Effect of Embryo Developmental Stage, Morphological Grading, and Ploidy Status on Live Birth Rate in Frozen Cycles of Single Blastocyst Transfer

Antibiotics improve reproductive outcomes after frozen-thaw embryo transfer for chronic endometritis treatment, especially in those with repeated implantation failure

PURPOSE

To investigate the impact of antibiotic treatment for chronic endometritis (CE) on the pregnancy outcome of frozen-thawed embryo transfer (FET) cycles and the relevant clinical risk factors associated with CE.

METHODS

A retrospective cohort analysis was conducted on 1352 patients who underwent hysteroscopy and diagnostic curettage at Nanjing Maternal and Child Health Hospital from July 2020 to December 2021. All patients underwent CD138 immunohistochemical (IHC) testing to diagnose CE, and a subset of them underwent FET after hysteroscopy. Patient histories were collected, and reproductive prognosis was followed up.

RESULTS

Out of 1088 patients, 443 (40.7%) were diagnosed with CE. Univariate and multivariate binary logistic regression analyses revealed that parity ≥ 2, a history of ectopic pregnancy, moderate-to-severe dysmenorrhea, hydrosalpinx, endometrial polyps, a history of ≥ 2 uterine operations, and RIF were significantly associated with an elevated risk of CE (P < 0.05). Analysis of the effect of CE on pregnancy outcomes in FET cycles after antibiotic treatment indicated that treated CE patients exhibited a significantly lower miscarriage rate (8.7%) and early miscarriage rate (2.9%) than untreated non-CE patients (20.2%, 16.8%). Moreover, the singleton live birth rate (45.5%) was significantly higher in treated CE patients than in untreated non-CE patients (32.7%). Survival analysis revealed a statistically significant difference in the first clinical pregnancy time between treated CE and untreated non-CE patients after hysteroscopy (P = 0.0019). Stratified analysis based on the presence of recurrent implantation failure (RIF) demonstrated that in the RIF group, treated CE patients were more likely to achieve clinical pregnancy than untreated non-CE patients (P = 0.0021). Among hysteroscopy-positive patients, no significant difference was noted in pregnancy outcomes between the treatment and control groups (P > 0.05).

CONCLUSION

Infertile patients with a history of parity ≥ 2, hydrosalpinx, a history of ectopic pregnancy, moderate-to-severe dysmenorrhea, endometrial polyps, a history of ≥ 2 uterine operations, and RIF are at an increased risk of CE; these patients should be recommended to undergo hysteroscopy combined with CD138 examination before embryo transfer. Antibiotic treatment can improve the reproductive outcomes of FET in patients with CE, especially those with RIF.

Different endometrial preparation protocols on first frozen-thawed embryo transfer outcomes after hysteroscopic polypectomy: A retrospective cohort study

OBJECTIVE

To evaluate the optimal endometrial preparation protocol for frozen-thawed embryo transfer (FET) following hysteroscopic polypectomy.

METHODS

This was a retrospective clinical cohort study involving 464 patients who underwent their first FET after polyp resection between January 2021 and July 2023. The cohorts were categorized into three groups: the natural cycle (NC) group (n = 139), the ovarian induction (OI) group (n = 117), and the hormone replacement therapy (HRT) group (n = 208).

RESULTS

In the initial unadjusted analysis, both NC and OI cycles exhibited similar pregnancy rates but were associated with significantly higher implantation rate (56.5%, 57.1% vs 42.0%, P < 0.001), clinical pregnancy rate (73.4%, 74.4% vs 57.2%, P = 0.001), and ongoing pregnancy rate (OPR; 67.6%, 63.2% vs 51.0%, P = 0.005) compared to the HRT group. Additionally, the three groups demonstrated comparable abortion rate (7.8%, 14.9% vs 10.9%, P = 0.299). After adjusting for potential confounders in the multiple logistic regression model, the HRT protocol resulted in a 54% significantly lower OPR compared to the NC protocol (adjusted odds ratio [aOR] = 0.46, 95% confidence interval [CI]: 0.28-0.77; P = 0.003). Meanwhile, the OPR difference between the OI protocol and the NC protocol remained insignificant (OI vs NC: aOR = 0.62, 95% CI: 0.35-1.12; P = 0.112).

