Number of embryos for transfer following in vitro fertilisation or intra-cytoplasmic sperm injection

Effect of GnRH agonist down-regulation combined with hormone replacement treatment on reproductive outcomes of frozen blastocyst transfer cycles in women of different ages

Objective

To investigate the effect of GnRH agonist (GnRH-a) down-regulation prior to hormone replacement treatment (HRT) to prepare the endometrium in frozen embryo transfer (FET) cycles in women of different ages.

Methods

This was a retrospective study, and after excluding patients with adenomyosis, endometriosis, severe endometrial adhesions, polycystic ovary syndrome (PCOS), and repeated embryo implantation failures, a total of 4,091 HRT cycles were collected. Patients were divided into group A (<35 years old) and group B (≥35 years old), and each group was further divided into HRT and GnRHa-HRT groups. The clinical outcomes were compared between groups.

Results

There was no statistically significant difference in clinical outcomes between the HRT and GnRHa-HRT groups among women aged <35 years. In women of advanced age, higher rates of clinical pregnancy and live birth were seen in the GnRHa-HRT group. Logistic regression analysis showed that female age and number of embryos transferred influenced the live birth rate in FET cycles, and in women aged ≥ 35 years, the use of GnRH-a down-regulation prior to HRT improved pregnancy outcomes.

Conclusions

In elderly woman without adenomyosis, endometriosis, PCOS, severe uterine adhesions, and RIF, hormone replacement treatment with GnRH agonist for pituitary suppression can improve the live birth rate of FET cycles.

Competent blastocyst and receptivity endometrium improved clinical pregnancy in fresh embryo transfer cycles: a retrospective cohort study

BACKGROUND

Embryo quality is usually regarded as a key predictor of successful implantation and clinical pregnancy potential. The identification of embryos that have the capacity to implant and result in a healthy pregnancy is a crucial part of in vitro fertilization (IVF). Usually, morphologically high-quality embryos are chosen for embryo transfer in IVF treatment. The aim of this study was to assess the association between the available blastocyst formation rate and the clinical pregnancy outcome following the first fresh embryo transfer cycle and provide systematic individual treatment to adjust endometrial receptivity for the next transfer cycle.

METHODS

This retrospective, single-center study included 512 fresh embryo transfers conducted between 11/2019 and 08/2021, which consisted of 385 cleavage-stage (Day 3) and 127 blastocyst-stage (Day 5) embryo transfers. The two groups were divided into a clinical pregnancy group and a nonclinical pregnancy group for comparison. The association between the available blastocyst formation rate and the clinical pregnancy rate in the Day 3 and Day 5 transfer groups were considered.

RESULTS

In the Day 3 group, there were 275 clinical pregnancies, and the clinical pregnancy rate was 71.43%. Although the two pronuclei (2PN) oocyte rate and available embryo rate at Day 3 were significantly higher in the clinical pregnancy group than the nonclinical pregnancy group (P < 0.05), the blastocyst formation rate and the available blastocyst formation rate were not significantly different between the clinical pregnancy group and the nonclinical pregnancy group (P > 0.05). In the Day 5 group, there were 81 clinical pregnancies, and the clinical pregnancy rate was 63.78%. No baseline characteristics showed any obvious differences between the clinical pregnancy group and nonclinical pregnancy group (P > 0.05). The blastocyst formation rate in the nonclinical pregnancy group was higher than that in the clinical pregnancy group, but the difference was not statistically significant (81.06% vs. 77.03%, P = 0.083). Interestingly, the available blastocyst formation rate and the Day 5 available blastocyst formation rate were significantly higher in the nonclinical pregnancy group than the clinical pregnancy group (66.19% vs. 60.79%, P = 0.014; 54.58% vs. 46.98%, P = 0.007).

CONCLUSIONS

In fresh cycles, the available blastocyst formation rate was not associated with the clinical pregnancy outcome for Day 3 embryo transfers, and the available blastocyst formation rate was not positively correlated with the clinical pregnancy outcome for Day 5 embryo transfers.

Predictors of twin pregnancy in in vitro fertilization with intracytoplasmic sperm injection cycles with day 3 double embryo transfer

OBJECTIVE

The purpose of this study was to identify factors associated with twin pregnancy following day 3 double embryo transfer (DET).

METHODS

This retrospective cohort study incorporated data from 16,972 day 3 DET cycles. The participants were women aged between 18 and 45 years who underwent in vitro fertilization with intracytoplasmic sperm injection (IVF/ICSI) at My Duc Assisted Reproduction Technique Unit (IVFMD), My Duc Hospital, located in Ho Chi Minh City, Vietnam.

