Obstetric and neonatal outcomes in blastocyst-stage biopsy with frozen embryo transfer and cleavage-stage biopsy with fresh embryo transfer after preimplantation genetic diagnosis/screening

Adverse maternal and neonatal outcomes of preimplantation genetic testing with trophectoderm biopsy: a retrospective cohort study of 3373 intracytoplasmic sperm injection single frozen-thawed blastocyst transfer cycles

PURPOSE

To investigate whether trophectoderm biopsy increases the risk of adverse maternal and neonatal outcomes in intracytoplasmic sperm injection (ICSI) single frozen-thawed blastocyst transfer cycles.

METHODS

This respective cohort study enrolled 3373 ICSI single frozen-thawed blastocyst transfer cycles with and without trophectoderm biopsy. Statistical methods including univariate logistic regression analysis, multivariate logistic regression analysis, and stratified analyses were performed to explore the impact of trophectoderm biopsy on adverse maternal and neonatal outcomes.

RESULTS

The rates of adverse maternal and neonatal outcomes were comparable between the two groups. Univariate analysis showed that the live birth rate (45.15% vs. 40.75%; P = 0.010) in the biopsied group was statistically higher than that in the unbiopsied group, and the rates of miscarriage (15.40% vs. 20.00%; P = 0.011) and birth defects (0.58% vs. 2.16%; P = 0.007) were statistically lower in the biopsied group. After adjusting for confounding factors, the rates of miscarriage (aOR = 0.74; 95% CI = 0.57-0.96; P = 0.022) and birth defects (aOR = 0.24, 95% CI = 0.08-0.70, P = 0.009) in the biopsied group were significantly lower than those in the unbiopsied group. Stratified analyses showed that the birth defects rate after biopsy was significantly reduced in the subgroups of age < 35 years old, BMI ≥ 24 kg/m2, artificial cycle with downregulation, poor-quality blastocysts, and Day 5 poor-quality blastocysts.

CONCLUSION

Preimplantation genetic testing (PGT) with trophectoderm biopsy does not increase the risk of adverse maternal and neonatal outcomes in ICSI single frozen-thawed blastocyst transfer cycles, and PGT can effectively reduce the rates of miscarriage and birth defects.

Preimplantation genetic testing for aneuploidy is not related to adverse obstetric and neonatal outcomes in singleton pregnancies

STUDY QUESTION

What is the potential impact of preimplantation genetic testing for aneuploidy (PGT-A) on obstetric and neonatal outcomes?

SUMMARY ANSWER

PGT-A is not associated with increased rates of adverse maternal and neonatal outcomes in singleton pregnancies following IVF/ICSI cycles.

WHAT IS KNOWN ALREADY

PGT-A pregnancies may be associated with increased risks of lower birthweight, preterm delivery, and hypertensive disorders compared with natural pregnancies. In a recent meta-analysis, the overall obstetric and neonatal outcomes of PGT-A pregnancies were favorable compared with those of IVF/ICSI pregnancies, although PGT-A pregnancies were associated with a higher risk of hypertensive disorders.

STUDY DESIGN, SIZE, DURATION

A multicenter retrospective cohort study was performed in University-affiliated infertility centers. Single live births following IVF/ICSI between October 2016 and January 2021 were included in the study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 7146 live births after single embryo transfers with (n = 3296) or without (n = 3850) PGT-A were included. The primary outcome was pre-eclampsia and secondary outcomes included gestational diabetes, low birthweight and very low birthweight, cesarean section delivery, emergency cesarean section, as well as preterm birth, birthweight, congenital abnormalities, neonatal sex, Apgar score at 5 min, and neonatal intensive care unit admission. In a subgroup analysis, were included only blastocysts screened with next-generation sequencing (NGS).

MAIN RESULTS AND THE ROLE OF CHANCE

Univariate analysis showed that pre-eclampsia, cesarean section incidence, and low Apgar score were higher in women undergoing PGT-A. However, after performing multivariate logistic and linear regression models accounting for many possible confounders, pregnancies that had been conceived after embryo biopsy showed no increase in adverse obstetric and neonatal outcomes. The subgroup analysis including patients with blastocysts screened by NGS showed a decreased risk of preterm birth in the group undergoing PGT-A.

