Pregnancy and neonatal outcomes of morphologically grade CC blastocysts: are they of clinical value?

Pregnancy and neonatal outcomes of blastocysts without blastocoele re-expansion in FET patients: are they of clinical value?

OBJECTIVE

To study if the transfer of warmed blastocysts without blastocoele re-expansion is effective and safe.

METHODS

Three thousand one hundred ninety-six frozen-thawed single blastocyst transfer cycles were conducted. The embryos were categorized into two groups based on the occurrence of blastocoele re-expansion following a post-warming culture period of 3-4 h, including non-re-expanded blastocyst transfer group (n = 431) and re-expanded blastocyst transfer group (n = 2765). Propensity score matching was utilized to mitigate potential confounding factors across groups. The pregnancy and neonatal outcomes were analyzed and compared between the two groups before and after the implementation of propensity score matching.

RESULTS

The rates of biochemical pregnancy, clinical pregnancy, intrauterine implantation, and live birth were significantly lower in the group that received a single frozen-thawed blastocyst without blastocoele re-expansion transfer, in comparison to the re-expanded blastocyst transfer group (before matching: 29.5% versus 60.7%, 21.6% versus 51.9%, 22.3% versus 52.0%, and 16.9% versus 41.6%, respectively, all P < 0.01). However, upon evaluating the pregnancy outcomes, no statistically significant differences were observed in the rates of ectopic pregnancy, miscarriage, multiple gestation, multiple births, and gestational age (P > 0.05) between the two groups. Furthermore, no significant differences were observed in neonatal outcomes, including live born infants, birth weight, delivery, and birth defects. Additionally, similar findings were also noted in the two matched cohorts after propensity score matching.

CONCLUSION

Warmed blastocysts that do not exhibit blastocoele re-expansion following a 3-4-h culture may be considered for transfer rather than being discarded in frozen-thawed embryo transfer (FET) cycles, resulting in acceptable clinical outcomes.

Pregnancy and neonatal outcomes of borderline blastocysts: a novel evaluation model based on inner cell mass and trophectoderm parameters

PURPOSE

To investigate the applicability and safety of the blastocyst grading system for borderline blastocysts assessed by measurement of the inner cell mass (ICM) and trophectoderm (TE) parameters.

METHODS

A total of 361 borderline blastocysts were classified as B-B-, B-C, and CB/CB-blastocysts based on the parameters of the ICM and TE in frozen-thawed embryo transfer cycles, and these embryos were divided into groups A, B, and C. The primary outcome measures were clinical pregnancy rate (CPR), live birth rate (LBR), gestational age (GA) at birth, birth weight, and malformation rate. Four embryologists independently evaluated 90 embryos, with inter- and intra-observer agreement analyzed using Fleiss' kappa coefficient.

RESULTS

The CPR (9.1%) and LBR (5.5%) in group C were lower than those in groups A (34.9% and 25.6%, respectively) and B (25.3% and 19.0%, respectively). There were no differences in GA at birth, birth weight, or malformation rate among groups A, B, and C. Binary regression analysis revealed that embryos with an ICM grade of C (OR 0.158; 95% CI 0.073-0.439; P < 0.001) had a lower likelihood of LBR than those with an ICM grade of B-. The inter- and intra-observer agreement between embryologists in terms of embryo morphological grading and clinical decision-making ranged from good (K > 0.61) to very good (K > 0.81).

CONCLUSION

The modified grading system to assess borderline blastocysts is safe and effective and improves the consistency of embryo assessment.

[Increasing the cumulative live birth rate: Low-grade blastocysts, potential overlook]

It is now widely recognized that, following prolonged culture, the transfer of a high-quality morphologically graded blastocyst is the preferred strategy in embryo transfer. Low-grade blastocysts are often considered to have a low implantation potential, and their use remains highly limited. We conducted a general review of the literature, including publications from August 2017 to October 2023, to assess the current state of knowledge regarding these embryos, which are generally excluded in routine practice. Our primary outcome measure was the "live birth rate" following the frozen transfer of a low-grade morphologically classified blastocyst according to the Gardner classification. The "miscarriage rates" were also evaluated. The bibliographic research led to the selection of 9 articles. Low-grade blastocysts can result in live births, with rates ranging from 5.97 to 40%, and in the birth of healthy children, which remains the primary goal of assisted reproductive technology. It would therefore be relevant to reconsider the routine use of these embryos.