RESULTS

Of the 16,972 day 3 DET cycles investigated, 8,812 (51.9%) resulted in pregnancy. Of these, 6,108 cycles led to clinical pregnancy, with 1,543 (25.3% of clinical pregnancies) being twin pregnancies. Factors associated with twin pregnancy included age under 35 years (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.32 to 1.71; p<0.001) and cycles involving the transfer of at least one grade I embryo. Relative to the transfer of two grade III embryos, the risk of twin pregnancy was significantly elevated following the transfer of two grade I embryos (OR, 1.40; 95% CI, 1.16 to 1.69; p<0.001) or a combination of one grade I and one grade II embryo (OR, 1.27; 95% CI, 1.05 to 1.55; p=0.001).

CONCLUSION

By analyzing a large number of IVF/ICSI cycles, we identified several predictors of twin pregnancy. These findings can assist medical professionals in tailoring treatment strategies for couples with infertility.

Long-term health risk of offspring born from assisted reproductive technologies

Since the world's first in vitro fertilization baby was born in 1978, there have been more than 8 million children conceived through assisted reproductive technologies (ART) worldwide, and a significant proportion of them have reached puberty or young adulthood. Many studies have found that ART increases the risk of adverse perinatal outcomes, including preterm birth, low birth weight, small size for gestational age, perinatal mortality, and congenital anomalies. However, data regarding the long-term outcomes of ART offspring are limited. According to the developmental origins of health and disease theory, adverse environments during early life stages may induce adaptive changes and subsequently result in an increased risk of diseases in later life. Increasing evidence also suggests that ART offspring are predisposed to an increased risk of non-communicable diseases, such as malignancies, asthma, obesity, metabolic syndrome, diabetes, cardiovascular diseases, and neurodevelopmental and psychiatric disorders. In this review, we summarize the risks for long-term health in ART offspring, discuss the underlying mechanisms, including underlying parental infertility, epigenetic alterations, non-physiological hormone levels, and placental dysfunction, and propose potential strategies to optimize the management of ART and health care of parents and children to eliminate the associated risks. Further ongoing follow-up and research are warranted to determine the effects of ART on the long-term health of ART offspring in later life.

Effect of frozen-thawed embryo transfer with a poor-quality embryo and a good-quality embryo on pregnancy and neonatal outcomes

BACKGROUND

To evaluate the impact of embryo quality and quantity, specifically a poor quality embryo (PQE) in combination with a good quality embryo (GQE), by double embryo transfer (DET) on the live birth rate (LBR) and neonatal outcomes in patients undergoing frozen-thawed embryo transfer (FET) cycles.

METHODS

A study on a cohort of women who underwent a total of 1462 frozen-thawed cleavage or blastocyst embryo transfer cycles with autologous oocytes was conducted between January 2018 and December 2021. To compare the outcomes between single embryo transfer (SET) with a GQE and DET with a GQE and a PQE, propensity score matching (PSM) was applied to control for potential confounders, and a generalized estimating equation (GEE) model was used to determine the association between the effect of an additional PQE and the outcomes. Subgroup analysis was also performed for patients stratified by female age.

RESULTS

After PS matching, DET-GQE + PQE did not significantly alter the LBR (adjusted odds ratio [OR] 1.421, 95% CI 0.907-2.228) compared with SET-GQE in cleavage-stage embryo transfer but did increase the multiple birth rate (MBR, [OR] 3.917, 95% CI 1.189-12.911). However, in patients who underwent blastocyst-stage embryo transfer, adding a second PQE increased the live birth rate by 7.8% ([OR] 1.477, 95% CI 1.046-2.086) and the multiple birth rate by 19.6% ([OR] 28.355, 95% CI 3.926-204.790), and resulted in adverse neonatal outcomes. For patients who underwent cleavage-stage embryo transfer, transferring a PQE with a GQE led to a significant increase in the MBR ([OR] 4.724, 95% CI 1.121-19.913) in women under 35 years old but not in the LBR ([OR] 1.227, 95% CI 0.719-2.092). The increases in LBR and MBR for DET-GQE + PQE compared with SET-GQE in women older than 35 years were nonsignificant toward. For patients who underwent blastocyst-stage embryo transfer, DET-GQE + PQE had a greater LBR ([OR] 1.803, 95% CI 1.165-2.789), MBR ([OR] 24.185, 95% CI 3.285-178.062) and preterm birth rate (PBR, [OR] 4.092, 95% CI 1.153-14.518) than did SET-GQE in women under 35 years old, while no significant impact on the LBR ([OR] 1.053, 95% CI 0.589-1.884) or MBR (0% vs. 8.3%) was observed in women older than 35 years.