CONCLUSION

The ovulatory-FET scheme (NC and OI) following hysteroscopic polyp resection displayed promising clinical outcomes compared with HRT-FET scheme. The regimen without exogenous estrogen administration should be prioritized for endometrial preparation protocol after polypectomy.

Developing and validating a prediction model of live birth following single vitrified-warmed blastocyst transfer

RESEARCH QUESTION

Can the developed clinical prediction model offer an accurate estimate of the likelihood of live birth, involving blastocyst morphology and vitrification day after single vitrified-warmed blastocyst transfer (SVBT), and therefore assist clinicians and patients?

STUDY DESIGN

Retrospective cohort study conducted at a Spanish university-based reproductive medicine unit (2017-2021) including consecutive vitrified-warmed blastocysts from IVF cycles. A multivariable logistic regression incorporated key live birth predictors: vitrification day, embryo score, embryo ploidy status and clinically relevant variables, i.e. maternal age.

RESULTS

The training set involved 1653 SVBT cycles carried out between 2017 and 2020; 592 SVBT cycles from 2021 constituted the external validation dataset. The model revealed that female age and embryo characteristics, including overall quality and blastulation day, is linked to live birth rate in SVBT cycles. Stratification by vitrification day and quality (from day-5A to day-6 C blastocysts) applied to genetically tested and untested embryos. The model's area under the curve was 0.66 (95% CI 0.64 to 0.69) during development and 0.65 (95% CI 0.61 to 0.70) in validation, denoting moderate discrimination. Calibration plots showed strong agreement between predicted and observed probabilities.

CONCLUSION

By incorporating essential predictors such as vitrification day, embryo morphology grade, age and preimplantation genetic testing for aneuploidy usage, this predictive model offers valuable guidance to clinicians and patients, enabling accurate forecasts of live birth rates for any given vitrified blastocyst within SVBT cycles. Additionally, it serves as a potentially indispensable laboratory tool, aiding in selecting the most promising blastocysts for optimal outcomes.

Prioritized single vitrified blastocyst to be warmed between grades 3 or 4 blastocyst on day 5 transfer cycles

PURPOSE

Selecting the optimal blastocyst to implant during cryopreservation and warming is critial for in vitro fertilization success. Therefore, the aim of this study was to explore which blastocyst should be prioritized to be thawed when facing a single vitrified blastocyst on day 5 transfer.

METHODS

A retrospective study including 1,976 single vitrified-warmed blastocyst transfer cycles was conducted from January 2016 to December 2020.

RESULTS

We found that grade 4 vitrified blastocyst had a higher clinical pregnancy (60.64% vs. 49.48%, P < 0.001) and live birth rates (50.12% vs 39.59%, P < 0.001) than the grade 3 vitrified blastocyst. However, no statistical difference was found between groups in miscarriage rate, birth weight, or gestational age. Besides, the grade 4 vitrified-thawed blastocyst had significant potential to develop into grade 6 blastocyst after further culturing for 16 h (73.68% vs. 48.60%, P < 0.001). The grade 6 transferred blastocyst was markedly higher in both clinical pregnancy rate (61.88% vs. 51.53%, P < 0.001) and live birth rate (50.91% vs. 40.46%, P < 0.001) compared to grade 5 transferred blastocyst.

CONCLUSIONS

Grade 4 vitrified blastocyst is recommended when facing single vitrified blastocyst on day 5 transfer. More importantly, the "embryonic escape hypothesis" was firstly proposed to reveal the findings.

Opening the black box: why do euploid blastocysts fail to implant? A systematic review and meta-analysis

BACKGROUND

A normal chromosomal constitution defined through PGT-A assessing all chromosomes on trophectoderm (TE) biopsies represents the strongest predictor of embryo implantation. Yet, its positive predictive value is not higher than 50-60%. This gap of knowledge on the causes of euploid blastocysts' reproductive failure is known as 'the black box of implantation'.

OBJECTIVE AND RATIONALE

Several embryonic, maternal, paternal, clinical, and IVF laboratory features were scrutinized for their putative association with reproductive success or implantation failure of euploid blastocysts.