Pregnancy and neonatal outcomes of ICSI using pentoxifylline to identify viable spermatozoa in patients with frozen-thawed testicular spermatozoa

Introduction

Although the effectiveness of pentoxifylline (PF) as a selective inhibitor of phosphodiesterase to enhance sperm motility through increasing cyclic nucleotide in cases of absolute asthenozoospermia has been demonstrated for ICSI, data related to babies born from the PF-ICSI are still severely lacking. Concerns have been raised regarding the potential embryotoxicity of PF due to the controversial results obtained from the analysis of this compound on animal embryo development. This study aimed to determine whether the application of PF to trigger frozen-thawed TESA (testicular sperm aspiration) spermatozoa increases the risk of adverse obstetric and neonatal outcomes compared with non-PF frozen-thawed TESA ICSI and conventional ICSI using fresh ejaculation.

Materials and methods

A total of 5438 patients were analyzed in this study, including 240 patients underwent PF-TESA ICSI (ICSI using PF triggered frozen-thawed testicular spermatozoa), 101 patients underwent non-PF TESA ICSI (ICSI using frozen-thawed testicular spermatozoa) and 5097 patients underwent conventional ICSI using fresh ejaculation. Propensity score matching was executed to control the various characteristics of patients.

Results

No significant differences in pregnancy outcomes were observed among the three groups (PF-TESA ICSI, non-PF TESA ICSI and conventional ICSI), including biochemical pregnancy, clinical pregnancy, implantation, miscarriage, ectopic pregnancy, multiple pregnancy, and live birth, following propensity score matching. Additionally, neonatal outcomes were found to be similar among the three groups, with no statistical differences observed in the birth defect, birth weight, gestational age, preterm birth, and early-neonatal death.

Discussion and conclusion

PF-ICSI may be an alternative treatment in patients using frozen-thawed testicular spermatozoa, resulting in comparable pregnancy and neonatal outcomes.

Effect of development speed and quality of blastocyst on singleton birthweight in single frozen-thawed blastocyst transfer cycles

Background

Assisted reproductive technology (ART) has revolutionized infertility treatment, leading to a surge in ART-conceived children. Despite its success, ART-born offspring face higher risks of preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA). The mechanisms behind these outcomes remain unclear, partly attributed to multiple embryo transfers. Recent advancements advocate single blastocyst transfers for improved outcomes. However, the influence of blastocyst quality and development speed on neonatal outcomes is underexplored.

Objective

This study investigated whether blastocyst development speed and quality affect singleton birthweight when the blastocyst is selected for single frozen-thawed blastocyst transfer (FBT).

Methods

Data from patients who performed an FBT cycle at our center from July 2011 to June 2021 were collected and analyzed. Based on the inclusion and exclusion criteria, 420 single FBT cycles were assessed. The women were divided into four groups, Group A (day 5, good-quality blastocysts), Group B (day 5, non-good-quality blastocysts), Group C (day 6, good-quality blastocysts), and Group D (day 6, non-good-quality blastocysts) according to the developmental speed and quality of the transferred blastocyst.

Results

The birthweight was relatively the highest in Group A, which developed rapidly and transferred good quality blastocysts. However, no significant difference existed among the groups (P>0.05). The prevalence of premature birth (PTB), low birth weight (LBW), very low birth weight (VLBW), or high birth weight (HBW) was similar among the four groups (P > 0.05). No correlation existed between birth weight and blastocyst development speed or quality after adjusting for possible confounders (P > 0.05 respectively). However, the difference in the proportion of males born among the four groups was significant, especially in Group D, which was significantly lower than that in Group A (adjusted odds ratio = 0.461, 95% confidence interval: 0.230-0.921, P < 0.05).

Conclusions

This retrospective cohort study suggests that the combined effect of blastocyst development speed and quality on neonatal birthweight is insignificant. The transfer of slow-growing, non-good-quality blastocysts increases the chance of a female baby being born.

Blastocyst quality and reproductive and perinatal outcomes: a multinational multicentre observational study

STUDY QUESTION

Does the transfer of single low-grade blastocysts result in acceptable reproductive and perinatal outcomes compared to the transfer of single good-grade blastocysts?