CONCLUSIONS

The addition of a PQE has no significant benefit on the LBR but significantly increases the MBR in patients who underwent frozen-thawed cleavage-stage embryo transfer. However, for patients who underwent blastocyst-stage embryo transfer, DET-GQE + PQE resulted in an increase in both the LBR and MBR, which may lead to adverse neonatal outcomes. Thus, the benefits and risks of double blastocyst-stage embryo transfer should be balanced. In patients younger than 35 years, SET-GQE achieved satisfactory LBR either in cleavage-stage embryo transfer or blastocyst-stage embryo transfer, while DET-GQE + PQE resulted in a dramatically increased MBR. Considering the low LBR in women older than 35 years who underwent single cleavage-stage embryo transfer, selective single blastocyst-stage embryo transfer appears to be a more promising approach for reducing the risk of multiple live births and adverse neonatal outcomes.

Single versus double blastocyst transfer in first and second frozen-thawed embryo transfer cycle in advance-aged women: a two-center retrospective cohort study

BACKGROUND

The present evidence is deficient for the trade-offs between the pros and cons of single blastocyst transfer (SBT) versus double blastocyst transfer (DBT) in frozen-thawed embryo transfer cycles for women in advanced reproductive age, especially in the second cycle. The current study aimed to investigate the impact of transferred blastocyst numbers on pregnancy outcomes in the first and second embryo transfer for women ≥ 35 years.

METHODS

This was a retrospective cohort study including 1284 frozen-thawed blastocyst transfer (FBT) cycles from two reproductive centers. We analyzed the pregnancy outcomes after SBT and DBT in the first and second FBT cycles. Moreover, stratified analysis was conducted by maternal age.

RESULTS

In the first FBT cycle, the LBR was higher in the DBT group than that in the SBT group [52.3% vs. 33.9%; adjusted odds ratio (aOR), 1.65; 95% confidence interval (CI), 1.26-2.15, P < 0.001]. However, the LBR of the DBT group showed no remarkable difference compared with that of the SBT group in the second cycle of FBT (44.3% vs. 33.3%; aOR, 1.30; 95% CI, 0.81-2.08; P = 0.271). Furthermore, stratified analysis by age showed a higher LBR for the DBT group than the SBT group in patients aged 38-42 years (43.1% vs. 33.9%; aOR, 2.27; 95% CI, 1.05-4.90; P = 0.036).

CONCLUSIONS

The present study demonstrated that the SBT regimen is a better choice for both, the first and second frozen-thawed embryo transfer cycles, for women aged 35-37 years. Additionally, the DBT regimen is still recommended to achieve a high LBR in women aged 38-42 years in the second FBT cycle. These findings may be beneficial for deciding the embryo transfer regimens in women of advanced reproductive age.

Efficacy and safety of follitropin delta versus follitropin alpha/beta in infertility treatment: A systematic review and meta-analysis

Background

Follitropin δ may be an alternative to conventional follitropin α/β for controlled ovarian stimulation (COS) within assisted reproductive treatment (ART), but its efficacy and safety remain unknown. We performed a random-effects meta-analysis to compare the efficacy and safety of follitropin δ and follitropin α/β.

Methods

We searched randomized controlled trials comparing follitropin δ and follitropin α/β using MEDLINE, Embase, CENTRAL, ClinicalTrials.gov, and WHO-ITCRP on December 14, 2022. The primary outcomes were the live birth rate and the incidence of moderate or severe ovarian hyperstimulation syndrome (OHSS). The certainty of the evidence was assessed using the grading of recommendations assessment, development, and evaluation approach. The protocol was registered on the Open Science Framework.

Results

Three studies involving 2682 participants were included in our meta-analysis. The results indicated that follitropin δ may result in little to no difference in live birth rates (risk ratio [RR], 1.12; 95% confidence interval [CI], 0.91-1.38; low certainty) and the incidence of moderate or severe OHSS (RR, 0.78; 95% CI, 0.48-1.26; low certainty) compared with follitropin α/β.

Conclusion

Follitropin δ may result in little to no difference in COS compared with follitropin α/β, especially in terms of live births and safety.

An appraisal of current embryo transfer strategies

Embryo transfer, one of the most essential procedures in assisted reproductive technology, plays a vital role in the success of in-vitro fertilization and intracytoplasmic sperm injection. During the last decades, the strategies for embryo transfer have changed dramatically. In this review, we evaluate the efficacy and safety of several current embryo transfer strategies including fresh versus frozen embryo transfer, cleavage- versus blastocyst-stage embryo transfer, and single- versus double-embryo transfer. Available evidence indicates that the freeze-only strategy improves the live birth rate after the first embryo transfer in high responders while making no difference in normal responders. The risk of ovarian hyperstimulation syndrome is significantly reduced in the freeze-only strategy. Fresh blastocyst-stage embryo transfer increased live birth rate compared to cleavage-stage embryo transfer. The best embryo transfer strategy is one which tailors to individual circumstances and preferences.

Acceptance of Elective Single-embryo Transfer in a Resource-limited Setting: A Cross-sectional Questionnaire-based Study

Background

While elective single-embryo transfer (eSET) has been advocated in select countries, the global acceptance of the eSET policy has been undermined due to various issues. It is imperative to understand the couples' perspectives regarding the number of embryos transferred.

