The likelihood of live birth and multiple birth after single versus double embryo transfer at the cleavage stage: a systematic review and meta-analysis

IAS-FET: An intelligent assistant system and an online platform for enhancing successful rate of in-vitro fertilization embryo transfer technology based on clinical features

BACKGROUND

Among all of the assisted reproductive technology (ART) methods, in vitro fertilization-embryo transfer (IVF-ET) holds a prominent position as a key solution for overcoming infertility. However, its success rate hovers at a modest 30% to 70%. Adding to the challenge is the absence of effective models and clinical tools capable of predicting the outcome of IVF-ET before embryo formation. Our study is dedicated to filling this critical gap by aiming to predict IVF-ET outcomes and ultimately enhance the success rate of this transformative procedure.

METHODS

In this retrospective study, infertile patients who received artificial assisted pregnancy treatment at Gansu Provincial Maternity and Child-care Hospital in China were enrolled from 2016 to 2020. Individual's clinical information were studied by cascade XGBoost method to build an intelligent assisted system for predicting the outcome of IVF-ET, called IAS-FET. The cascade XGBoost model was trained using clinical information from 2292 couples and externally tested using clinical information from 573 couples. In addition, several schemes which will be of help for patients to adjust their physical condition to improve their success rate on ART were suggested by IAS-FET.

RESULTS

The outcome of IVF-ET can be predicted by the built IAS-FET method with the area under curve (AUC) value of 0.8759 on the external test set. Besides, this IAS-FET method can provide several schemes to improve the successful rate of IVF-ET outcomes. The built tool for IAS-FET is addressed as a free platform online at http://www.cppdd.cn/ART for the convenient usage of users.

CONCLUSIONS

It suggested the significant influence of personal clinical features for the success of ART. The proposed system IAS-FET based on the top 27 factors could be a promising tool to predict the outcome of ART and propose a plan for the patient's physical adjustment. With the help of IAS-FET, patients can take informed steps towards increasing their chances of a successful outcome on their journey to parenthood.

Association between transferred embryos and multiple pregnancy/live birth rate in frozen embryo transfer cycles: A retrospective study

Background

Physicians need an appropriate embryo transfer strategy to address the challenge of reducing multiple birth rates, while maintaining the couples' live birth rate during assisted reproductive technology.

Methods

We included 10,060 frozen embryo transfer cycles from January 2015 to March 2020 in reproductive medical center of Ruijin hospital, Shanghai, China. Patients were grouped according to the number and grade of cleavage-stage embryo or blastocysts transferred. Live birth rate and multiple live birth rate were compared among groups of women of different ages. Multivariable logistic regression models were used to estimate the risk of multiple live birth using different combinations of transferred embryos.

Results

The transfer of double good-quality embryos was an independent predictor for multiple birth in women aged <30 years and those aged 36-39 years [<30 years: aOR =1.54 (95% CI: 1.14-2.06, P < 0.01); 36-39 years: aOR =1.84 (95% CI: 1.0-3.4, P < 0.01)]. Further, for women aged <36 years, the transfer of good-quality + poor-quality blastocysts was an independent predictor for multiple birth rate [<30 years: aOR=2.46 (95% CI: 1.45-4.18, P < 0.01); 31-35 years: aOR =4.45 (95% CI: 1.97-10.06, P < 0.01)].

Conclusions

Single-good-quality blastocyst transfer is recommended for women of all ages. When good-quality cleavage embryos are available, the choice of single or double embryo transfer with good- or average-quality embryo should depend on the age of women. Double embryo transfer with the highest possible grade of embryos is recommended for women aged ≥40 years.

Obstetric and Perinatal Outcomes of Singleton Births Following Single- vs Double-Embryo Transfer in Sweden

Importance

Pregnancies resulting from assisted reproductive technology are associated with an increased risk of adverse perinatal outcomes compared with those following natural conception. Previous studies have shown an association of pregnancies resulting from transfer of multiple embryos with these negative findings.

Objective

To determine the risk for adverse outcomes in singletons conceived through assisted reproduction using double-embryo transfer (DET) vs single-embryo transfer (SET).

Design, Setting, and Participants

This cohort study used data from women who achieved singleton deliveries after SET or DET in Sweden between 2007 and 2017 as recorded in the National Quality Registry for Assisted Reproduction. All embryo transfers, at cleavage or blastocyst stage, replaced in fresh or frozen treatment cycles were included. Data on obstetric and neonatal outcomes were retrieved by linkage to the National Medical Birth Register. Naturally conceived singletons were included as a reference group. Data were analyzed between September 2021 and August 2022.

Exposures

Double-embryo transfer leading to singleton birth.

Main Outcomes and Measures

Relative risk ratios or odds ratios (ORs) and absolute risk differences (ARDs) in percentage points with 95% CIs were calculated for obstetric and perinatal outcomes in singleton births conceived using DET vs SET.

Results

Among 1 115 863 singleton births, 30 713 singletons were born after SET and 5123 after DET. A higher risk of neonatal death was found in singletons after DET vs SET (OR, 2.67 [95% CI, 1.28-5.55]; ARD, 0.2 percentage points [95% CI, 0.0-0.4 percentage points]). In frozen embryo transfers, DET was associated with a higher risk of low birth weight (OR, 1.64 [95% CI, 1.19-2.25]; ARD, 2.0 percentage points [95% CI, 0.5-3.5 percentage points]). Among blastocyst transfers, DET was associated with very preterm birth (relative risk ratio, 2.64 [95% CI, 1.50-4.63]; ARD, 1.8 percentage points [95% CI, 0.3-3.4 percentage points]) and low birth weight (OR, 1.83 [95% CI, 1.29-2.60]; ARD, 3.2 percentage points [95% CI, 0.9-5.5 percentage points]).

Conclusions and Relevance

These results indicate a higher risk of adverse outcomes following DET, even when the result is a singleton birth, vs singletons born after SET. Adverse outcomes were mainly observed in singletons following DET using frozen embryos and blastocysts.

Higher baseline alanine aminotransferase level is associated with lower live birth rate after freeze-thawed embryo transfer

OBJECTIVE

The aim of this retrospective analysis was to explore whether an elevated ALT level before pregnancy is associated with a reduction in live birth rate after IVF-FET.

DESIGN

Retrospective observational study.

SETTING

Shiyan People's Hospital, China between January 2019 and December 2019.

PATIENTS

Women aged ≤ 40 years.

INTERVENTION(S)

Freeze-thawed embryo transfer (FET).

MAIN OUTCOME MEASURE(S)

The live birth rate, which was defined as the delivery of a live baby after 24 weeks of gestation.

RESULTS

The analysis included 365 FET cycles. There was a significant difference between groups in the live birth rate (p < .05), which was highest for the low ALT tertile and lowest for the high ALT tertile. Multiple regression analysis with adjustment for multiple potential confounders revealed that the odds of live birth were decreased for each one standard deviation increase in ALT (OR = 0.56, 95%CI = 0.42-0.75, p < .0001) and lower for the high ALT tertile than for the low ALT tertile (OR = 0.38, 95%CI = 0.19-0.75, p = .0055). Smooth curve fitting showed an inverse relationship between ALT and live birth rate.

CONCLUSION

Our findings indicate that relatively small elevations in baseline serum ALT level can have a clinically relevant impact on the success of FET.

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.

Pregnancy Outcomes Following the First Frozen Blastocyst Transfer Among Women Aged Less Than 35 Years Old: A Retrospective Cohort Study

Background: Many guidelines have been issued regarding the number of embryos to be transferred after in vitro fertilization (IVF), but patients and clinicians may be reluctant to accept or offer a single embryo transfer due to the expected lower chance of pregnancy or live birth. This study was aimed to provide additional information on cycle outcome according to the number and quality of thawed transferred blastocysts.

Methods: A retrospective cohort study was designed to collect the data of 505 patients who performed the first frozen blastocysts transfer at Tam Anh General Hospital from June 2018 to September 2019. One good-quality embryo was transferred for 121 patients (Group 1), two good for 214 patients (Group 2), one good and one poor for 112 patients (Group 3), one good and two poor for 25 patients (Group 4), and one or two poor for 33 patients (Group 5).

Results: The pregnancy rate was 71.9%, 74.8%, 69.4%, 84.0%, and 39.4% in Group 1–5, respectively. The multiple pregnancy rate was 36.9%, 16.9%, and 32.0% in Groups 2–4, respectively, higher than Group 1 (4.9%). The live birth rate was 55.6%, 50.9%, and 60.0% in Group 2–4, respectively, but not significantly different from the Group 1 (47.9%).

