 0.952; 95% CI, 0.850–1.066; P = 0.3981). A decreased EMT on day of the LH surge was significantly associated with greater female age (P = 0.0003) and a shortened follicular/proliferation phase (P < 0.0001).

LIMITATIONS, REASONS FOR CAUTION

The data used in this study were obtained from a single-centre cohort; therefore, multi-centre studies are required to ascertain the generalisability of these findings to other clinics with different protocols and/or patient demographics.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first report demonstrating a significant correlation between EMT on day of the LH surge and pregnancy outcomes after frozen blastocyst transfer in modified natural cycles. Our results suggest that EMT on day of the LH surge may be an effective predictor of the live birth rate.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by resources from the Kato Ladies Clinic. The authors have no conflicts of interest to declare.

Anti-Müllerian hormone is correlated with cumulative live birth in minimal ovarian stimulation with clomiphene citrate: a retrospective cohort study

BACKGROUND

Several studies have investigated the correlation between the serum anti-Müllerian hormone (AMH) level and in vitro fertilization (IVF) outcomes in controlled ovarian stimulation cycles; however, studies regarding the correlation of the serum AMH level with IVF outcomes in minimal ovarian stimulation cycles remain limited. In this study, we aimed to analyze the correlation of the serum AMH level with ovarian responsiveness, embryonic outcomes, and cumulative live birth rates in clomiphene citrate (CC)-based minimal ovarian stimulation cycles.

METHODS

Clinical records of 689 women whose entire ovarian stimulation regimen consisted solely of minimal stimulation cycle IVF using CC alone from November 2017 to October 2019 were retrospectively reviewed. The association between IVF outcomes and the serum AMH level before the initiation of the first fertility treatment was analyzed. Furthermore, the correlation of the serum AMH level with cumulative live birth rates after IVF treatment was assessed. The Cochran-Armitage test, Pearson's chi-squared test, Spearman rank correlation test, Student's t-test, one-way analysis of variance, logistic regression analysis, Kaplan-Meier method and Cox proportional hazards model were used to analyze the data.

RESULTS

The serum AMH level positively correlated with the number of retrieved oocytes, blastocyst formation rate, blastocyst cryopreservation rate, and live birth rate per oocyte retrieval in CC-based minimal ovarian stimulation cycles without any exogenous gonadotropin administration. Furthermore, the cumulative live birth rate and treatment period required for conceiving were strongly associated with the serum AMH level at the initiation of fertility treatment.

CONCLUSIONS

A low serum AMH level correlated with low ovarian responsiveness, impaired pre-implantation embryonic development, and decreased cumulative live birth rate in CC-based minimal ovarian stimulation cycles. Therefore, the cycle success rate would be predicted by measuring the serum AMH level in minimal ovarian stimulation with CC alone.

An elective single cleavage embryo transfer strategy to minimize twin live birth rate based on a prediction model from double cleavage embryos transfer patients

OBJECTIVE

To minimize twin birth rate by establishing an elective single cleavage embryo transfer strategy based on a twin live birth prediction model from fresh double cleavage embryos transfer (cleavage DET) patients.

METHODS

A total of 2478 patients underwent fresh cleavage DET in Nanjing Tower Hospital were enrolled to establish the twin live birth prediction model by logistic regression analysis and the cutoff value was calculated by ROC curve. Another 300 fresh cleavage DET patients and 550 cleavage single-embryo transfer (SET) patients were selected to testify the sensitivity, specificity and usefulness of this model.

RESULTS

The twin live birth probability (TLBP) = e^X /(e^X + 1), e is a natural logarithm, X = -1.763 - (0.319 × female age) + (0.329 × endometrial thickness) + (0.282 × the number of transferred top embryos) - (0.314 × previous transfer times), and the cutoff value of TLBP was 24.2%. The sensitivity of this model for predicting twin live birth was 75.6%, while the specificity was 52.5% in the external validation of 300 DET patients. Furthermore, the validation of 550 SET patients showed that the live birth rate of TLBP value positive patients was significantly higher than that in negative patients (54.3% vs. 35.5%, p < .001). When adopted an elective single cleavage embryo transfer strategy, the patients with a positive TLBP value choose SET, while still undergo DET who with a negative TLBP value, the live birth rate would maintain as 56.7%; however, the twin birth rate would significantly decline to 7.4%.