Aims

We planned a study to evaluate the knowledge and attitude of infertile couples undergoing assisted reproductive technology towards eSET in self-funded treatment cycles in a low-resource setting.

Settings and Design

We conducted a cross-sectional study at a tertiary-level referral facility between February 2020 and September 2022.

Materials and Methods

This was an interviewer-administered questionnaire-based survey in two stages. The first stage involved the assessment of the knowledge of the participants. Following this, participants were given an information pamphlet and the second stage of the interview was conducted to assess the attitude and change in preference for embryo transfer number.

Statistical Analysis Used

The Chi-square and Fisher's exact test were applied to find an association between categorical variables. Logistic regression was used to assess the association between factors and outcomes.

Results

eSET was the preferred choice for only 5.8% of the participants. Following our educational intervention using an information leaflet, there was a statistically significant increase in the preference for eSET (P = 0.01). Univariate logistic regression analysis revealed that participants with a monthly income of ≤50,000 INR had a significantly higher preference for eSET.

Conclusion

Continued emphasis on the risks of double-embryo transfer coupled with individualised selection criteria for eSET may help to achieve reasonable congruency between the clinician and couples' decision.

Evidence-Based Pre-Pregnancy Counseling for Oocyte Donation Pregnancies: a Systematic Review and Guide for Physicians

It is well known that oocyte donation (OD) pregnancies are associated with higher complication rates compared to autologous pregnancies. However, evidence-based information for pre-pregnancy counseling designed for health care workers is scarce. Therefore, a systematic literature search was performed to find articles that address pre-pregnancy counseling before OD.A systematic search was conducted in September 2020 in various databases, including PubMed and Embase. Nine (systematic) reviews and meta-analyses were included that reported on pre-pregnancy advice in OD pregnancies.Studies are consistent in documenting a higher risk for hypertensive disorders, cesarean section, preterm birth, postpartum hemorrhage, and low birth weight. Based on these complications, pre-pregnancy advice is mentioned in all included systematic reviews to prevent complications in the next pregnancy. All studies recommend counseling women on the increased risk of complications during OD pregnancy. Other recommendations include the prophylactic use of aspirin in pregnancy and restriction to single embryo transfer. Individualized appropriate surveillance and management strategies should be considered for every patient achieving pregnancy by OD.In conclusion, we provide a summary of the most important outcomes in OD pregnancies, and thereby offer a guide for pre-pregnancy counseling.

The Application of Artificial Intelligence in Predicting Embryo Transfer Outcome of Recurrent Implantation Failure

Background: Recurrent implantation failure (RIF) refers to that infertile patients have undergone multiple in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles and transferred multiple embryos without embryo implantation or clinical pregnancy. Due to the lack of clear evidence-based medical guidelines for the number of embryos to be transferred in RIF patients, how to obtain the highest single cycle pregnancy success rate with as few embryos transferred as possible while avoiding multiple pregnancy as much as possible, that is, how to balance the pregnancy success rate and multiple pregnancy rate, is a great challenge for clinicians and RIF patients. We urgently need an effective and reliable assisted decision-making method to help clinicians find this balance, and an artificial intelligence (AI) system will provide an efficient solution.

Design and Methods: In this research, we filtered out the RIF data set (n = 45,921) from the Human Fertilisation and Embryology Authority (HFEA) database from 2005 to 2016. The data set was divided into two groups according to the number of embryos transferred, Group A and B. Group A included 34,175 cycles with two embryos transferred, while Group B included 11,746 cycles with only one embryo transferred, each containing 44 features and a prediction label (pregnancy). Four machine learning algorithms (RF, GBDT, AdaBoost, and MLP) were used to train Group A and Group B data set respectively and 10-folder cross validation method was used to validate the models.

Results: The results revealed that the AdaBoost model of Group A obtained the best performance, while the GBDT model in Group B was proved to be the best model. Both models had been proved to provide accurate prediction of transfer outcome.

Conclusion: Our research provided a new approach for targeted and personalized treatment of RIF patients to help them achieve efficient and reliable pregnancy. And an AI-assisted decision-making system will be designed to help clinicians and RIF patients develop personalized transfer strategies, which not only guarantees efficient and reliable pregnancy, but also avoids the risk of multiple pregnancy as much as possible.

Cleavage-stage versus blastocyst-stage embryo transfer in assisted reproductive technology

BACKGROUND

Advances in embryo culture media have led to a shift in in vitro fertilisation (IVF) practice from cleavage-stage embryo transfer to blastocyst-stage embryo transfer. The rationale for blastocyst-stage transfer is to improve both uterine and embryonic synchronicity and enable self selection of viable embryos, thus resulting in better live birth rates.