Conclusions: Transferring an additional good or poor embryo, along with a good embryo, does not increase the live birth rate while the incidence of multiple pregnancies rises significantly.

Association between baseline LH/FSH and live-birth rate after fresh-embryo transfer in polycystic ovary syndrome women

This study aimed to retrospectively analyse the effect of the baseline luteinising hormone/follicle-stimulating hormone ratio (bLH/FSH) on the live-birth rate per fresh-embryo transfer cycle (LBR/ET) in infertile women with polycystic ovary syndrome (PCOS) who received a fresh-embryo transfer. A total of 424 patients with PCOS who underwent the first cycle of in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) fresh-embryo transfer at our hospital was enrolled. Univariate and multivariate logistic regression analyses, along with curve fitting and a threshold effect analysis, were performed. Baseline LH/FSH levels were a significant (P < 0.05) independent risk factor affecting live birth. In the first IVF/ICSI antagonist treatment cycles, LBR/ET after fresh-embryo transfer was relatively flat, until bLH/FSH was 1.0; thereafter, it started to decrease by 17% for every 0.1-unit bLH/FSH increase. Considering the decline in LBR/ET, it is recommended that PCOS women with bLH/FSH > 1.0 carefully consider fresh-embryo transfer during their first IVF/ICSI.

The predictive value of endometrial thickness in 3117 fresh IVF/ICSI cycles for ectopic pregnancy

OBJECTIVES

To evaluate the predictive value of endometrial thickness (EMT) during in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles for ectopic pregnancy (EP).

METHODS

A total of 3068 patients with 3117 fresh IVF/ICSI cycles between January 2016 and February 2019 from the Reproductive Medicine Center of Sun Yat-Sen Memorial Hospital were included in this retrospective study. The patients were divided into an EP group (n = 92) and an intrauterine pregnancy (IUP) group (n = 3025). Multiple logistic regression analysis was conducted to evaluate the EP risk factors. Receiver operating characteristic (ROC) curves were used to evaluate the predictive value of the risk factors for EP and calculate the cutoff value of EMT for EP prediction.

RESULTS

The incidence rate of EP was 2.95 % (92/3117). After adjustment for other factors in the logistic regression model, the incidence of EP decreased by 55 % with an EMT > 10 mm compared with an EMT ≤ 10 mm (odds ratio 0.450, 95 % confidence interval 0.296-0.684, P < 0.001). The EMT in the EP group was significantly thinner than that in the live birth (n = 2540) and spontaneous abortion (n = 485) groups (p < 0.017). The cutoff value of EMT for EP prediction was 10.65 mm, with a sensitivity of 59 % and a specificity of 63 %.

CONCLUSION

A decreased risk of EP was found among the patients with an EMT > 10 mm prior to embryo transfer. A certain EMT is needed to reduce the incidence of EP.

The impact of a poor quality embryo on the implantation chance of a good quality one when transferred together: A study on double blastocyst transfers

OBJECTIVE

Embryo quality assessment with morphological evaluation remains the first-line method of assessment to select the best embryo for transfer. We aimed to determine if an effect of poor quality embryos on good quality ones exists, whether by a paracrine effect or an adverse endometrial influence, when they are transferred together.

MATERIALS AND METHODS

We included 412 couples, who underwent intracytoplasmic sperm injection (ICSI) cycles in a tertiary IVF center. Single embryo transfer with a good quality embryo and double embryo transfers with a good + poor quality embryo were evaluated. Overall pregnancy (PR) and live birth rates (LBR) were our main outcome measures.

RESULTS

When PR and LBR are compared, there was no statistical significance between single embryo transfer (SET) and double embryo transfer (DET) groups (51.7 % vs 53.7 %, p = 0.620 and 47 % vs 43.1 %, p = 0.117). When the PR and LBRs were compared between SET from poor cohort and DET group, the outcomes were better in DET group (22.1 % vs 53.7 %, p < 0.001 and 22.1 % vs 43.1 %, p < 0.001). The PR and LBRs of SET from good cohort were significantly better than those of DET (64.4 % vs 53.7 %, p < 0.001 and 57.7 % vs 43.1, p < 0.001). When the PR and LBRs of SET from good cohort and SET from poor cohort were compared, better results were obtained in SET from good cohort.

CONCLUSION

The addition of poor quality embryo even is of benefit to the LBR, in the setting of when there is only one good quality blastocyst available for the transfer.

The practice of intracytoplasmic sperm injection in Jordan: A clinical outcome study

Objective

The lack of appropriate guidelines and justified practice in most developing countries is a serious limitation to efforts to qualify the services provided. In this paper, we evaluate and assess the clinical practice of an assisted reproductive technique of intracytoplasmic sperm injection (ICSI) in Jordan.

Methods

Retrospectively, we identified women who achieved a successful pregnancy by ICSI over a period of ten years. Information related to the ICSI procedure, foetus abnormalities, maternal complications and delivery outcomes were included. A control group of normal pregnancies were incorporated.

Results

In total, 291 cases were included as successful cases of ICSI with a success rate of 14.1%. For the control group, 466 pregnant women with normal pregnancies were included. No statistical difference was observed between both groups in foetus malformation. In normal pregnancy women, 42.1% delivered through caesarean section (CS) while 87.6% of ICSI patients underwent CS. Women with ICSI had significantly higher rates of multiple gestations, and their neonates were lower in birthweight. Women in the ICSI group tended to deliver females compared to the control group. Pregnancy-related hypertension was more commonly reported in the normal pregnancy group, while gestational diabetes, antepartum haemorrhage and preterm labour were more common in ICSI group.

Conclusion

Services for the management of infertility are increasing in the Middle East. The clinical outcomes in Jordan is approaching that of other developed regions, although the success rate is lower than in other regions. Further studies and efforts should be carried out to maximize effective and successful practice in such low-income areas.

•

The practice of ICSI needs to be justified in the developing countries.

•

The success rate of ICSI is low with higher rates of CS and multiple gestation.

•

Neonates for women with ICSI are born with lower birth weight.

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

BACKGROUND

Transfer of more than one embryo during in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) increases multiple pregnancy rates resulting in an increased risk of maternal and perinatal morbidity. Elective single embryo transfer offers a means of minimising this risk, but this potential gain needs to be balanced against the possibility of jeopardising the overall live birth rate (LBR).

OBJECTIVES

To evaluate the effectiveness and safety of different policies for the number of embryos transferred in infertile couples undergoing assisted reproductive technology cycles.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group specialised register of controlled trials, CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform from inception to March 2020. We handsearched reference lists of articles and relevant conference proceedings. We also communicated with experts in the field regarding any additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing different policies for the number of embryos transferred following IVF or ICSI in infertile women. Studies of fresh or frozen and thawed transfer of one to four embryos at cleavage or blastocyst stage were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial eligibility and risk of bias. The primary outcomes were LBR and multiple pregnancy rate. The secondary outcomes were clinical pregnancy and miscarriage rates. We analysed data using risk ratios (RR), Peto odds ratio (Peto OR) and a fixed effect model.

MAIN RESULTS

We included 17 RCTs in the review (2505 women). The main limitation was inadequate reporting of study methods and moderate to high risk of performance bias due to lack of blinding. A majority of the studies had low numbers of participants. None of the trials compared repeated single embryo transfer (SET) with multiple embryo transfer. Reported results of multiple embryo transfer below refer to double embryo transfer. Repeated single embryo transfer versus multiple embryo transfer in a single cycle Repeated SET was compared with double embryo transfer (DET) in four studies of cleavage-stage transfer. In these studies the SET group received either two cycles of fresh SET (one study) or one cycle of fresh SET followed by one frozen SET (three studies). The cumulative live birth rate after repeated SET may be little or no different from the rate after one cycle of DET (RR 0.95, 95% CI (confidence interval) 0.82 to 1.10; I² = 0%; 4 studies, 985 participants; low-quality evidence). This suggests that for a woman with a 42% chance of live birth following a single cycle of DET, the repeated SET would yield pregnancy rates between 34% and 46%. The multiple pregnancy rate associated with repeated SET is probably reduced compared to a single cycle of DET (Peto OR 0.13, 95% CI 0.08 to 0.21; I² = 0%; 4 studies, 985 participants; moderate-quality evidence). This suggests that for a woman with a 13% risk of multiple pregnancy following a single cycle of DET, the risk following repeated SET would be between 0% and 3%. The clinical pregnancy rate (RR 0.99, 95% CI 0.87 to 1.12; I² = 47%; 3 studies, 943 participants; low-quality evidence) after repeated SET may be little or no different from the rate after one cycle of DET. There may be little or no difference in the miscarriage rate between the two groups. Single versus multiple embryo transfer in a single cycle A single cycle of SET was compared with a single cycle of DET in 13 studies, 11 comparing cleavage-stage transfers and three comparing blastocyst-stage transfers.One study reported both cleavage and blastocyst stage transfers. Low-quality evidence suggests that the live birth rate per woman may be reduced in women who have SET in comparison with those who have DET (RR 0.67, 95% CI 0.59 to 0.75; I² = 0%; 12 studies, 1904 participants; low-quality evidence). Thus, for a woman with a 46% chance of live birth following a single cycle of DET, the chance following a single cycle of SET would be between 27% and 35%. The multiple pregnancy rate per woman is probably lower in those who have SET than those who have DET (Peto OR 0.16, 95% CI 0.12 to 0.22; I² = 0%; 13 studies, 1952 participants; moderate-quality evidence). This suggests that for a woman with a 15% risk of multiple pregnancy following a single cycle of DET, the risk following a single cycle of SET would be between 2% and 4%. Low-quality evidence suggests that the clinical pregnancy rate may be lower in women who have SET than in those who have DET (RR 0.70, 95% CI 0.64 to 0.77; I² = 0%; 10 studies, 1860 participants; low-quality evidence). There may be little or no difference in the miscarriage rate between the two groups.