SEARCH METHODS

A systematic bibliographical search was conducted without temporal limits up to August 2021. The keywords were '(blastocyst OR day5 embryo OR day6 embryo OR day7 embryo) AND (euploid OR chromosomally normal OR preimplantation genetic testing) AND (implantation OR implantation failure OR miscarriage OR abortion OR live birth OR biochemical pregnancy OR recurrent implantation failure)'. Overall, 1608 items were identified and screened. We included all prospective or retrospective clinical studies and randomized-controlled-trials (RCTs) that assessed any feature associated with live-birth rates (LBR) and/or miscarriage rates (MR) among non-mosaic euploid blastocyst transfer after TE biopsy and PGT-A. In total, 41 reviews and 372 papers were selected, clustered according to a common focus, and thoroughly reviewed. The PRISMA guideline was followed, the PICO model was adopted, and ROBINS-I and ROB 2.0 scoring were used to assess putative bias. Bias across studies regarding the LBR was also assessed using visual inspection of funnel plots and the trim and fill method. Categorical data were combined with a pooled-OR. The random-effect model was used to conduct the meta-analysis. Between-study heterogeneity was addressed using I2. Whenever not suitable for the meta-analysis, the included studies were simply described for their results. The study protocol was registered at http://www.crd.york.ac.uk/PROSPERO/ (registration number CRD42021275329).

OUTCOMES

We included 372 original papers (335 retrospective studies, 30 prospective studies and 7 RCTs) and 41 reviews. However, most of the studies were retrospective, or characterized by small sample sizes, thus prone to bias, which reduces the quality of the evidence to low or very low. Reduced inner cell mass (7 studies, OR: 0.37, 95% CI: 0.27-0.52, I2 = 53%), or TE quality (9 studies, OR: 0.53, 95% CI: 0.43-0.67, I2 = 70%), overall blastocyst quality worse than Gardner's BB-grade (8 studies, OR: 0.40, 95% CI: 0.24-0.67, I2 = 83%), developmental delay (18 studies, OR: 0.56, 95% CI: 0.49-0.63, I2 = 47%), and (by qualitative analysis) some morphodynamic abnormalities pinpointed through time-lapse microscopy (abnormal cleavage patterns, spontaneous blastocyst collapse, longer time of morula formation I, time of blastulation (tB), and duration of blastulation) were all associated with poorer reproductive outcomes. Slightly lower LBR, even in the context of PGT-A, was reported among women ≥38 years (7 studies, OR: 0.87, 95% CI: 0.75-1.00, I2 = 31%), while obesity was associated with both lower LBR (2 studies, OR: 0.66, 95% CI: 0.55-0.79, I2 = 0%) and higher MR (2 studies, OR: 1.8, 95% CI: 1.08-2.99, I2 = 52%). The experience of previous repeated implantation failures (RIF) was also associated with lower LBR (3 studies, OR: 0.72, 95% CI: 0.55-0.93, I2 = 0%). By qualitative analysis, among hormonal assessments, only abnormal progesterone levels prior to transfer were associated with LBR and MR after PGT-A. Among the clinical protocols used, vitrified-warmed embryo transfer was more effective than fresh transfer (2 studies, OR: 1.56, 95% CI: 1.05-2.33, I2 = 23%) after PGT-A. Lastly, multiple vitrification-warming cycles (2 studies, OR: 0.41, 95% CI: 0.22-0.77, I2 = 50%) or (by qualitative analysis) a high number of cells biopsied may slightly reduce the LBR, while simultaneous zona-pellucida opening and TE biopsy allowed better results than the Day 3 hatching-based protocol (3 studies, OR: 1.41, 95% CI: 1.18-1.69, I2 = 0%).