LIMITATIONS, REASONS FOR CAUTION

Caution should be used when interpreting the data because of its limitations, mainly related to its retrospective design. Although this is a large multicenter study, data acquisition included self-reporting questionnaires, and the deliveries occurred in different institutions with distinct protocols.

WIDER IMPLICATIONS OF THE FINDINGS

The current study does not show any major adverse clinical outcomes after PGT-A. Efforts should be made to promote good quality research on embryo biopsy in terms of neonatal and obstetric outcomes, as well as its long-term consequences.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was obtained for this study. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Day 5 versus day 3 embryo biopsy for preimplantation genetic testing for monogenic/single gene defects

BACKGROUND

Assisted reproductive technology (ART) has allowed couples with a family history of a monogenic genetic disease, or a disease-carrying gene, to reduce the chance of them having a child with the genetic disorder. This is achieved by genetically testing the embryos using an advanced process called preimplantation genetic testing for monogenic or single gene disorders (PGT-M), such as Huntington's disease or cystic fibrosis. This current terminology (PGT-M) has replaced the formerly-known preimplantation genetic diagnosis (PGD). During PGT-M, one or more embryo cells are biopsied and analysed for genetic or chromosomal anomalies before transferring the embryos to the endometrial cavity. Biopsy for PGT-M can be performed at day 3 of cleavage-stage embryo development when the embryo is at the six- to the eight-cell stage, with either one or two blastomeres being removed for analysis. Biopsy for PGT-M can also be performed on day 5 of the blastocyst stage of embryo development when the embryo has 80 to 100 cells, with five to six cells being removed for analysis. Day 5 biopsy has taken over from day 3 biopsy as the most widely-used biopsy technique; however, there is a lack of summarised evidence from randomised controlled trials (RCTs) that assesses the effectiveness and safety of day 5 biopsy compared to day 3 biopsy. Since biopsy is an invasive process, whether it is carried out at day 3 or day 5 of embryo development may have different impacts on further development, implantation, pregnancy, live birth and perinatal outcomes.

OBJECTIVES

To assess the benefits and harms of day 5 embryo biopsy, in comparison to day 3 biopsy, in PGT-M in women undergoing in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) cycles.

SEARCH METHODS

We searched the following electronic bibliographic databases in December 2021 to identify relevant RCTs: the Cochrane Gynaecology and Fertility Group (CGFG) Specialised Trials Register; CENTRAL, MEDLINE, Embase and PsycINFO. We also handsearched grey literature, such as trial registers, relevant journals, reference lists, Google Scholar, and published conference abstracts.

SELECTION CRITERIA

Eligible RCTs compared day 5 versus day 3 embryo biopsy for PGT-M.  DATA COLLECTION AND ANALYSIS: We used standard methodological procedures recommended by Cochrane. The primary review outcomes were live births and miscarriages. We calculated outcomes per woman/couple randomised and reported odds ratios (ORs) with 95% confidence intervals (CIs).

MAIN RESULTS

We included one RCT involving 20 women. The evidence was of very low certainty; the main limitations of the study were serious risk of bias due to lack of blinding of study personnel, and imprecision. We are uncertain whether day 5 embryo biopsy compared to day 3 biopsy has an effect on live births (OR 1.50, 95% CI 0.26 to 8.82; 1 RCT, 20 women; very low-certainty evidence). The evidence suggests that if the chance of live birth following day 3 biopsy was assumed to be 40%, then the chance with day 5 biopsy is between 15% and 85%. It is also uncertain whether day 5 embryo biopsy compared to day 3 biopsy has an effect on miscarriages (OR 1.00, 95% CI 0.05 to 18.57; 1 RCT, 20 women; very low-certainty evidence).  We are uncertain whether day 5 embryo biopsy compared to day 3 biopsy has an effect on other secondary outcome measures, including viable intrauterine pregnancies (OR 2.25, 95% CI 0.38 to 13.47; 1 RCT, 20 women; very low-certainty evidence), ectopic pregnancies (OR 0.16, 95% CI 0.01 to 3.85; 1 RCT, 20 women; very low-certainty evidence), stillbirths (OR not estimable as no events in either group; 1 RCT, 20 women; very low-certainty evidence) or termination of pregnancies (OR 3.32, 95% CI 0.12 to 91.60; 1 RCT, 20 women; very low-certainty evidence). No studies reported on gestational age at birth, birthweight, neonatal mortality and major congenital anomaly.