AUTHORS' CONCLUSIONS

Although DET achieves higher live birth and clinical pregnancy rates per fresh cycle, the evidence suggests that the difference in effectiveness may be substantially offset when elective SET is followed by a further transfer of a single embryo in fresh or frozen cycle, while simultaneously reducing multiple pregnancies, at least among women with a good prognosis. The quality of evidence was low to moderate primarily due to inadequate reporting of study methods and absence of masking those delivering, as well as receiving the interventions.

Impact of Transferring a Poor Quality Embryo Along with a Good Quality Embryo on Pregnancy Outcomes in IVF/ICSI Cycles: a Retrospective Study

Background The number and the quality of embryos transferred are important predictors of success in in vitro fertilization (IVF) cycles. In the presence of more than one good quality embryo on the transfer day, double-embryo transfer (DET) can be performed with these embryos, but generally, different quality embryos are present in the available transfer cohort. We aimed to investigate the effect of transferring a poor quality embryo along with a good quality embryo on IVF outcomes. Methods In this study, 2298 fresh IVF/intracytoplasmic sperm injection (ICSI) cycles with two good quality embryos (group A), one good and one poor quality embryo (group B), and single good quality embryo (group C) transfers were examined. All groups were divided into two subgroups according to the transfer day as cleavage or blastocyst stage. Clinical pregnancy and live birth rates were the primary outcomes. Results In the cleavage stage transfer subgroups, the clinical pregnancy rates were lower in the single-embryo transfer (SET) subgroup compared with DET subgroups, but the difference was not statistically significant compared with DET with mixed quality embryos. The live birth rates were comparable between the three groups. In the blastocyst transfer subgroups, the clinical pregnancy and live birth rates were significantly higher in DET with two good quality embryos than DET with mixed quality embryos and SET groups. Multiple pregnancy rates were higher in both DET groups in terms of transfer day (p = 0.001). Conclusion DET with mixed quality embryos results with lower clinical pregnancy and live birth rates compared with DET with two good quality embryos at the blastocyst stage. At cleavage stage transfer, there is no difference in live birth rates between the two groups.

The Association Between Embryo Quality, Number of Transferred Embryos and Live Birth Rate After Vitrified Cleavage-Stage Embryos and Blastocyst Transfer

Objective

The single-embryo transfer (SET) is the recommended approach to improve the live birth rate and reduce the complications related with multiple pregnancies. However, the physicians generally chose to transfer two embryos when the embryo quality decreased. The effect on the in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) outcomes following the transfer of a poor-quality embryo (PQE) along with a good-quality embryo (GQE) has been explored. However, previous studies were limited by the fresh embryo transfer cycles or the small sample size.

Methods

A retrospective cohort study was performed among 26,676 women (the mean age was 31.72 years) undergoing first frozen embryo transfer (FET) from January 2011 to December 2017. Patients were grouped into five subgroups, including SET with one GQE (SET-GQE, 2235 patients for cleavage-stage embryo transfer and 756 patients for blastocyst transfer), SET with one PQE (SET-PQE, 148 patients for cleavage-stage embryo transfer and 362 patients for blastocyst transfer), double-embryo transfer with two GQE (DET-2GQE, 20,461 patients for cleavage-stage embryo transfer and 519 patients for blastocyst transfer), double-embryo transfer (DET) with one GQE plus one PQE (DET-GQE+PQE, 1541 patients for cleavage-stage embryo transfer and 266 patients for blastocyst transfer), and DET with two PQE (DET-2PQE, 228 patients for cleavage-stage embryo transfer and 160 patients for blastocyst transfer). Multivariable logistic regression models were performed after controlling for other potential confounders to estimate the effect of number and quality of transferred embryos on pregnancy outcomes.

Result

Although the live birth rate was significantly higher after DET-GQE+PQE compared with SET-GQE for cleavage-stage embryo transfer [574 of 1541 (37.25%) vs. 571 of 2235 (25.55%)], no significant difference was found between DET-GQE+PQE and SET-GQE for blastocyst transfer [143 of 266 (53.76%) vs. 325 of 756 (42.99%)]. However, DET-GQE+PQE also had the highest multiple live births in both cleavage-stage embryo transfer [134 of 1541 (8.70%)] and blastocyst transfer [46 of 266 (17.29%)]. The live birth rate after SET-PQE significantly decreased in comparison with SET-GQE [cleavage-stage embryo transfer: 18 of 148 (12.16%) vs. 571 of 2235 (25.55%); blastocyst transfer: 107 of 362 (29.56%) vs. 325 of 756 (42.99%)] and significantly increased after DET-2GQE compared with SET-GQE [cleavage-stage embryo transfer: 9357 of 20,461 (45.73%) vs. 571 of 2235 (25.55%); blastocyst transfer: 313 of 519 (60.31%) vs. 325 of 756 (42.99%)]. The live birth rate was also not different between DET-2PQE and SET-GQE for cleavage-stage embryo transfer and blastocyst transfer [cleavage-stage embryo transfer: 75 of 228 (32.89%) vs. 571 of 2235 (25.55%); blastocyst transfer: 74 of 160 (46.25%) vs. 325 of 756 (42.99)].

Conclusion

In order to minimize the risk of multiple births, the data from this study did not support transferring DET with a GQE plus a PQE compared with SET with a GQE, especially for blastocyst transfer. However, the proportion of patients older than 35 years was small (12.07% for patients aged 36-39 years and 7.31% for patients 40 years or older), which limited the generalization of these results to other population.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Non-invasive mitochondrial DNA quantification on Day 3 predicts blastocyst development: a prospective, blinded, multi-centric study

In ART, embryo quality evaluation is routinely based on morphological criteria. We previously demonstrated that the mitochondrial DNA (mtDNA)/genomic DNA (gDNA) ratio in culture medium was significantly associated with embryo quality and viability potential. The purpose of this prospective, blinded, multi-centric study was to validate the use of mtDNA/gDNA ratio in Day 3 spent medium as a predictor of human embryo developmental competence. The mtDNA/gDNA ratio was assessed in Day 3 culture media (n=484) of embryos from 143 patients by quantitative PCR. A mixed effect logistic regression model was applied. We found that mtDNA/gDNA ratio in Day 3 culture medium combined with embryo morphology improves the prediction upon blastulation compared to morphology alone (P < 0.0001), independent of patient and cycle characteristics. With regard to routine use in clinics, we evaluated the ability of the novel, combined grading score to improve selection of developmentally competent embryos of a single cohort. Including embryos from 44 patients, the sensibility and specificity of the scoring system based on Day 3 morphological stage were 92% and 13%, respectively. Integration with the culture medium mtDNA/gDNA ratio increased the performance of the method (sensibility: 95%; specificity: 65%). The results of this study suggest the possibility of carrying out a non-invasive evaluation of embryonic mtDNA content through the culture medium. When combined with embryo morphology, it has the potential to help embryologists rank embryos and choose which embryo(s) has the greater development potential, and thus should be transferred on Day 3, among sibling embryos with the same morphological grade.