SUMMARY ANSWER

The transfer of single low-grade blastocysts resulted in a reduced live birth rate of around 30% (14% for very low-grade blastocysts) compared to 44% for single good-grade blastocysts, but does not lead to more adverse perinatal outcomes.

WHAT IS KNOWN ALREADY

It is known that low-grade blastocysts can result in live births. However, the current studies are limited by relatively small sample sizes and single-centre designs. Furthermore, evidence on perinatal outcomes after transferring low-grade blastocysts is limited.

STUDY DESIGN, SIZE, DURATION

We conducted a multi-centre, multi-national retrospective cohort study of 10 018 women undergoing 10 964 single blastocyst transfer cycles between 2009 and 2020 from 14 clinics across Australia, China, and New Zealand.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Blastocysts were graded individually based on assessment of the morphology and development of the inner cell mass (ICM) and trophectoderm (TE), and were grouped into three quality categories: good- (AB, AB, or BA), moderate- (BB), and low-grade (grade C for ICM or TE) blastocysts. CC blastocysts were individually grouped as very low-grade blastocysts. Logistic regression with generalized estimating equation was used to analyse the association between blastocyst quality and live birth as well as other reproductive outcomes. Binomial, multinomial logistic, or linear regression was used to investigate the association between blastocyst quality and perinatal outcomes. Odds ratio (OR), adjusted OR (aOR), adjusted regression coefficient, and their 95% CIs are presented. Statistical significance was set at P < 0.05.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 4386 good-grade blastocysts, 3735 moderate-grade blastocysts, and 2843 low-grade blastocysts were included in the analysis, for which the live birth rates were 44.4%, 38.6%, and 30.2%, respectively. Compared to good-grade blastocysts, the live birth rate of low-grade blastocysts was significantly lower (aOR of 0.48 (0.41-0.55)). Very low-grade blastocysts were associated with an even lower live birth rate (aOR 0.30 (0.18-0.52)) and their absolute live birth rate was 13.7%. There were 4132 singleton live births included in the analysis of perinatal outcomes. Compared with good-grade blastocysts, low-grade blastocysts had comparable preterm birth rates (<37 weeks, aOR 1.00 (0.65-1.54)), birthweight Z-scores (adjusted regression coefficient 0.02 (0.09-0.14)), and rates of very low birth weight (<1500 g, aOR 0.84 (0.22-3.25)), low birth weight (1500-2500 g, aOR 0.96 (0.56-1.65)), high birth weight (>4500 g, aOR 0.93 (0.37-2.32)), small for gestational age (aOR 1.63 (0.91-2.93)), and large for gestational age (aOR 1.28 (0.97-1.70)).

LIMITATIONS, REASONS FOR CAUTION

Due to the nature of the retrospective design, residual confounding could not be excluded. In addition, the number of events for some perinatal outcomes was small. Between-operator and between-laboratory variations in blastocyst assessment were difficult to control.

WIDER IMPLICATIONS OF THE FINDINGS

Patients undergoing IVF should be informed that low-grade blastocysts result in a lower live birth rate, however they do not increase the risk of adverse perinatal outcomes. Further research should focus on the criteria for embryos that should not be transferred and on the follow-up of long-term outcomes of offspring.

STUDY FUNDING/COMPETING INTEREST(S)

H.Z. is supported by a Monash Research Scholarship. B.W.J.M. is supported by a NHMRC Investigator grant (GNT1176437). R.W. is supported by an NHMRC Emerging Leadership Investigator grant (2009767). B.W.J.M. reports consultancy, travel support, and research funding from Merck. The other authors do not have competing interests to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Evaluation of Clinical Outcomes after Poor-Quality Embryo Transfer and Prognostic Parameters

We aimed to investigate the clinical results following poor-quality embryo transfer and the parameters to foresee the prognosis. In this study, 2123 cycles that had day 3 and day 5 single-fresh embryo with poor-quality embryo transfers and good-quality embryo transfers were compared. The cycles according to transfer day were evaluated by conducting a subgroup analysis. The correlation between all the obtained demographic characteristics, controlled ovarian stimulation parameters, and cycle results were analysed. Clinical pregnancy was established in 53 patients that underwent transfer in the poor-quality embryo group (14.9%). Of these patients, 36 had live birth (live birth rate per clinical pregnancy 67.9%). In cleavage-stage embryos, live birth rates per clinical pregnancy were higher in poor-quality blastocyst transfer. When analysing the factors affecting live births in the poor-quality embryo group, as the total gonadotropin dose increases, the probability of live birth decreases, as in the probability of hCG positivity. In conclusion, although the probability of pregnancy is low, when clinical pregnancy is established, there is a high chance of having a live birth after poor-quality embryo transfers. This could be regarded as an acceptable option in cycles when only poor-quality embryos are available.