WIDER IMPLICATIONS

Embryo selection aims at shortening the time-to-pregnancy, while minimizing the reproductive risks. Knowing which features are associated with the reproductive competence of euploid blastocysts is therefore critical to define, implement, and validate safer and more efficient clinical workflows. Future research should be directed towards: (i) systematic investigations of the mechanisms involved in reproductive aging beyond de novo chromosomal abnormalities, and how lifestyle and nutrition may accelerate or exacerbate their consequences; (ii) improved evaluation of the uterine and blastocyst-endometrial dialogue, both of which represent black boxes themselves; (iii) standardization/automation of embryo assessment and IVF protocols; (iv) additional invasive or preferably non-invasive tools for embryo selection. Only by filling these gaps we may finally crack the riddle behind 'the black box of implantation'.

The correlation between morphological parameters and the incidence of de novo chromosomal abnormalities in 3238 biopsied blastocysts

PURPOSE

The aim of this study was to determine the relationship between morphological parameters and the incidence of de novo chromosomal abnormalities.

METHODS

This was a retrospective cohort study of 652 patients who underwent 921 cycles with 3238 blastocysts biopsied. The embryo grades were evaluated according to Gardner and Schoolcraft's system. The incidence of euploidy, whole chromosomal aneuploidy (W-aneuploidy), segmental chromosomal aneuploidy (S-aneuploidy), and mosaicism in trophectoderm (TE) cell biopsies was analyzed.

RESULTS

The euploidy decreased significantly with maternal age and was positively correlated biopsy day and morphological parameters. The W-aneuploidy increased significantly with maternal age and was negatively correlated biopsy day and morphological parameters. Parental age, TE biopsy day, and morphological parameters were not associated with S-aneuploidy and mosaicism, except that TE grade C blastocysts had significantly higher mosaicism than TE grade A blastocysts. Subanalysis in different female age groups showed that euploidy and W-aneuploidy had a significant correlation with TE biopsy day among women aged ≤ 30 y and 31-35 y, with expansion degree among women aged ≥ 36 y, with ICM grade among women aged ≥ 31 y, and with TE grade among all female age ranges.

CONCLUSION

Female age, embryo developmental speed and blastocyst morphological parameters are associated with euploidy and whole chromosomal aneuploidy. The predictive value of these factors varies across female age groups. Parental age, embryo developmental speed, expansion degree, and ICM grade are not associated with the incidence of segmental aneuploidy or mosaicism, but TE grade seemingly has a weak correlation with segmental aneuploidy and mosaicism in embryos.

Microbiological and Cytokine Profiling of Menstrual Blood for the Assessment of Endometrial Receptivity: A Pilot Study

Endometrial receptivity (ER) is a key factor required for the successful implantation of the embryo. However, the evaluation of ER is challenging, as a nondisruptive sampling of endometrial biomaterial by conventional methods is only possible outside of the embryo transfer (ET) cycle. We propose a novel approach for the assessment of ER-microbiological and cytokine profiling of menstrual blood aspirated directly from the uterine cavity at the beginning of the cryo-ET cycle. The aim of the pilot study was to evaluate its prognostic potential regarding the outcome of the in vitro fertilization procedure. Samples collected from a cohort of 42 patients undergoing cryo-ET were analyzed by a multiplex immunoassay (48 various cytokines, chemokines, and growth factors) and a real-time PCR assay (28 relevant microbial taxa and 3 members of the Herpesviridae family). Significant differences between groups of patients who achieved and did not achieve pregnancy were observed for G-CSF, GRO-α, IL-6, IL-9, MCP-1, M-CSF, SDF-1α, TNF-β, TRAIL, SCF, IP-10, and MIG (p < 0.05), whereas microbial profiles were not associated with the outcome of cryo-ET. It appeared that levels of IP-10 and SCGF-β were significantly lower (p < 0.05), in patients with endometriosis. Menstrual blood may provide great opportunities to noninvasively investigate various parameters of the endometrium.

Trophectoderm biopsy is associated with adverse obstetric outcomes rather than neonatal outcomes

BACKGROUND

With the wide application of preimplantation genetic testing (PGT) with trophectoderm (TE) biopsy, the safety of PGT has always been a concern. Since TE subsequently forms the placenta, it is speculated that the removal of these cells was associated with adverse obstetrical or neonatal outcomes after single frozen-thawed blastocyst transfer (FBT). Previous studies report contradictory findings with respect to TE biopsy and obstetric and neonatal outcomes.