Preimplantation Genetic Testing: Where We Are Today

BACKGROUND

Preimplantation genetic testing (PGT) is widely used today in in-vitro fertilization (IVF) centers over the world for selecting euploid embryos for transfer and to improve clinical outcomes in terms of embryo implantation, clinical pregnancy, and live birth rates.

METHODS

We report the current knowledge concerning these procedures and the results from different clinical indications in which PGT is commonly applied.

RESULTS

This paper illustrates different molecular techniques used for this purpose and the clinical significance of the different oocyte and embryo stage (polar bodies, cleavage embryo, and blastocyst) at which it is possible to perform sampling biopsies for PGT. Finally, genetic origin and clinical significance of embryo mosaicism are illustrated.

CONCLUSIONS

The preimplantation genetic testing is a valid technique to evaluated embryo euploidy and mosaicism before transfer.

Precise Personalized Medicine in Gynecology Cancer and Infertility

Since the conception of precision medicine has been put forward in oncology, this idea has been popularized and applied in many specialties. Significant progress has been made toward personalizing the entire process, including diagnosis, treatment planning, and embryo identification, and combining large-scale genetic information data and knowledge discovery can offer better prospects in reproductive medicine. This work reviews the application of precision medicine and possibilities in reproductive medicine and gynecologic cancer diagnosis and treatment. The limitations and challenges of precision medicine in this area remain to be discussed.

Risk Factors of Recurrent Ectopic Pregnancy in Patients Treated With in vitro Fertilization Cycles: A Matched Case-Control Study

Objective: To study the risk factors for recurrent ectopic pregnancy (REP) in patients undergoing in vitro fertilization (IVF). Methods: This was a 1:4 matched case-control study that enrolled 227 REP patients and 908 matched intrauterine pregnancy (IUP) patients from the assisted reproductive technology (ART) center of the First Affiliated Hospital of Zhengzhou University from January 2012 to November 2019. Univariate analysis was carried out between the two groups for the occurrence of REP. Multivariate logistic regression analysis was used to explore the risk factors of REP after IVF. Results: The results of univariate analysis showed that there were significant differences in previous treatment of EP, stage of embryo and the number of embryos transferred between the two groups (all P < 0.05). The other factors did not have a significant effect on the probability of developing REP. Multivariate logistic regression analysis showed that after adjusting for confounders, previous treatment of EP, type of embryos transferred and stage of embryo were related to the occurrence of REP (all P < 0.05). Conclusion: Conservative treatment, frozen-thawed embryo transfer and cleavage embryo transfer were independent risk factors for REP after ART treatment.

Effect of transfer of a poor quality embryo along with a top quality embryo on the outcome during fresh and frozen in vitro fertilization cycles

OBJECTIVE

To evaluate the impact of a poor quality embryo (PQE) during double ET (DET) with a top quality embryo (TQE) on IVF outcome.

DESIGN

A review of prospectively collected data.

SETTING

Tertiary level fertility clinic.

PATIENT(S)

All patients undergoing blastocyst transfers as part of fresh IVF (n = 939) and frozen ET (n = 1,009) cycles performed between 2010 and 2016.

INTERVENTION(S)

Single ET (SET) with TQE (group 1) was set as control and compared with outcomes for SET with PQE (group 2), DET with 2 TQEs (group 3), PQE plus TQE (group 4), and 2 PQE (group 5).

MAIN OUTCOME MEASURE(S)

Live births and multiple births.

RESULT(S)

The live birth rates for group 4 were statistically similar to group 1 during fresh IVF (26.5% vs. 33.7%; odds ratio [OR], 0.95; 95% confidence interval [CI] 0.53-1.7) and frozen ET (24.2% vs. 32.7%; OR, 0.75; 95% CI 0.48-1.2), although there was a trend for lower success. Conversely, multiple births were higher in group 4 for fresh IVF (19% vs. 4.7%; OR, 2.9; 95% CI 1.3-6.6) and frozen ET (10.3% vs. 2.6%; OR, 2.4; 95% CI 1.2-4.9). The live birth rates for group 2 (12.2% for fresh IVF and 14.6% for frozen ET) and group 5 (21.2% for fresh IVF and 14% for frozen ET) were lower and for group 3 were higher (40.8% for fresh IVF and 40.3% for frozen ET) when compared with group 1. Multiple births were significantly higher with DET.

CONCLUSION(S)

This study does not support DET with one PQE along with a TQE, when there is only one TQE and one or more PQEs available for fresh IVF or frozen ET.

Frozen blastocyst transfer reduces incidence of ectopic pregnancy compared with fresh blastocyst transfer: a meta-analysis

BACKGROUND

Ectopic pregnancy (EP) is the main cause of maternal death during early pregnancy. Blastocyst transfer (BT) reduces EP rates compared with cleavage stage embryo transfer (ET), and frozen ET reduces EP rates compared with fresh ET. However, data comparing the EP rate of fresh BT and frozen BT are limited. The objective of this meta-analysis was to determine whether frozen BT decreases the EP rate compared with fresh BT.

MATERIALS AND METHODS

PUBMED, EMBASE, and Cochrane Library databases were searched for papers with no limitation on language and publication year. A systemic literature search identified 14 studies which met the inclusion criteria for further analysis. EP rate is our only outcome measure. All statistical analyses were carried out using RevMan software [version 5.3]. Random effects models were chosen to calculate the odds ratio (OR).

RESULTS

Fourteen retrospective studies (n = 251,762 cycles) were finally analyzed, including 154,214 and 97,548 cycles undergoing fresh and frozen BT, respectively. Compared with fresh BT, the frozen BT was associated with an decrease in EP rate [OR = 1.79; 95% confidence interval (CI) = 1.37-2.34, heterogeneity was 71%], the EP rate was 1.74% (2683/154,214 pregnancies) for fresh BT and 0.97% (949/97,548 pregnancies) for frozen BT. The number of embryos transferred in subgroup analysis found that the incidence of EP in frozen BT is lower than fresh BT (OR = 1.62; 95% CI = 1.38-1.91), the EP rate was 1.2% (206/16,610 pregnancies) for one fresh BT and 0.8% (153/19,569 pregnancies) for one frozen BT, also the EP rate was 1.9% (78/4043 pregnancies) for two fresh BT and 1.1% (19/1790 pregnancies) for two frozen BT.

CONCLUSIONS

Our meta-analysis found that frozen BT was associated with an decrease in EP rate compared with fresh BT in IVF/ICSI patients. We also found that a single frozen BT is the better choice as a method to reduce the incidence of EP.

Does a poor-quality embryo have an adverse impact on a good-quality embryo when transferred together?

BACKGROUND

In some in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles, we may consider transferring one poor-quality embryo with one good-quality embryo. Previous studies have indicated that the poor-quality embryo transferred with a good-quality embryo does not negatively affect the clinical pregnancy rate or live birth rate. The purpose of this study was to evaluate pregnancy outcomes and neonatal outcomes in this context.

METHODS

This was a retrospective study that included 1646 cycles from our centre. Patients were divided into two groups (group A: one good-quality embryo was transferred with one poor-quality embryo; group B: two good-quality embryos were transferred). The primary outcomes were the clinical pregnancy rate and live birth rate. Additionally, we investigated the implantation rate, ectopic pregnancy rate, abortion rate, multiple pregnancy rate, birthweight and gestational age.

RESULTS

We found that there were no differences in the clinical pregnancy rate and live birth rate between group A and group B. However, the implantation rate and multiple pregnancy rate were higher in group B than in group A.

CONCLUSIONS

The poor-quality embryo does not have a significant influence on the good-quality embryo when transferred together.

Making IVF more effective through the evolution of prediction models: is prognosis the missing piece of the puzzle?

Assisted reproductive technology has evolved tremendously since the emergence of in vitro fertilization (IVF). In the course of the recent decade, there have been significant efforts in order to minimize multiple gestations, while improving percentages of singleton pregnancies and offering individualized services in IVF, in line with the trend of personalized medicine. Patients as well as clinicians and the entire IVF team benefit majorly from 'knowing what to expect' from an IVF cycle. Hereby, the question that has emerged is to what extent prognosis could facilitate toward the achievement of the above goal. In the current review, we present prediction models based on patients' characteristics and IVF data, as well as models based on embryo morphology and biomarkers during culture shaping a complication free and cost-effective personalized treatment. The starting point for the implementation of prediction models was initiated by the aspiration of moving toward optimal practice. Thus, prediction models could serve as useful tools that could safely set the expectations involved during this journey guiding and making IVF treatment more effective. The aim and scope of this review is to thoroughly present the evolution and contribution of prediction models toward an efficient IVF treatment.