Association between embryo morphological quality and birth weight for singletons conceived via autologous fresh embryo transfer: an analysis using Society for Assisted Reproductive Technology Clinical Outcomes Reporting System

OBJECTIVE

To determine if morphologically suboptimal embryo quality is associated with adverse perinatal outcomes.

DESIGN

A retrospective cohort.

SETTING

SART CORS database.

PATIENT(S)

Singletons conceived from autologous in vitro fertilization fresh cycles.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Birth weight (gram), birth weight z-score, low birth weight (LBW), small for gestational age (SGA), and large for gestational age (LGA).

RESULT(S)

Among 5,869 in vitro fertilization fresh cycles, 71.1% transferred morphologically good embryos, and 27.0% and 1.9% transferred fair and poor embryo(s), respectively. Compared with singletons conceived from good embryos, singletons from poor embryos had a higher birth weight (3,415.8 ± 562.0 vs. 3,202.7 ± 639.9). Proportions of LBW, SGA, and LGA were comparable across embryo quality groups. Multivariate regression analysis comparing perinatal outcomes from fair vs. good embryos showed no association for birth weight (0.69-gram difference; 95% CI, -24.30-25.68), birth weight z-score (Coefficient, 0.00; 95% CI, -0.07-0.08), LBW (adjusted odds ratio [aOR], 0.84; 95% CI, 0.63-1.11), SGA (aOR, 0.93; 95% CI, 0.78-1.11), and LGA (aOR, 1.07; 95% CI, 0.86-1.33). Stratified analysis, considering cleaved and blastocyst embryo transfers separately, confirmed these findings. Sensitivity analysis revealed increased odds of LGA (aOR, 1.53; 95% CI, 1.04-2.24) with fair-quality embryos only among single embryo transfer cycles.

CONCLUSION(S)

Once a singleton live birth from fresh embryo transfer is achieved, fair morphological embryo quality is not associated with a reduction in birth weight or increased risks of LBW, SGA, and LGA.

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.

Blastocyst quality and perinatal outcomes in women undergoing single blastocyst transfer in frozen cycles

STUDY QUESTION

Is the morphological grading system for blastocysts associated with perinatal outcomes in women undergoing frozen-thawed single blastocyst transfer (SBT)?

SUMMARY ANSWER

Preferential transfer of a blastocyst based on their inner cell mass (ICM) and trophectoderm (TE) grading appears to be supported by observed differences in perinatal outcomes.

WHAT IS KNOWN ALREADY

The transfer of a morphologically good quality blastocyst is associated with a higher chance of implantation and pregnancy as compared to transfer of a poor quality blastocyst. However, to date, the association of the morphological parameters of the blastocyst with perinatal outcomes after blastocyst transfer remains unknown.

STUDY DESIGN SIZE DURATION

This retrospective cohort study started with 27 336 frozen-thawed SBT cycles from January 2013 to December 2019.

PARTICIPANTS/MATERIALS SETTING METHODS

There were 7469 women with singleton deliveries in Peking University Third Hospital eligible for analysis. Multivariate logistic regression was used to test the risk of factors with the expression of crude odds ratios (ORs) and adjusted OR with 95% CIs.