METHODS

We conducted a retrospective cohort study including 720 patients with singleton pregnancies from single FBT cycles who delivered at the same university-affiliated hospital between January 2019 and March 2022. The cohorts were divided into two groups: the PGT group (blastocysts with TE biopsy, n = 223) and the control group (blastocysts without biopsy, n = 497). The PGT group was matched with the control group by propensity score matching (PSM) analysis at a ratio of 1:2. The enrolled sample sizes in the two groups were 215 and 385, respectively.

RESULTS

Patient demographic characteristics were comparable between the groups after PSM except for the proportion of recurrent pregnancy loss, which was significantly higher in the PGT cohort (31.2 vs. 4.2%, P < 0.001). Patients in the PGT group had significantly higher rates of gestational hypertension (6.0 vs. 2.6%, adjusted odds ratio (aOR) 2.91, 95% confidence interval (CI) 1.18-7.18, P = 0.020) and abnormal umbilical cord (13.0 vs. 7.8%, aOR 1.94, 95% CI 1.08-3.48, P = 0.026). However, the occurrence of premature rupture of membranes (PROM) (12.1 vs. 19.7%, aOR 0.59, 95% CI 0.35-0.99, P = 0.047) was significantly lower in biopsied blastocysts than in unbiopsied embryos. There were no significant differences in regard to other obstetric and neonatal outcomes between the two groups.

CONCLUSIONS

Trophectoderm biopsy is a safe approach, as the neonatal outcomes from biopsied and unbiopsied embryos were comparable. Furthermore, PGT is associated with higher risks of gestational hypertension and abnormal umbilical cord but may have a protective effect on PROM.

Influence of post-thaw culture duration on pregnancy outcomes in frozen blastocyst transfer cycles

In this study, we aimed to evaluate whether post-thaw culture duration affected the clinical outcomes of frozen blastocyst transfer. This retrospective cohort study included 3,901 frozen-thawed blastocyst transfer cycles. The cohorts were divided into two groups based on the developmental stage (day 5 [D5] and day 6 [D6]) and culture duration after thawing (short culture, 2-6 h; long culture, 18-20 h). Women in the short culture group following D6 blastocyst transfer were further divided into three subgroups depending on the post-thaw culture period (2, 4, and 6 h). The main outcomes, namely live birth rate (LBR), implantation rate (IR), clinical pregnancy rate (CPR), and abortion rate (AR), showed no statistical differences within the groups following D5 blastocyst transfer. Patients in the long culture group had significantly lower IR (35.5 vs. 45.8%, p < 0.001), CPR (45.3 vs. 56.6%, p = 0.001), and LBR (35.5 vs. 48.5%, p < 0.001) but a significantly higher AR (21.6 vs. 14.3%, p = 0.049) following D6 blastocyst transfer than those in the short culture group. However, the data failed to present the superiority of any short culture duration over another on the live birth outcome for embryos vitrified on D6 (adjusted odds ratio [aOR]: 0.96, 95% confidence interval [95% CI]: 0.53-1.73, p = 0.881, for the 4-h vs. 2-h subgroup; aOR: 1.01, 95% CI: 0.68-1.49, p = 0.974, for the 6-h vs. 2-h subgroup). Both post-thaw protocols can be applied to patients with D5 blastocysts. To optimize the pregnancy outcomes following D6 blastocyst transfer, a short culture period is recommended. Any of the three short culture durations (2, 4, and 6 h) can be applied, depending on the workflow of the laboratory.

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.

The role of timing in frozen embryo transfer

The process of implantation is characterized by a complex cross-talk between the endometrium and the blastocyst, with the endometrium only being receptive to implantation during a transient window of implantation of approximately 2-3 days during the midsecretory phase. The timing of embryo transfer, including frozen embryo transfer, is therefore critical to the success of implantation. In this article, we discuss various elements that may guide the timing of frozen embryo transfer, including the role of endometrial characteristics such as thickness, days postovulation or length of progesterone administration, stage of the embryo, and the application of endometrial receptivity tests to guide personalized embryo transfer.

Does the cell number of 0PN embryos on day 3 affect pregnancy and neonatal outcomes following single blastocyst transfer?