ABBREVIATIONS

IVF: In vitro fertilization; ART: assisted reproduction techniques; BMI: body mass index; OHSS: ovarian hyperstimulation syndrome; eSET: elective single embryo transfer; ESHRE: European Society of Human Reproduction and Embryology; mtDNA: mitochondrial DNA; nDNA: nuclear DNA; ICSI: intracytoplasmic sperm injection; MBR: multiple birth rates; LBR: live birth rates; SART: Society for Assisted Reproductive Technology Clinic Outcome Reporting System; AFC: antral follicle count; GnRH: gonadotrophin releasing hormone; FSH: follicle stimulating hormone; LH: luteinizing hormone; AMH: anti-Müllerian hormone; DHEA: dehydroepiandrosterone; PCOS: polycystic ovarian syndrome; NPCOS: non-polycystic ovarian syndrome; CE: cost-effectiveness; CC: clomiphene citrate; ORT: ovarian reserve test; EU: embryo-uterus; DET: double embryo transfer; CES: Cumulative Embryo Score; GES: Graduated Embryo Score; CSS: Combined Scoring System; MSEQ: Mean Score of Embryo Quality; IMC: integrated morphology cleavage; EFNB2: ephrin-B2; CAMK1D: calcium/calmodulin-dependent protein kinase 1D; GSTA4: glutathione S-transferase alpha 4; GSR: glutathione reductase; PGR: progesterone receptor; AMHR2: anti-Müllerian hormone receptor 2; LIF: leukemia inhibitory factor; sHLA-G: soluble human leukocyte antigen G.

Mixed double-embryo transfer: A promising approach for patients with repeated implantation failure

Objective

The purpose of this study was to evaluate the efficacy of frozen mixed double-embryo transfer (MDET; the simultaneous transfer of day 3 and day 5 embryos) in comparison with frozen blastocyst double-embryo transfer (BDET; transfer of two day 5 blastocysts) in patients with repeated implantation failure (RIF).

Methods

A total of 104 women with RIF who underwent frozen MDET (n=48) or BDET (n=56) with excellent-quality embryos were included in this retrospective analysis. All frozen embryo transfers were performed in natural cycles. The main outcome measures were the implantation rate, clinical pregnancy rate, multiple pregnancy rate, and miscarriage rate. These measures were compared between the patients who underwent MDET or BDET using the chi-square test or the Fisher exact test, as appropriate.

Results

The implantation and clinical pregnancy rates were significantly higher in patients who underwent MDET than in those who underwent BDET (60.4% vs. 39.3%, p=0.03 and 52.1% vs. 30.4%, p=0.05, respectively). A significantly lower miscarriage rate was observed in the MDET group (6.9% vs. 10.7%, p=0.05). In addition, the multiple pregnancy rate was slightly, but not significantly, higher in the MDET group (27.1% vs. 25.0%).

Conclusion

MDET was found to be significantly superior to double blastocyst transfer. It could be regarded as an appropriate approach to improve in vitro fertilization success rates in RIF patients.

Pregnancy rates for single embryo transfer (SET) of day 5 and day 6 blastocysts after cryopreservation by vitrification and slow freeze

PURPOSE

The purpose of this study was to compare clinical and ongoing pregnancy rates in cycles with single embryo transfer (SET) of blastocysts cryopreserved on day 5 or day 6. Our aim was to determine whether day 6 blastocysts perform adequately to recommend SET.

METHODS

Retrospective cohort study including 468 transfer cycles for 392 women younger than age 38 undergoing SET at a university-affiliated IVF clinic in the USA. A total of 261 day 5 blastocysts and 207 day 6 blastocysts for frozen-thawed SET between 2010 and 2016 were analyzed. Data included cryopreservation by both a slow freeze method and vitrification.

RESULTS

In total, 59.0% of day 5 SET cycles resulted in a clinical pregnancy compared to 54.1% of day 6 blastocysts (p = 0.54). Ongoing pregnancy rates from day 5 frozen-thawed blastocysts (51.7%) were comparable to day 6 (44.9%, p = 0.14). When looking at vitrified blastocysts only, there were no significant differences between day 5 and day 6 blastocysts, with a clinical pregnancy rate of 69.2% for day 5 and 72.5% for day 6 (p = 0.68).

CONCLUSIONS

SETs of day 6 cryopreserved blastocysts resulted in similar clinical and ongoing pregnancy rates compared to day 5, particularly after vitrification.

Systematic review of worldwide trends in assisted reproductive technology 2004-2013

BACKGROUND

Assisted Reproductive Technology (ART) has undergone considerable changes over the last decade, with consequences on ART outcomes in different regions of the world being unknown.

METHODS

We conducted a systematic review of published national and regional ART registry data to assess how changes in clinical practice between 2004 and 2013 have impacted outcomes in Australia and New Zealand, Canada, Continental Europe, the United Kingdom (U.K.), Japan, Latin America, and the United States (U.S.). The data reflect 7,079,145 total ART cycles utilizing both fresh and previously cryopreserved embryos from autologous oocytes that resulted in 1,454,724 live births. This review focused on the following measures: ART cycle volume, use of cryopreserved embryos, single embryo transfer (SET), live birth rates in fresh and frozen-thawed cycles, and perinatal outcomes in recent years.

RESULTS

SETs and utilization of frozen-thawed embryos increased worldwide over the study period. In 2012 SET utilization in all ART cycles was highest in Japan and Australia/New Zealand (82.6% and 76.3% respectively) and lowest in Latin America (16.0%). While gradual improvements in live birth rates were observed in most regions, some demonstrated declines. By 2012-2013, fresh cycle live birth rates were highest in the U.S. (29%) and lowest in Japan (5%). In Japan, the observed decline in fresh cycle live birth rate coincided with transition to minimal stimulation protocols, transfer of frozen-thawed rather than fresh embryos, and implementation of an SET policy. Similarly, implementation of an SET policy in parts of Canada was followed by a decline in fresh cycle live birth rate. Increasing live birth rates in frozen-thawed embryo cycles, seen all over the world, partially compensated for declines in fresh ART cycles. During 2012-2013 Australia/New Zealand and Japan reported the lowest multiple delivery rates of 5.6 and 4% respectively while the US had the highest of 27%. In recent years, preterm delivery rates in all regions ranged between 9.0 to 16.6% for singletons, 53.9 to 67.3% for twins, and 91.4 to 100% for triplets and higher order multiples. Inconsistencies in the way perinatal outcome data are presented by various registries, made comparison between regions difficult.

CONCLUSIONS

ART practices are characterized by outcome differences between regions. International consensus on the definition of ART success, which accounts for perinatal outcomes, may help to standardize worldwide ART practice and improve outcomes.

TRIAL REGISTRATION

PROSPERO ( CRD42016033011 ).

Is elective single-embryo transfer a viable treatment policy in in vitro maturation cycles?

OBJECTIVE

To compare the clinical outcome of single-embryo transfer (SET) with double-embryo transfer (DET) in in vitro maturation (IVM) cycles performed in patients with polycystic ovary syndrome (PCOS), and to determine which factors predict those outcomes.

DESIGN

A retrospective analysis.

SETTING

Private assisted reproduction center.

PATIENT(S)

One hundred and fifty-nine women with PCOS.

INTERVENTION(S)

In vitro maturation with elective SET or DET conducted between September 2007 and May 2014.

MAIN OUTCOME MEASURE(S)

Live-birth rates.

RESULT(S)

Single-embryo transfer was performed in 83 patients (52.2%), and DET was performed in 76 patients (47.7%). When compared with the patients who had DET, the patients who had SET were statistically significantly younger (32.4 ± 3.5 vs. 24.1 ± 4.2 years) and had a shorter infertility duration (9.2 ± 4.5 vs. 4.4 ± 2.1 years), fewer previous ART cycles (<2 prior attempts, 39.5% vs. 6%; ≥2 prior attempts, 60.5% vs. 0), fewer collected oocytes (15.1 ± 4.6 vs. 12.6 ± 3.8), fewer metaphase II oocytes (9.0 ± 4.1 vs. 5.7 ± 2.9), fewer fertilized oocytes (8.2 ± 3.7 vs. 3.6 ± 2.3), and a higher implantation rate (27% vs. 47%). The SET and DET groups had similar embryo quality and similar clinical pregnancy (44.6% vs. 44.7%) and live-birth rates (34.9% vs. 34.2%). Twin pregnancy rates were statistically significantly higher in the DET compared with the SET groups (9.2% vs. 2.4%).