MAIN RESULTS AND THE ROLE OF CHANCE

Transfer of a blastocyst with a low overall grading was associated with a higher chance of female baby (48% vs 42%, adjusted OR = 1.26 (1.13, 1.39)) and a higher rate of caesarian section (C-section; 71% vs 68%, adjusted OR = 1.15 (1.02, 1.29)). Compared with Grade A ICM blastocyst transfer, Grade B ICM and Grade C ICM blastocyst transfers were associated with a lower chance of a female baby (adjusted OR = 0.83 (0.73, 0.95), 0.63 (0.50, 0.79), respectively) and a higher risk of large for gestational age (LGA; adjusted OR = 1.23 (1.05, 1.45), 1.47 (1.12, 1.92), respectively); Grade C ICM blastocyst transfer was also associated with an increased risk of macrosomia (adjusted OR = 1.66 (1.20, 2.30)). Compared with Grade A TE blastocyst transfer, there was an increased risk of small for gestational age with Grade C TE blastocyst transfer (adjusted OR = 1.74 (1.05, 2.88)). Both Grade B TE and Grade C TE blastocyst transfer had a higher chance of female baby (adjusted OR = 1.30 (1.11, 1.53), 1.88 (1.57, 2.26), respectively) and a lower risk of gestational diabetes mellitus (adjusted OR = 0.74 (0.59, 0.94), 0.67 (0.50, 0.88), respectively) than Grade A TE blastocyst transfer.

LIMITATIONS REASONS FOR CAUTION

The main limitations of this study were its retrospective nature and the relative subjectivity of blastocyst scoring. The follow-up was conducted through a phone call and some patients may not have reported their obstetrical and neonatal outcomes, leading to a relatively lower rate of several obstetrical outcomes. Due to the missing information in our dataset, we were not able to separate out iatrogenic preterm birth nor adjust for obstetric complications in previous pregnancies as a confounder in the mutivariate analysis. Because the days of blastocyst culture in total were unclear in our dataset, analysis of the association between the time to reach blastocyst expansion and perinatal outcomes was not performed.

WIDER IMPLICATIONS OF THE FINDINGS

Transfer of a blastocyst with a low overall grading is associated with a higher rate of C-section and a higher chance of a female baby. The association between ICM grading and LGA would suggest that Grade A ICM blastocysts should be transferred preferentially to Grade B/C ICM blastocysts. Our results support the use of current morphological systems for embryo prioritization.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by the National Key Research and Development Program of China (2018YFC1004100 to R.L.), the National Science Fund for Distinguished Young Scholars (81925013 to R.L.) and a Zhejiang University Scholarship for Outstanding Doctoral Candidates (to K.-L.H.). All authors have read the journal's authorship agreement and policy on disclosure of potential conflicts of interest, and have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Analysis of Biochemical and Clinical Pregnancy Loss Between Frozen-Thawed Embryo Transfer of Blastocysts and Day 3 Cleavage Embryos in Young Women: A Comprehensive Comparison

BACKGROUND

To determine whether the embryo developmental stage affects biochemical or clinical pregnancy loss in young women undergoing frozen-thawed embryo transfer (FET) and to investigate the underlying mechanism.

METHODS

This was a retrospective study including a total of 18,34 β-HCG (human chorionic gonadotropin)-positive FET cycles. According to the morphological appearance (MA) of transferred blastocysts, FET cycles with blastocysts were divided into two groups: Group A: morphologically good (MG) blastocysts only, and Group B: at least one morphologically non-good (MNG) blastocyst. FET cycles with day 3 cleavage embryos were assigned as Group C. Biochemical and clinical pregnancy loss were the main outcome measures.

RESULTS

We predicted 78% in vivo-formed MG and 53.9% in vivo-formed day 5 blastocysts in Group C. (a) Including cases in Group A and Group B for binary logistic regression, we showed that Group B and day 6 blastocysts had significantly higher rates of BPL and CPL than Group A and day 5 blastocysts, respectively. (b) Including cases in Group A, Group B, and Group C for binary logistic regression, we showed that Group C had a significantly higher rate of BPL than Group A and day 5 blastocysts and a similar rate of BPL as Group B and day 6 blastocysts. Group C had a higher rate of CPL than Group A (p=0.071) and day 5 blastocysts (p=0.039), and a lower rate of CPL than Group B (p=0.199) and day 6 blastocysts (p=0.234).

CONCLUSIONS

(1) MA and days of usable blastocysts could serve as independent factors affecting the occurrence of BPL and CPL. (2) Transfer of day 3 cleavage embryos may produce "unusable blastocysts" in vivo, which significantly increased the rate of BPL. (3) The rate of CPL resulting from the transfer of day 3 embryos may depend on the rate of in vivo-formed MG or day 5 blastocysts. Our study indicated that the difference in the BPL or CPL between transfer of blastocysts and day 3 cleavage embryos may largely depend on the quality of embryos transferred.