OBJECTIVES

To determine whether blastocyst-stage (day 5 to 6) embryo transfer improves the live birth rate (LBR) per fresh transfer, and other associated outcomes, compared with cleavage-stage (day 2 to 3) embryo transfer.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group Specialised Register of controlled trials, CENTRAL, MEDLINE, Embase, PsycINFO, and CINAHL, from inception to October 2021. We also searched registers of ongoing trials and the reference lists of studies retrieved.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) which compared the effectiveness of IVF with blastocyst-stage embryo transfer versus IVF with cleavage-stage embryo transfer.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. Our primary outcomes were LBR per fresh transfer and cumulative clinical pregnancy rates (cCPR). Secondary outcomes were clinical pregnancy rate (CPR), multiple pregnancy, high-order multiple pregnancy, miscarriage (all following first embryo transfer), failure to transfer embryos, and whether supernumerary embryos were frozen for transfer at a later date (frozen-thawed embryo transfer). We assessed the overall quality of the evidence for the main comparisons using GRADE methods.

MAIN RESULTS

We included 32 RCTs (5821 couples or women). The live birth rate following fresh transfer was higher in the blastocyst-stage transfer group (odds ratio (OR) 1.27, 95% confidence interval (CI) 1.06 to 1.51; I² = 53%; 15 studies, 2219 women; low-quality evidence). This suggests that if 31% of women achieve live birth after fresh cleavage-stage transfer, between 32% and 41% would do so after fresh blastocyst-stage transfer. We are uncertain whether blastocyst-stage transfer improves the cCPR. A post hoc analysis showed that vitrification could increase the cCPR. This is an interesting finding that warrants further investigation when more studies using vitrification are published. The CPR was also higher in the blastocyst-stage transfer group, following fresh transfer (OR 1.25, 95% CI 1.12 to 1.39; I² = 51%; 32 studies, 5821 women; moderate-quality evidence). This suggests that if 39% of women achieve a clinical pregnancy after fresh cleavage-stage transfer, between 42% and 47% will probably do so after fresh blastocyst-stage transfer. We are uncertain whether blastocyst-stage transfer increases multiple pregnancy (OR 1.05, 95% CI 0.83 to 1.33; I² = 30%; 19 studies, 3019 women; low-quality evidence) or miscarriage rates (OR 1.12, 95% CI 0.90 to 1.38; I² = 24%; 22 studies, 4208 women; low-quality evidence). This suggests that if 9% of women have a multiple pregnancy after fresh cleavage-stage transfer, between 8% and 12% would do so after fresh blastocyst-stage transfer. However, a sensitivity analysis restricted only to studies with low or 'some concerns' for risk of bias, in the subgroup of equal number of embryos transferred, showed that blastocyst transfer probably increases the multiple pregnancy rate. Embryo freezing rates (when there are frozen supernumerary embryos for transfer at a later date) were lower in the blastocyst-stage transfer group (OR 0.48, 95% CI 0.40 to 0.57; I² = 84%; 14 studies, 2292 women; low-quality evidence). This suggests that if 60% of women have embryos frozen after cleavage-stage transfer, between 37% and 46% would do so after blastocyst-stage transfer. Failure to transfer any embryos was higher in the blastocyst transfer group (OR 2.50, 95% CI 1.76 to 3.55; I² = 36%; 17 studies, 2577 women; moderate-quality evidence). This suggests that if 1% of women have no embryos transferred in planned fresh cleavage-stage transfer, between 2% and 4% probably have no embryos transferred in planned fresh blastocyst-stage transfer. The evidence was of low quality for most outcomes. The main limitations were serious imprecision and serious risk of bias, associated with failure to describe acceptable methods of randomisation.

AUTHORS' CONCLUSIONS

There is low-quality evidence for live birth and moderate-quality evidence for clinical pregnancy that fresh blastocyst-stage transfer is associated with higher rates of both than fresh cleavage-stage transfer. We are uncertain whether blastocyst-stage transfer improves the cCPR derived from fresh and frozen-thawed cycles following a single oocyte retrieval. Although there is a benefit favouring blastocyst-stage transfer in fresh cycles, more evidence is needed to know whether the stage of transfer impacts on cumulative live birth and pregnancy rates. Future RCTs should report rates of live birth, cumulative live birth, and miscarriage. They should also evaluate women with a poor prognosis to enable those undergoing assisted reproductive technology (ART) and service providers to make well-informed decisions on the best treatment option available.

The clinical outcomes of selective and spontaneous fetal reduction of twins to a singleton pregnancy in the first trimester: a retrospective study of 10 years

BACKGROUND

Singleton pregnancy is encouraged to reduce pregnancy complications. In addition to single embryo transfer (SET), selective and spontaneous fetal reduction (SEFR and SPFR) can also achieve singleton pregnancies. After SEFR or SPFR, an inanimate fetus remains in the uterus. It is unclear whether the inanimate fetus would adversely affect another fetus or the mother. Previous studies have focused on the differences between pre- and post-reduction. However, studies focusing on the influence of SEFR and SPFR on the remaining fetal development and maintenance of pregnancy are rare.