CONCLUSION(S)

In vitro maturation is a successful assisted reproduction technique that can be an alternative to conventional in vitro fertilization in women presenting with PCOS-related infertility. Our observations suggest that SET is a feasible option to prevent multiple pregnancies while maintaining the live-birth rate.

[Pregnancy and obstetric outcomes of elective single versus double cleavage-stage embryo transfer]

OBJECTIVE

To compare the pregnancy and obstetric outcomes in elective single versus two cleavage-stage embryo transfer.

METHODS

Fresh cleavage-stage embryo transfer cycles between January, 2014 and October, 2015 were reviewed, including 39 single embryo transfer (eSET) cycles and 200 double embryo transfer (DET) cycles. The clinical pregnancy rates, implantation rates, multiple pregnancy rates, live birth rate, and obstetric outcomes (gestational age, preterm delivery rate and mean birth weight) were compared between the two groups.

RESULTS

The baseline characteristics were comparable between the two groups. The estradiol level on the day of trigger and the oocyte number were significantly higher in eSET group than in DET group (10654.4 pmol/L vs 8284.2 pmol/L and 8.4 vs 7.0, respectively). No significant difference was found in the pregnancy rate (56.4% vs 66.0%) or live birth rate (48.7% vs 51.5%) between the two groups, and their implantation rates differed significantly (56.4% vs 37.8%). No multiple pregnancies occurred in eSET group while the rate of multiple pregnancies was 22.7% in DET group. The gestational age and mean birth weight were significantly higher in eSET group (P<0.05), and the preterm delivery rate after DET was nearly three times of that after eSET, although this difference was not statistically significant.

CONCLUSIONS

Elective single embryo transfer can be performed without compromising the live birth rates. Multiple pregnancy rates can be significantly reduced with eSET, which also results in a higher chance of delivering a term singleton live birth compared with DET.

Risk of ectopic pregnancy lowest with transfer of single frozen blastocyst

STUDY QUESTION

What type of transferred embryo is associated with a lower rate of ectopic pregnancy?

SUMMARY ANSWER

The lowest risk of ectopic pregnancy was associated with the transfer of blastocyst, frozen and single embryo compared with cleavage stage, fresh and multiple embryos.

WHAT IS KNOWN ALREADY

Ectopic pregnancy is a recognized complication following assisted reproductive technology (ART) treatment. It has been estimated that the rate of ectopic pregnancy is doubled in pregnancies following ART treatment compared with spontaneous pregnancies. However, it was not clear whether the excess rate of ectopic pregnancy following ART treatment is related to the underlying demographic factors of women undergoing ART treatment, the number of embryos transferred or the developmental stage of the embryo.

STUDY DESIGN, SIZE, DURATION

A population-based cohort study of pregnancies following autologous treatment cycles between January 2009 and December 2011 were obtained from the Australian and New Zealand Assisted Reproduction Technology Database (ANZARD). The ANZARD collects ART treatment information and clinical outcomes annually from all fertility centres in Australia and New Zealand.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Between 2009 and 2011, a total of 44 102 pregnancies were included in the analysis. The rate of ectopic pregnancy was compared by demographic and ART treatment factors. Generalized linear regression of Poisson distribution was used to estimate the likelihood of ectopic pregnancy. Odds ratios, adjusted odds ratios (AOR) and 95% confidence intervals (CI) were calculated.

MAIN RESULTS AND THE ROLE OF CHANCE

The overall rate of ectopic pregnancy was 1.4% for women following ART treatment in Australia and New Zealand. Pregnancies following single embryo transfers had 1.2% ectopic pregnancies, significantly lower than double embryo transfers (1.8%) (P < 0.01). The highest ectopic pregnancy rate was 1.9% for pregnancies from transfers of fresh cleavage embryo, followed by transfers of frozen cleavage embryo (1.7%), transfers of fresh blastocyst (1.3%), and transfers of frozen blastocyst (0.8%). Compared with fresh blastocyst transfer, the likelihood of ectopic pregnancy was 30% higher for fresh cleavage stage embryo transfers (AOR 1.30, 95% CI 1.07-1.59) and was consistent across subfertility groups. Transfer of frozen blastocyst was associated with a significantly decreased risk of ectopic pregnancy (AOR 0.70, 95% CI 0.54-0.91) compared with transfer of fresh blastocyst.

LIMITATIONS, REASON FOR CAUTION

A limitation of this population-based study is the lack of information available on clinical- specific protocols and processes for embryo transfer (i.e. embryo quality, cryopreservation protocol, transfer techniques, etc.) and the potential impact on outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

The lowest risk of ectopic pregnancy was associated with the transfer of a single frozen blastocyst. This finding adds to the increasing evidence of better perinatal outcomes following frozen embryo transfers. The approach of freezing all embryos in the initiated fresh cycle and transfer of a single frozen blastocyst in the subsequent thaw cycle may improve the overall pregnancy and birth outcomes following ART treatment, in part by reducing the ectopic pregnancy rate.

STUDY FUNDING/COMPETING INTERESTS

There is no funding for this study. Authors declared no competing interest related to this study.

Application of a validated prediction model for in vitro fertilization: comparison of live birth rates and multiple birth rates with 1 embryo transferred over 2 cycles vs 2 embryos in 1 cycle

OBJECTIVE

The purpose of this study was to use a validated prediction model to examine whether single embryo transfer (SET) over 2 cycles results in live birth rates (LBR) comparable with 2 embryos transferred (DET) in 1 cycle and reduces the probability of a multiple birth (ie, multiple birth rate [MBR]).

STUDY DESIGN

Prediction models of LBR and MBR for a woman considering assisted reproductive technology developed from linked cycles from the Society for Assisted Reproductive Technology Clinic Outcome Reporting System for 2006-2012 were used to compare SET over 2 cycles with DET in 1 cycle. The prediction model was based on a woman's age, body mass index (BMI), gravidity, previous full-term births, infertility diagnoses, embryo state, number of embryos transferred, and number of cycles.

RESULTS

To demonstrate the effect of the number of embryos transferred (1 or 2), the LBRs and MBRs were estimated for women with a single infertility diagnosis (male factor, ovulation disorders, diminished ovarian reserve, and unexplained); nulligravid; BMI of 20, 25, 30, and 35 kg/m2; and ages 25, 35, and 40 years old by cycle (first or second). The cumulative LBR over 2 cycles with SET was similar to or better than the LBR with DET in a single cycle (for example, for women with the diagnosis of ovulation disorders: 35 years old; BMI, 30 kg/m2; 54.4% vs 46.5%; and for women who are 40 years old: BMI, 30 kg/m(2); 31.3% vs 28.9%). The MBR with DET in 1 cycle was 32.8% for women 35 years old and 20.9% for women 40 years old; with SET, the cumulative MBR was 2.7% and 1.6%, respectively.

CONCLUSION

The application of this validated predictive model demonstrated that the cumulative LBR is as good as or better with SET over 2 cycles than with DET in 1 cycle, while greatly reducing the probability of a multiple birth.

Debating Elective Single Embryo Transfer after in vitro Fertilization: A Plea for a Context-Sensitive Approach

The number of embryos transferred after in vitro fertilization (IVF) have been a topic of debate for over a decade now. Due to the risk associated with multiple pregnancy, there has been a global effort at reducing the multiple pregnancy rates to a minimum while maintaining an acceptable level of successful IVF pregnancy rate. Elective single embryo transfer (eSET) is advocated in most European countries. In Belgium and Sweden, eSET is mandatory for couples with a good prognosis. However, despite clinical recommendations and policy statements, patients in clinical practice frequently do request for the transfer of multiple embryos in order to have twins. Such requests conflict with policy guidelines and create an ethical dilemma for physicians: Should the physician do as the couple requests, and there with respect the autonomy of patients, or adhere to medical policy that takes the health of the mother and children at heart? This article provides an exploration of the arguments found in the literature that plays a role in the discussion on this topic and eventually argues that what a physician should do depends on the specificities of the context in which patients and physicians are implicated. These contextual issues can be taken into account in a shared decision-making procedure, which allows reflections and the responsibilities of both patients and physicians to be attended in decision about assisted reproduction.

Perinatal outcome after fetal reduction from twin to singleton: to reduce or not to reduce?

OBJECTIVE

To determine whether reduction of twin gestation to singleton pregnancy is associated with improved perinatal outcome.

DESIGN

A retrospective cohort study.

SETTING

Single tertiary care medical center.

PATIENT(S)

A cohort of 63 singleton pregnancies after reduction from dichorionic-diamniotic twins gestation and 62 dichorionic-diamniotic nonreduced twins.

INTERVENTION(S)

Fetal reduction between 11 and 14 weeks of gestation.