CONCLUSION

Female age, endometrial thickness, the number of transferred top embryos and previous embryo transfer times were critical variables for the twin live birth prediction model. An elective single cleavage embryo transfer strategy according to this model can maintain the relatively high live birth rate, meanwhile get the acceptable low twin birth rate.

Does the endometrial thickness on the day of the trigger affect the pregnancy outcomes after fresh cleaved embryo transfer in the clomiphene citrate-based minimal stimulation cycle?

PURPOSE

Thin endometrium is often observed after clomiphene citrate (CC) administration for follicular development and is one of the reasons for embryo transfer (ET) cancelation or implantation failure. We retrospectively analyzed whether the endometrial thickness (EMT) on the days of the maturation trigger and ET are predictive factors of pregnancy outcomes after fresh cleaved ET in a CC-based minimal stimulation cycle (CC-cycle).

METHODS

A total of 746 CC-cycles in vitro fertilization (IVF), followed by fresh cleaved ET, from November 2018 to March 2019 were analyzed. Associations between the pregnancy outcomes and EMT on the days of the trigger and ET were statistically evaluated.

RESULTS

Although the EMT on the day of ET was not significantly associated with the ongoing pregnancy rate (adjusted odds ratio [AOR], 1.043; P = .3251), a decreased EMT on the day of the trigger was significantly associated with a low ongoing pregnancy rate (AOR, 1.154; P = .0042). Furthermore, the clinical pregnancy rate was significantly lower when the EMT was <7 mm on the day of the trigger during the CC-cycle.

CONCLUSIONS

These results suggest that measurement of the EMT on the day of the trigger could be effective for predicting the pregnancy outcomes after fresh cleaved ET during the CC-cycle.

Effects of gonadotropin administration on clinical outcomes in clomiphene citrate-based minimal stimulation cycle IVF

PURPOSE

Exogenous gonadotropins (EGn) have been used occasionally in clomiphene citrate (CC)-based minimal stimulation cycles to compensate insufficient secretion of endogenous gonadotropin; however, the effectiveness of EGn supplementation remains unknown. In the present study, we assessed whether EGn improved pregnancy outcomes in CC-based minimal stimulation cycles.

METHODS

A total of 223 patients treated with CC and EGn (CC-EGn group) were matched one to one to patients treated with CC only (CC group) by propensity score matching. Embryonic and pregnancy outcomes were retrospectively compared between the groups.

RESULTS

The numbers of retrieved oocytes, fertilized oocytes, cleaved embryos, and cryopreserved blastocysts were increased in the CC-EGn group compared with the CC group. However, the cumulative live birthrate was comparable between the two groups. Although the increased number of retrieved oocytes was correlated significantly with improvement of the cumulative live birthrate in both groups, the correlation tended to be lower in the CC-EGn group than in the CC group (odds ratio, 1.193 vs 1.553).

CONCLUSIONS

In CC-based minimal stimulation cycles, the stimulation should be started with CC only, and EGn administration should be scheduled only if insufficient secretion of endogenous gonadotropin is observed in the late follicular phase.

Progestin-primed ovarian stimulation vs mild stimulation in women with advanced age above 40: a retrospective cohort study

BACKGROUND

Previous studies have demonstrated that progestin-primed ovarian stimulation (PPOS) protocol was a feasible and efficient method in in vitro fertilization (IVF) cycle. However, its application in women with advanced age has not been determined yet. The purpose of this study was to investigate its efficacy in women aged ≥40 years old.

METHODS

This retrospective cohort study included patients with ages of ≥40 years old at the time of ovarian stimulation. The embryonic and clinical outcome of mild stimulation and PPOS were compared. Primary outcome was top-quality embryo rate on day 3, and secondary outcome was clinical pregnancy rate.

RESULTS

Baseline characteristics of patients was similar in mild stimulation (122 cycles) and PPOS (47 cycles). No significant difference was found in the number of retrieved and mature oocytes and the fertilization and cleavage rates. Of interest, the rate of top-quality embryos was significantly higher in PPOS group (50.08% vs 33.29%, p = 0.015), with an increasing trend of viable embryo rate (73.55% vs 61.16%). A greater amount of gonadotropin was observed in PPOS group (2061.17 ± 1254.63 IU vs 1518.14 ± 547.25 IU, p < 0.05) in spite of comparable duration of stimulation. After FET cycle, no significant difference was found in the clinical pregnancy rates between mild stimulation (12.5%) and PPOS group (16.7%).