METHODS

Materials from 5922 patients whose embryo transfer dates ranged from March 2011 to January 2021 were collected. Both the SEFR group (n = 390) and SPFR group (n = 865) had double embryos transferred (DET) and got twin pregnancies, but subsequent selective or spontaneous fetal reduction occurred. The SET group (n = 4667) had only one embryo transferred. All were singleton pregnancies on the 65th day after embryo transfer. Clinical outcomes, including pregnancy outcomes, pregnancy complications, and newborn outcomes, were compared among the three groups.

RESULTS

After adjusting for age, infertility duration, types of infertility, states of embryos, body mass index, and factors affecting SET or DET decisions, multivariate regression analysis revealed that SEFR increased the risk of miscarriage (OR 2.368, 95% CI 1.423-3.939) and preterm birth (OR 1.515, 95% CI 1.114-2.060), and reduced the gestational age (βeta -0.342, 95% CI -0.544- -0.140). SPFR increased the risk of gestational diabetes mellitus (GDM) (OR 1.657, 95% CI 1.215-2.261), preterm premature rupture of membranes (PPROM) (OR 1.649, 95% CI 1.057-2.574), and abnormal amniotic fluid volume (OR 1.687, 95% CI 1.075-2.648). Both SEFR and SPFR were associated with reduced live birth rate (OR 0.522, 95% CI 0.330-0.825; OR 0.671, 95% CI 0.459-0.981), newborn birth weight (βeta -177.412, 95% CI -235.115--119.709; βeta -42.165, 95% CI -83.104--1.226) as well as an increased risk of low-birth-weight newborns (OR 2.222, 95% CI 1.490-3.313; OR 1.510, 95% CI 1.092-2.087).

CONCLUSIONS

DET with subsequent fetal reduction was related to poor clinical outcomes. We recommend that DET with subsequent fetal reduction should only be considered as a rescue method for multiple pregnancy patients with potential complications, and SET is more advisable.

Risk factors for twin pregnancy in women undergoing double cleavage embryo transfer

Background

Two or more embryo transfers have been used to increase the success rate of live birth in traditional in vitro fertilization (IVF) strategy at the expense of increased risks of multiple pregnancy and adverse perinatal outcomes. The decision regarding the elective single embryo transfer or double embryo transfer remains inconclusive. The aim of this study was to investigate the risk factors for twin pregnancy in IVF.

Methods

Participants who underwent their first fresh IVF cycle where two cleavage stage embryos were transferred in Women’s Hospital of Zhejiang University between January 2010 and December 2018 were included in this retrospective cohort study. The primary outcome was twin delivery. Secondary outcomes included preterm birth and low birth weight

Results

Fifteen thousand four hundred fifty-nine women were available for final analysis, in which 1511 women resulted in twin delivery and 4788 women had singleton delivery. Female age over 35 was associated with reduced rates of twin pregnancy compared with female age at or less than 35 (9.5% vs 25.1%, aRR = 0.38 (0.27. 0.55)). Poor-type endometrium was associated with reduced rates of twin pregnancy (19.2% vs 27.5%, aRR = 0.75 (0.58. 0.96)). Two good-quality embryos for transfer was associated with significantly higher rates of twin pregnancy compared with one good-quality or none good-quality embryo (26% vs 12.8% vs 9.3%, aRR = 0.56 (0.45. 0.70), aRR = 0.44(0.26. 0.74)). Female age over 35 and none or one good-quality embryo for transfer were associated with reduced rate of low birth weight and preterm birth.

Conclusion

Women with age over 35, poor-type endometrium, one good-quality embryo or none good-quality embryo were associated with reduced rate for twin pregnancy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04606-1.

Effectiveness and Safety of Two Consecutive Cycles of Single Embryo Transfer Compared With One Cycle of Double Embryo Transfer: A Systematic Review and Meta-Analysis

OBJECTIVE

To date, evidence regarding the effectiveness and safety of two consecutive cycles of single embryo transfer (2SETs) compared with one cycle of double embryo transfer (DET) has been inadequate, particularly considering infertile women with different prognostic factors. This study aimed to comprehensively summarize the evidence by comparing 2SETs with DET.

METHODS

PubMed, Embase, Cochrane Library databases, ClinicalTrails.gov, and the WHO International Clinical Trials Registry Platform were searched up to March 22, 2022. Peer-reviewed, English-language randomized controlled trials (RCTs) and observational studies (OS) comparing the outcomes of 2SETs with DET in infertile women with their own oocytes and embryos were included. Two authors independently conducted study selection, data extraction, and bias assessment. The Mantel-Haenszel random-effects model was used for pooling RCTs, and a Bayesian design-adjusted model was conducted to synthesize the results from both RCTs and OS.