MAIN OUTCOME MEASURE(S)

Obstetric outcome.

RESULT(S)

The rates of preterm delivery at <34 weeks (1.6% in pregnancies after reduction vs. 11.7% in nonreduced twins) and at <37 weeks of gestation (9.5% vs. 56.7%) were significantly lower in patients whose pregnancies were reduced to singletons. The rates of miscarriage of one twin (0% vs. 4.8%) and early pregnancy loss before 24 weeks of gestation as well as the rates of gestational diabetes (11.1% vs. 10%), hypertensive diseases of pregnancy (6.3% vs. 15%), and intrauterine growth restriction (0% vs. 3.3%) were similar in both groups.

CONCLUSION(S)

Fetal reduction of twins to singleton is associated with a lower risk of prematurity and superior perinatal outcome compared with nonreduced twins. Therefore, the option of fetal reduction should be considered in certain cases of twin pregnancies, where the risk for adverse outcome seems exceptionally high.

Assisted reproductive technologies (ARTs): evaluation of evidence to support public policy development

Over the years, IVF/ICSI protocols have continued to evolve with efforts to improve outcomes. As a result, treatment success may be related to certain procedural factors, including number of embryos transferred and stage at which they are transferred. This review aims to assess the safety and effectiveness of IVF/ICSI in comparison to spontaneous conception and less invasive ARTs and the impact of procedure-related factors on the outcomes of IVF/ICSI in order to support the development of local clinical and policy guidance. Following Cochrane Collaboration guidelines and the PRISMA statement, a comprehensive systematic review of literature examining the impact of procedural characteristics on the safety or effectiveness of IVF/ICSI from 2007 to date was performed. 33 systematic reviews and 3 primary studies evaluating the impact of procedural differences, IVF/ICSI in comparison to less invasive ARTs, and ARTs in comparison to spontaneous conception were found. IVF was shown to offer significant benefits over no treatment and IUI in achieving pregnancy and live birth among couples with endometriosis or unexplained infertility. Frozen and blastocyst-stage embryo transfers were as effective as fresh and cleavage-stage embryo transfers, respectively. In comparison to single embryo transfer, double embryo transfer significantly increased pregnancy, live birth and multiple pregnancy/birth rates. IVF/ICSI was associated with more complications during pregnancy and delivery, and in infants compared to naturally conceived pregnancies, particularly when multiple embryo transfer was used. Frozen embryo transfer had fewer adverse events during pregnancy and delivery than fresh embryo transfer, and was at least as safe in terms of infant outcomes. The potential complications of IVF/ICSI may be minimized through procedural choices, but such choices often impact effectiveness. Thus, in developing clinical and policy guidance around IVF/ICSI, the risk-benefit trade-offs patients and providers are willing to accept must be carefully considered.

Clinical predictive criteria associated with live birth following elective single embryo transfer

OBJECTIVE

We aimed to define clinical criteria from the patients related to the occurrence of live birth in case of elective single embryo transfer (eSET).

STUDY DESIGN

We analyzed retrospectively 409 eSET at day 2/3 between March 2005 and July 2012, proposed in case of (i) woman's age <37 years, (ii) first/second IVF0 cycle, (iii) ≥2 good quality embryos obtained (3-5/6-10 blastomeres at day 2/3 and <20% fragmentation), including one top embryo (4/8 cells). In all, 124/409 live births (30.3%) were obtained, separating patients into groups of women who had birth or not. Different clinical parameters of interest were compared between each group, using appropriate statistical tests at p<0.05 significance level.

RESULTS

By comparing Body Mass Index (BMI), we report a statistically higher BMI among women who did not deliver (24.6 vs. 23.4kg/m(2); p=0.014). Using an analysis by BMI categories, we also precise a threshold of BMI≥30kg/m(2), negatively associated with the occurrence of live birth.

CONCLUSION

BMI appears to be the only clinical parameter statistically associated with delivery following eSET strategy in a good prognosis infertile population.

Embryonic aneuploidy: overcoming molecular genetics challenges improves outcomes and changes practice patterns

Since its inception, in vitro fertilization (IVF) has pursued molecular technology to improve patient outcomes, leading to enhanced methods of embryo selection. Comprehensive chromosomal screening (CCS) is a powerful tool that decreases maternal and neonatal morbidity due to multiple gestations by allowing the transfer of fewer embryos while maintaining success rates. To optimize this genetic test, physiological principles limiting the timing and type of cells to be removed had to be realized. Molecular barriers involved in genome amplification and ensuring the accuracy and validity of the CCS platform required a multistep approach to ensure that this technology was not used prematurely. Only after ensuring that the potential for harm was minimized and benefit maximized could clinicians use this technology to improve patient care.

Multiple pregnancies following assisted reproductive technologies--a happy consequence or double trouble?

The association between assisted reproduction technologies (ART) and multiple pregnancy is well-established, with a multiple birth rate of 24% in ART pregnancies. Multiple pregnancy is associated with significantly increased maternal and perinatal morbidity and mortality, as well as increased costs to the National Health Service. Evidence relating to the obstetric outcomes of ART twins versus naturally conceived twins is discussed in this review. Methods to reduce the risk of multiple births including elective single embryo transfer and multifetal pregnancy reduction are also discussed.

The impact of the embryo quality on the risk of multiple pregnancies

The aim of the present study was to determine the chance of pregnancy and the risk of multiple pregnancies taking into account the number and quality of transferred embryos in patients >36 years old or ≤36 years old. For this study, 1497 patients undergoing intra-cytoplasmic sperm injection (ICSI) cycles in a private assisted reproduction centre were split into groups according to the number and quality of the transferred embryos on the third or fifth day of development. The pregnancy rate and multiple pregnancy rate were compared between the embryo quality groups in patients <36 years old or ≥36 years old. In patients <36 years old, for the day 3 embryo transfer, no significant difference was noted in the pregnancy rate when the groups were compared. However the multiple pregnancy rate was increased by the transfer of an extra low-quality embryo (17.1 versus 28.2%, P = 0.020). For day 5 embryo transfer, the transfer of an extra blastocyst significantly increased the pregnancy rate (36.0 versus 42.4%, P < 0.001) and the multiple pregnancy rate (4.4 versus 16.9%, P < 0.001). In older patients, no significant difference was noted in the pregnancy rate when the groups were compared. However, when an extra low-quality embryo was transferred, a significantly increased rate of multiple pregnancies was observed for day 3 (18.2 versus 26.4%, P = 0.049) and day 5 embryo transfers (5.2 versus 16.1%, P < 0.001). In conclusion, the transfer of an extra low-quality embryo may increase the risk of a multiple pregnancy. In younger patients, the transfer of an extra low-quality blastocyst may also increase the chance of pregnancy.

Successful haematopoietic stem cell transplantation in 44 children from healthy siblings conceived after preimplantation HLA matching

Haematopoietic stem cell transplantation (HSCT) remains the best therapeutic option for many acquired and inherited paediatric haematological disorders. Unfortunately, the probability of finding an HLA matched donor is limited. An alternative technique is PGD combined with HLA matching, which offers the possibility of selecting unaffected embryos that are HLA compatible with the sick child, with the aim of possible use of stem cells from the resulting baby in future. Since the first successful report for Fanconi anaemia a decade ago, the therapeutic success of this technique was reported in a few cases and for a limited number of disorders. Here, we report full recovery of 44 sick children who received HSCT from healthy infants conceived after pre-implantation HLA matching for the following 10 indications; beta-thalassaemia, Wiskott-Aldrich syndrome, Fanconi anaemia, sickle cell anaemia, acute myeloid leukaemia, acute lymphoblastic leukaemia, Glanzmann's thrombasthaenia, Diamond-Blackfan anaemia, X-linked adrenoleukodystrophy and mucopolysaccharidosis type I. No serious complications were observed among recipients and donors. Graft failure occurred in four children with beta-thalassaemia where a second HSCT was planned. Preimplantation HLA matching is a reliable technique and provides a realistic option for couples seeking treatment for an affected child when no HLA-matched donor is available.

Obstetrical and neonatal outcomes from the BEST Trial: single embryo transfer with aneuploidy screening improves outcomes after in vitro fertilization without compromising delivery rates

OBJECTIVE

We sought to determine whether performing elective single embryo transfer (eSET) after trophectoderm biopsy and rapid aneuploidy screening results in improved obstetrical and neonatal outcomes compared with transferring 2 untested embryos.