Background

0PN zygotes have a low cleavage rate, and the clinical outcomes of cleavage-stage embryo transfers are unsatisfactory. Blastocyst culturing is used to screen 0PN embryos, but whether the cell number of 0PN embryos on day 3 affects the clinical outcomes following single blastocyst transfer is unknown and would be helpful in evaluating the clinical value of these embryos.

Methods

This retrospective study compared 46,804 0PN zygotes, 242 0PN frozen-thawed single blastocyst transfers, and 92 corresponding 0PN singletons with 232,441 2PN zygotes, 3563 2PN frozen-thawed single blastocyst transfers, and 1250 2PN singletons from January 2015 to October 2019 at a tertiary-care academic medical centre. The 0PN and 2PN embryos were divided into two groups: the group with < 6 cells on day 3 and that with ≥ 6 cells. Embryo development, subsequent pregnancy and neonatal outcomes were compared between the two groups.

Results

The cleavage and available blastocyst rates of the 0PN zygotes were much lower than those of the 2PN zygotes (25.9% vs. 97.4%, P < 0.001; 13.9% vs. 23.4%, P < 0.001). In the < 6 cells group, the available blastocyst rate of the cleaved 0PN embryos was significantly lower than that of the 2PN embryos (2.5% vs. 12.7%, P < 0.001). However, in the ≥ 6 cells group, the available blastocyst rate of the 0PN cleaved embryos significantly improved, although it was slightly lower than that of the 2PN embryos (33.9% vs. 35.7%, P = 0.014). Importantly, compared to those of the 2PN single blastocyst transfers, the clinical pregnancy rate, live birth rate, Z-score and malformation rate of the 0PN single blastocyst transfers were not significantly different in either the < 6 cells group (30.4% vs. 39.8%, P = 0.362; 30.4% vs. 31.3%, P = 0.932; 0.89 ± 0.90 vs. 0.42 ± 1.02, P = 0.161; 0% vs. 2.6%, P = 1.000) or the ≥ 6 cells group (50.7% vs. 46.6%, P = 0.246; 39.7% vs. 38.3%, P = 0.677; 0.50 ± 1.23 vs. 0.47 ± 1.11, P = 0.861; 2.4% vs. 1.8%, P = 1.000).

Conclusions

The cell number on day 3 of 0PN embryos affected the subsequent formation of blastocysts but did not influence the subsequent pregnancy and neonatal outcomes of 0PN single blastocyst transfers, which may be beneficial to clinicians counselling patients on the clinical value of 0PN embryos.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04492-7.

Day 5 vs day 6 single euploid blastocyst frozen embryo transfers: which variables do have an impact on the clinical pregnancy rates?

OBJECTIVE

To determine which variables affect most the clinical pregnancy rate with positive fetal heartbeat (CPR FHB+) when frozen embryo transfer (FET) cycles are performed with day 5 (D5) or day 6 (D6) euploid blastocysts. Design and method A single center retrospective study was performed from March 2017 till February 2021 including all single FET cycles with euploid D5 or D6 blastocysts and transferred in natural cycles (NC) or hormone replacement therapy (HRT) cycles. Trophectoderm (TE) and inner cell mass (ICM) qualities were recorded before biopsy.

RESULTS

A total of 1102 FET cycles were included, 678 with D5 and 424 with D6 blastocysts. Pregnancy rate (PR), clinical PR (CPR), and CPR FHB+ were significantly higher with D5 blastocysts (PR: 70.7% vs 62.0%, OR = 0.68 [0.53-0.89], p = 0.004; CPR: 63.7% vs 54.2%, OR = 0.68 [0.52-0.96], p = 0.002 and CPR FHB+: 57.8% vs 49.8%, OR = 0.72 [0.53-0.96], p = 0.011). However, miscarriage rate (12.5% vs 11.4%, OR = 0.78 [0.48-1.26], p = 0.311) did not differ. From a multivariate logistic regression model, endometrial thickness (OR = 1.11 [1.01-1.22], p = 0.028), patient's age (OR = 1.03 [1.00-1.05], p = 0.021), BMI (OR = 0.97 [0.94-0.99], p = 0.023), and ICM grade C (OR = 0.23 [0.13-0.43], p < 0.001) were significant in predicting CPR FHB+.