MAIN RESULTS

Twelve studies were finally included. Compared with the DET, 2SETs were associated with a similar cumulative live birth rate (LBR; 48.24% vs. 48.91%; OR, 0.97; 95% credible interval (CrI), 0.89-1.13, τ^{2 =} 0.1796; four RCTs and six observational studies; 197,968 women) and a notable lower cumulative multiple birth rate (MBR; 0.87% vs. 17.72%; OR, 0.05; 95% CrI, 0.02-0.10, τ^{2 =} 0.1036; four RCTs and five observational studies; 197,804 women). Subgroup analyses revealed a significant increase in cumulative LBR (OR, 1.33; 95% CrI, 1.29-1.38, τ^{2 =} 0) after two consecutive cycles of single blastocyst transfer compared with one cycle of double blastocyst transfer. Moreover, a lower risk of cesarean section, antepartum hemorrhage, preterm birth, low birth weight, and neonatal intensive care unit admission but a higher gestational age at birth and birth weight were found in the 2SETs group.

CONCLUSION

Compared to the DET strategy, 2SETs result in a similar LBR while simultaneously reducing the MBR and improving maternal and neonatal adverse outcomes. The 2SETs strategy appears to be especially beneficial for women aged ≤35 years and for blastocyst transfers.

Maternal and neonatal outcomes following in vitro fertilization: A cohort study in Romania

Although in recent years the number of pregnancies obtained through in vitro fertilization (IVF) has increased significantly, a higher incidence of complications has been identified in this group. The widespread development and use of IVF has led to an increasing rate of multiple pregnancies and thus their associated complications. However, whether these complications occur due to assisted reproduction or infertility problems remains to be elucidated. In the present study, a comparison was made of IVF pregnancies with spontaneous conception, and the risk of obstetric and neonatal complications was assessed. An ambispective observational cohort study was carried out between January 2017 and October 2021 at Elias University Emergency Hospital, Romania. The exposed cohort included 132 IVF pregnancies and the control cohort included 157 spontaneous pregnancies. The IVF group included 110 pregnancies with fresh embryo-transfer and 22 pregnancies with cryopreserved embryo-transfer. Obstetric, perinatal and neonatal complications were analysed by multivariable logistic analysis. The results showed that, IVF pregnancies had a higher risk of pregnancy-induced hypertension (OR=6.42, 95% CI=1.72-23.92) and placental abnormalities (OR=5.49, 95% CI=1.07-28.17). Neonates obtained through IVF had a higher risk of prematurity (OR=6.52, 95% CI=2.99-14.20), low birth weight (LBW) (OR=17.18, 95% CI=7.06-41.87), small for gestational age (OR=4.10, 95% CI=1.95-8.59) and were more frequently hospitalized in the Neonatal Intensive Care Unit (NICU) (OR=11.91, 95% CI=5.72-24.81). Nulliparous women were associated with an increased risk of NICU admission (OR=0.46, 95% CI=0.25-0.88) and risk of LBW (OR=0.37, 95% CI=0.19-0.75). Maternal age ≥35 years had no influence as a confounding variable. In conclusion, this cohort study showed that IVF pregnancies have a higher risk of obstetric and neonatal complications than pregnancies obtained by spontaneous conception.

PGT-A: who and when? Α systematic review and network meta-analysis of RCTs

PURPOSE

Wide controversy is still ongoing regarding efficiency of preimplantation genetic testing for aneuploidy (PGT-A). This systematic review and meta-analysis, aims to identify the patient age group that benefits from PGT-A and the best day to biopsy.

METHODS

A systematic search of the literature was performed on MEDLINE/PubMed, Embase and Cochrane Central Library up to May 2020. Eleven randomized controlled trials employing PGT-A with comprehensive chromosomal screening (CCS) on Day-3 or Day-5 were eligible.

RESULTS

PGT-A did not improve live-birth rates (LBR) per patient in the general population (RR:1.11; 95%CI:0.87-1.42; n=1513; I2=75%). However, PGT-A lowered miscarriage rate in the general population (RR:0.45; 95%CI:0.25-0.80; n=912; I2=49%). Interestingly, the cumulative LBR per patient was improved by PGT-A (RR:1.36; 95%CI:1.13-1.64; n=580; I2=12%). When performing an age-subgroup analysis PGT-A improved LBR in women over the age of 35 (RR:1.29; 95%CI:1.05-1.60; n=692; I2=0%), whereas it appeared to be ineffective in younger women (RR:0.92; 95%CI:0.62-1.39; n=666; I2=75%). Regarding optimal timing, only day-5 biopsy practice presented with improved LBR per ET (RR: 1.37; 95% CI: 1.03-1.82; I2=72%).