CONCLUSIONS

Higher percentage of top-quality embryos on Day 3 and comparable clinical pregnancy rate was obtained in PPOS protocol, which could be considered as a feasible ovarian stimulation protocol in women aged above 40 years old.

Blastomere movement post first cell division correlates with embryonic compaction and subsequent blastocyst formation

BACKGROUND

Blastomere movement (BMov) occurs after the first cell division in human embryos. This movement has been suggested as a prognostic parameter for pregnancy outcome prediction following cleavage-stage embryo transfer. However, the effect of BMov on preimplantation development and pregnancy outcome after blastocyst transfer remains unclear. Therefore, this study aimed to evaluate whether BMov after the first cell division is correlated with blastocyst formation rate and live birth rate after single vitrified-warmed blastocyst transfer (SVBT).

METHODS

Nine hundred and sixty-six embryos cultured in the EmbryoScope+® time-lapse system were retrospectively analyzed. The BMov type was categorized into three groups; namely, bouncing, wobbling, and twist-and-crumble. The BMov duration (dBMov) between the first (t2) and second cell division (t3) was monitored, and the ratio of dBMov to the duration of the 2-cell stage was calculated [dBMov/(t3-t2)]. Developmental rates to the 4-cell, 8-cell, morula, blastocyst, and expanded blastocyst stages were assessed, as well as blastocyst morphological grade. The correlations between dBMov and clinical pregnancy, ongoing pregnancy, and live birth rates were evaluated.

RESULTS

Increased dBMov/(t3-t2) was significantly correlated with decreased developmental rates to the 8-cell, morula, blastocyst, and expanded blastocyst stages, especially from the 4-cell stage to the morula stage. Analysis of different types of BMov revealed that embryos with bouncing movement exhibited significantly higher developmental rates to the 8-cell, morula, blastocyst, and expanded blastocyst stages compared with embryos with twist-and-crumble movement. The morphological quality of blastocyst-stage embryos with twist-and-crumble movement was significantly lower than that of embryos with bouncing and wobbling movements. The rates of clinical pregnancy, ongoing pregnancy, and live birth after SVBT were not correlated with BMov type or duration.

CONCLUSIONS

Embryonic compaction and subsequent blastocyst formation are adversely affected by twist-and-crumble movement and prolonged movement after the first cell division. Our results indicate that the preimplantation developmental competence of human embryos could be predicted by assessing BMov after the first cell division on day 1.

Prolonged blastomere movement induced by the delay of pronuclear fading and first cell division adversely affects pregnancy outcomes after fresh embryo transfer on Day 2: a time-lapse study

RESEARCH QUESTION

What is the incidence, origin and clinical significance of blastomere movement after the first cell division in the human embryo?

DESIGN

A total of 1096 embryos, cultured in the EmbryoScope+ ® time-lapse system and subjected to a single fresh cleaved embryo transfer, were retrospectively analysed. Type and duration of blastomere movement (dBMov) between the first (t2) and second cell division (t3) was monitored, and the ratio of dBMov during the 2-cell stage [dBMov/(t3-t2)] was calculated. Morphological evaluation of embryos was performed by referring to the size of the blastomere and fragmentation after first division in addition to Veeck's criteria on Day 2. The correlation between dBMov and ongoing pregnancy was evaluated and the association of dBMov with patient and embryonic characteristics was determined.

RESULTS

Both movement type and the value of dBMov/(t3-t2) were significantly associated with asymmetrical first division, fragment formation and morphological grade on Day 2. Multivariate logistic regression analysis revealed that a higher value of dBMov/(t3-t2) significantly correlated with a decreased ongoing pregnancy rate, even after adjustment for co-founders (odds ratio 0.399, P = 0.0419). The time intervals of pronuclear (PN) alignment and PN fading were significantly correlated with the dBMov/(t3-t2) value.

CONCLUSIONS

Embryos with extended blastomere movement after the first cell division, which is associated with the delay of PN fading and first cell division, have a lower competence to initiate an ongoing pregnancy after fresh embryo transfer on Day 2. Thus, blastomere movement could be a useful predictive parameter for selecting embryos at the early cleavage stage.