STUDY DESIGN

The Blastocyst Euploid Selective Transfer (BEST) Trial enrolled infertile couples with a female partner up to age 42 years who were undergoing in vitro fertilization. They were randomized to receive transfer of a single euploid embryo (eSET) or to the standard of care with transfer of 2 embryos that were not biopsied for aneuploidy screening (untested 2-embryo transfer). Gestational age at delivery, birthweight, and neonatal intensive care unit (NICU) lengths of stay were compared with Mann-Whitney U. The risk of preterm delivery, low birthweight, and NICU admission were compared with χ(2).

RESULTS

Among the 175 randomized patients, the delivery rates were similar (69% after euploid eSET vs 72% after untested 2-embryo transfer; P = .6) through the fresh cycle and up to 1 frozen transfer, with a dramatic difference in multiple births (1.6% vs 47%; P < .0001). The risk of preterm delivery (P = .03), low birthweight (P = .002), and NICU admission (P = .04) were significantly higher after untested 2-embryo transfer. Babies born after untested 2-embryo transfer spent >5 times as many days in the NICU (479 vs 93 days; P = .03).

CONCLUSION

By enhancing embryo selection with a validated method of aneuploidy screening, a single euploid embryo with high reproductive potential can be selected for transfer. Using this approach, eSET can be performed without compromising delivery rates and improving the chance of having a healthy, term singleton delivery after in vitro fertilization.

A randomized controlled trial comparing two vitrification methods versus slow-freezing for cryopreservation of human cleavage stage embryos

Purpose

To compare two different vitrification methods to slow freezing method for cryopreservation of human cleavage stage embryos. Design: Prospective randomised trial. Setting: University assisted reproduction centre. Patient(s): 568 patients (mean age 33.4 ± 5.2) from April 2009 to April 2011.

Methods

1798 supernumerary good-quality cleavage stage embryos in 645 IVF cycles intended to be cryopreserved were randomly allocated to three groups: slow freezing, vitrification with the Irvine® method, vitrification with the Vitrolife® method. Main Outcome Measure(s): Embryo survival and cleavage rates, implantation rate.

Results

A total of 1055 embryos were warmed, 836 (79.2 %) survived and 676 were finally transferred (64.1 %). Post-warming embryos survival rate was significantly higher after vitrification (Irvine: 89.4 %; Vitrolife: 87.6 %) than after slow freezing (63.8 %) (p < 0.001). No differences in survival rates were observed between the two vitrification methods, but a significant higher cleavage rate was observed using Irvine compared to Vitrolife method (p < 0.05). Implantation rate (IR) per embryo replaced and per embryo warmed were respectively 15.8 % (41/259) and 12.4 % (41/330) for Irvine, 17.0 % (40/235) and 12.1 % (40/330) for Vitrolife, 21.4 % (39/182) and 9.9 % (39/395) for slow-freezing (NS).

Conclusions

Both vitrification methods (Irvine and Vitrolife) are more efficient than slow freezing for cryopreservation of human cleavage stage embryos in terms of post-warming survival rate. No significant difference in the implantation rate was observed between the three cryopreservation methods.

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

BACKGROUND

Multiple embryo transfer during in vitro fertilisation (IVF) increases multiple pregnancy rates causing maternal and perinatal morbidity. Single embryo transfer is now being seriously considered as a means of minimising the risk of multiple pregnancy. However, this needs to be balanced against the risk of jeopardising the overall live birth rate.

OBJECTIVES

To evaluate the effectiveness and safety of different policies for the number of embryos transferred in couples who undergo assisted reproductive technology (ART).

SEARCH METHODS

We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE, from inception to July 2013. We handsearched reference lists of articles, trial registers and relevant conference proceedings and contacted researchers in the field.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing different policies for the number of embryos transferred following IVF or intra-cytoplasmic sperm injection (ICSI) in subfertile women. Studies of fresh or frozen and thawed transfer of one, two, three or four embryos at cleavage or blastocyst stage were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and risk of bias and extracted the data. The overall quality of the evidence was graded in a summary of findings table.

MAIN RESULTS

Fourteen RCTs were included in the review (2165 women). Thirteen compared cleavage-stage transfers (2017 women) and two compared blastocyst transfers (148 women): one study compared both. No studies compared repeated multiple versus repeated single embryo transfer (SET). DET versus repeated SETDET was compared with repeated SET in three studies of cleavage-stage transfer. In these studies the SET group received either two cycles of fresh SET (one study) or one cycle of fresh SET followed by one frozen SET in a natural or hormone-stimulated cycle (two studies). When these three studies were pooled, the cumulative live birth rate after one cycle of DET was not significantly different from the rate after repeated SET (OR 1.22, 95% CI 0.92 to 1.62, three studies, n=811, I(2)=0%, low quality evidence). This suggests that for a woman with a 40% chance of live birth following a single cycle of DET, the chance following repeated SET would be between 30% and 42%. The multiple pregnancy rate was significantly higher in the DET group (OR 30.54, 95% CI 7.46 to 124.95, three RCTs, n = 811, I(2) = 23%, low quality evidence), suggesting that for a woman with a 15% risk of multiple pregnancy following a single cycle of DET, the risk following repeated SET would be between 0% and 2%. Single-cycle DET versus single-cycle SETA single cycle of DET was compared with a single cycle of SET in 10 studies, nine comparing cleavage-stage transfers and two comparing blastocyst-stage transfers. When all studies were pooled the live birth rate was significantly higher in the DET group (OR 2.07, 95% CI 1.68 to 2.57, nine studies, n = 1564, I(2) = 0%, high quality evidence). This suggests that for a woman with a 40% chance of live birth following a single cycle of DET, the chance following a single cycle of SET would be between 22% and 30%. The multiple pregnancy rate was also significantly higher in the DET group (OR 8.47, 95% CI 4.97 to 14.43, 10 studies, n = 1612, I(2) = 45%, high quality evidence), suggesting that for a woman with a 15% risk of multiple pregnancy following a single cycle of DET, the risk following a single cycle of SET would be between 1% and 4%. The heterogeneity for this analysis was attributable to a study with a high rate of cross-over between treatment arms. Other comparisons Other fresh cycle comparisons were evaluated in three studies which compared DET versus transfer of three or four embryos. Live birth rates did not differ significantly between the groups for any comparison, but there was a significantly lower multiple pregnancy rate in the DET group than in the three embryo transfer (TET) group (OR 0.36, 95% CI 0.13 to 0.99, two studies, n = 343, I(2) = 0%).

AUTHORS' CONCLUSIONS

In a single fresh IVF cycle, single embryo transfer is associated with a lower live birth rate than double embryo transfer. However, there is no evidence of a significant difference in the cumulative live birth rate when a single cycle of double embryo transfer is compared with repeated SET (either two cycles of fresh SET or one cycle of fresh SET followed by one frozen SET in a natural or hormone-stimulated cycle). Single embryo transfer is associated with much lower rates of multiple pregnancy than other embryo transfer policies. A policy of repeated SET may minimise the risk of multiple pregnancy in couples undergoing ART without substantially reducing the likelihood of achieving a live birth. Most of the evidence currently available concerns younger women with a good prognosis.

IVF and breast cancer: a systematic review and meta-analysis

BACKGROUND

The effects of controlled ovarian hyperstimulation (COH) for IVF in terms of breast cancer risk remain controversial, despite the hormone-dependent nature of the latter.

METHODS

Eligible studies up to 15 February 2013 were identified and pooled effect estimates for relative risk (RR) were calculated separately for the investigations using the general population and those using infertile women, as a reference group. Fixed- or random-effects models were implemented and subgroup analyses were performed, as appropriate.

RESULTS

Eight cohort studies were synthesized, yielding a total cohort size of 1,554,332 women among whom 14,961 incident breast cancer cases occurred, encompassing 576 incident breast cancer cases among women exposed to IVF. No significant association between IVF and breast cancer was observed either in the group of studies treating the general population (RR = 0.91, 95% confidence interval (CI): 0.74-1.11) or infertile women (RR = 1.02, 95% CI: 0.88-1.18), as a reference group. Of note were the marginal associations, protective for pregnant and/or parous women after IVF (pooled effect estimate = 0.86, 95% CI: 0.73-1.01) and adverse for women <30 years at first IVF treatment (pooled effect estimate = 1.64, 95% CI: 0.96-2.80).

CONCLUSIONS

At present, COH for IVF does not seem to impart increased breast cancer risk. Longer follow-up periods, comparisons versus infertile women, subgroup analyses aiming to trace vulnerable subgroups, adjustment for various confounders and larger informative data sets are needed before conclusive statements for the safety of the procedure are reached.