CONCLUSION

PGT-A did not improve clinical outcomes for the general population, however PGT-A improved live-birth rates strictly when performed on blastocyst stage embryos of women over the 35-year-old mark.

Single-embryo transfer: a key strategy to reduce the risk for multiple pregnancy in assisted human reproduction

In the early days of assisted reproductive technology (ART), the main target was achieving gestation. Success rates were low, and multiple embryo transfers became common practice, with multiple pregnancies being 20 times higher than in natural conception. Multiple pregnancy is associated with a higher risk of complications for the mother and the baby than a singleton pregnancy. Added to healthcare costs, multiple pregnancy also involves other costs and psychosocial risks, with a high social and health costs. At present, success rates of assisted human reproduction (AHR) have improved dramatically, partially due to advances in laboratory techniques such as culture of blastocyst-stage embryos and vitrification. Additionally, there is a wide range of counseling, health and economic policies that have demonstrated being effective in increasing single-embryo transfer (SET) practices and reducing multiple pregnancies, which ensures satisfactory success rates. Therefore, single-embryo transfer emerges as the approach of choice for AHR to result in a full-term healthy newborn.

POSEIDON classification and the proposed treatment options for groups 1 and 2: time to revisit? A retrospective analysis of 1425 ART cycles

STUDY QUESTION

Do live birth outcomes differ when Patient-Oriented Strategy Encompassing IndividualizeD Oocyte Number (POSEIDON) stratified groups are compared with women with good prognosis (non-POSEIDON group) undergoing ART?

SUMMARY ANSWER

The current study showed no significant difference in the live birth rates (LBRs) per embryo transfer between POSEIDON groups 1 and 2 when compared with women in the non-POSEIDON group undergoing ART.

WHAT IS KNOWN ALREADY

Recently, there has been a lot of focus on the POSEIDON classification for low prognosis women undergoing ART and various management options have been advocated. For POSEIDON groups 1 and 2, low starting dose and gonadotrophin receptor polymorphism have been suggested as possible reasons for a hyporesponse, and increasing the starting gonadotrophin dose, the addition of recombinant LH and dual stimulation have been suggested as treatment options. Most of these treatment options are hypothetical in nature and need validation.

STUDY DESIGN SIZE DURATION

In the current cohort study, a total of 1425 cycles were analyzed retrospectively following a single cycle fresh embryo transfer. The study period was from January 2013 to June 2018.

PARTICIPANTS/MATERIALS SETTING METHODS

Women undergoing ART at a tertiary level infertility clinic were included. Clinical and treatment-related details were obtained from the hospital's electronic medical records. The ART outcomes in a non-POSEIDON group (women with an adequate ovarian reserve and/or optimal ovarian response i.e. >9 oocytes retrieved in the previous ART cycle) and a low prognosis group stratified by POSEIDON criteria were compared. We also examined the effectiveness of the modifications made in the current ART treatment protocols among women with an adequate ovarian reserve who had a history of poor/suboptimal response (POSEIDON 1 and 2).

MAIN RESULTS AND THE ROLE OF CHANCE

There was no statistically significant difference in the LBR per embryo transfer in POSEIDON group 1 (32/109, 29%) and group 2 (17/58, 29%) when compared with the non-POSEIDON group (340/1041, 33%) (adjusted odds ratio (aOR) 0.69; 95% CI 0.37-1.27 and aOR 0.93, 95% CI 0.43-1.97, respectively), while significantly lower LBR were observed in POSEIDON groups 3 (17/97, 17.5%) and 4 (12/120, 10%) (aOR 0.49; 95% CI 0.28-0.89 and aOR 0.38, 95% CI 0.19-0.74, respectively). The gonadotrophin dose alone was increased in one-quarter of the cycles and in another 27% the dose was increased along with the protocol change among POSEIDON group 1. In POSEIDON group 2, a change in the dose alone and in combination with protocol change was performed in 5 and 41% of cycles, respectively.

LIMITATIONS REASONS FOR CAUTION

A limitation of our study is the retrospective nature of the study with an inherent risk of unknown confounders influencing the outcomes. Other limitations are the lack of cumulative live birth data and the relatively small sample within POSEIDON group 2, which could lead to a type II error.

WIDER IMPLICATIONS OF THE FINDINGS

The current study showed no significant difference in the LBR between the POSEIDON groups 1 and 2 when compared with the non-POSEIDON group of women, while groups 3 and 4 had significantly lower LBR. The simple gonadotrophin/protocol changes in groups 1 and 2 resulted in LBRs comparable to women with good prognosis. These findings call for revisiting the proposed treatment strategies for POSEIDON groups 1 and 2.

STUDY FUNDING/COMPETING INTERESTS

No funding was obtained. There are no competing interests to declare.

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.