CONCLUSION

Although clinical outcomes are higher with D5 blastocysts, CPR FHB+ is more affected by endometrial thickness, patient age, BMI, and ICM grade C rather than biopsy day or endometrial preparation protocol.

Functional Ovarian Cysts in Artificial Frozen-Thawed Embryo Transfer Cycles With Depot Gonadotropin-Releasing Hormone Agonist

OBJECTIVES

To investigate the incidence of functional ovarian cysts, its influence on clinical rates, and proper management after depot gonadotropin-releasing hormone (GnRH) agonist pretreatment in artificial frozen-thawed embryo transfer cycles (AC-FET).

METHODS

This retrospective cohort study involved 3375 AC-FET cycles with follicular-phase depot GnRH agonist administration between January 2017 and December 2020. Subjects were divided into a study group (cycles with cyst formation) and a control group (cycles without cyst formation). The study group was matched by propensity scoring matching with the control group at a ratio of 1:2. For patients with ovarian cyst formation, two major managements were used: a conservative approach (i.e., expectant treatment) and a drug approach (i.e., continued agonist administration). The primary outcome was live birth rate (LBR).

RESULTS

The incidence of functional ovarian cysts following pituitary downregulation is 10.1% (341/3375). The study group exhibited a LBR similar to the control group (54.5% vs. 50.1%, adjusted odds ratio [aOR] 1.17, 95% confidence interval [CI] 0.88-1.56, P = 0.274). Patients with a lower body mass index and anti-Müllerian hormone, and a higher basal estradiol level were more susceptible to developing functional ovarian cysts. The LBR decreased after the drug approach compared with the conservative approach, but not significantly (aOR 0.63, 95% CI 0.35-1.14, P = 0.125). Following the conservative approach, cycles arrived at live births had a significantly shorter duration from the detection of functional cysts to the start of endometrium preparation (15.7 ± 5.1 days vs. 17.4 ± 5.3 days, P = 0.009) and a significantly higher proportion of ovarian cysts on the initial day of exogenous hormone supplementation (51.4% vs. 30.3%, P = 0.001). After controlling for all confounders, the differences remained statistically significant.

CONCLUSIONS

It is unnecessary to cancel cycles that experience functional ovarian cyst formation. Conservative management and further agonist suppression protocol had similar pregnancy rates. However, a conservative approach was recommended due to its lower cost and fewer side effects. Our findings support a shorter waiting period when choosing the conservative protocol.

Euploid day 7 blastocysts of infertility patients with only slow embryo development have reduced implantation potential

RESEARCH QUESTION

What is the reproductive potential of embryos that achieve blastulation on day 7 followed by preimplantation genetic testing for aneuploidies (PGT-A) for infertility patients with slow embryo development?

DESIGN

This was a retrospective cohort study in a private IVF clinic of consecutive female infertility patients (n = 2966) aged 24-48 (36.3 ± 3.8) years who underwent frozen embryo transfer (FET) of a single euploid blastocyst.

RESULTS

The women underwent single euploid FET of an embryo that achieved blastulation on day 5 (n = 1880), day 6 (n = 986) or day 7 (n = 100). Day 7 embryos resulted in lower implantation and live birth rates compared with both day 5 and day 6 embryos (P < 0.001). The day 5, day 6 and day 7 groups had 68.5%, 55.2% and 36.0% live birth rates, respectively. The day 7 group was older than the day 5 group (P < 0.001); comparing age-matched cohorts, the day 7 group still had lower implantation and live birth rates (P < 0.0001 and P < 0.001, respectively). Embryo grade was unrelated to live birth rates. Day 7 embryos of expansion grade 5 or 6 or trophectoderm grade A were more likely to be euploid compared with expansion grade 3 or trophectoderm grade B.

CONCLUSIONS

Euploid day 7 embryos represented reduced implantation potential, even when controlling for maternal age. Of all day 7 embryos that underwent PGT-A, euploidy was associated with expansion grade 5 or 6 and trophectoderm grade A. These results can help providers manage patient expectations in cases where infertile women have slow embryo development.