AUTHORS' CONCLUSIONS

We are uncertain if there is a difference in live births and miscarriages, viable intrauterine pregnancies, ectopic pregnancies, stillbirths or termination of pregnancies between day 5 and day 3 embryo biopsy for PGT-M. There was insufficient evidence to draw any conclusions regarding other adverse outcomes. The results should be interpreted with caution, as the evidence was of very low certainty due to limited studies, high risk of bias in the included study, and an overall low level of precision.

Endometrial thickness is an independent risk factor of hypertensive disorders of pregnancy: a retrospective study of 13,458 patients in frozen-thawed embryo transfers

BACKGROUND

Hypertensive disorders of pregnancy (HDP) are an important cause of maternal and fetal mortality, and its potential risk factors are still being explored. Endometrial thickness (EMT), as one of the important monitoring indicators of endometrial receptivity, has been confirmed to be related to the incidence of HDP in fresh embryo transfer. Our study was designed to investigate whether endometrial thickness is associated with the risk of hypertensive disorders of pregnancy in frozen-thawed embryo transfer (FET).

METHODS

This respective cohort study enrolled 13,458 women who received vitrified embryo transfer and had a singleton delivery in the Reproductive Hospital affiliated to Shandong University from January 2015 to December 2019. We set strict screening criteria and obtained the information from the hospital electronic medical system. Statistical methods including logistic regression analysis, receiver operating characteristic curve and restricted cubic spline were used to evaluate the relationship between endometrial thickness and the incidence of pregnancy-induced hypertension.

RESULTS

The incidences of HDP in a thin endometrial thickness group (< 0.8 cm) and a thick endometrial thickness group (> 1.2 cm) were significantly greater than in a reference group (0.8 cm-1.2 cm) (7.98 and 5.24% vs 4.59%, P <  0.001). A nonlinear relationship between endometrial thickness and risk of hypertensive disorders of pregnancy was examined by restricted cubic spline (P <  0.001). The thin endometrial thickness and thick endometrial thickness groups were significantly associated with the risk of HDP after adjusting for confounding variables by stepwise logistic regression analysis. Subsequently, subgroup logistic regression analysis based on endometrial preparation regimens showed that thin endometria were still significantly associated with a higher morbidity rate in the artificial cycle group, while in the natural cycle group, thick endometria were closely associated with increased morbidity.

CONCLUSION

Our study manifested that both the thin and thick endometria were associated with an increased risk of hypertensive disorders of pregnancy in frozen embryo transfer cycles. Reproductive clinicians should focus on adjusting endometrial thickness in different preparation regimens; and obstetricians should be mindful of the risk of hypertension during pregnancy, when women with thin (< 0.8 cm) or excessively thicker (> 1.2 cm) endometrial thickness achieve pregnancy through frozen-thawed embryo transfer.

Placental Dysfunction in Assisted Reproductive Pregnancies: Perinatal, Neonatal and Adult Life Outcomes

Obstetric and newborn outcomes of assisted reproductive technology (ART) pregnancies are associated with significative prevalence of maternal and neonatal adverse health conditions, such as cardiovascular and metabolic diseases. These data are interpreted as anomalies in placentation involving a dysregulation of several molecular factors and pathways. It is not clear which extent of the observed placental alterations are the result of ART and which originate from infertility itself. These two aspects probably act synergically for the final obstetric risk. Data show that mechanisms of inappropriate trophoblast invasion and consequent altered vascular remodeling sustain several clinical conditions, leading to obstetric and perinatal risks often found in ART pregnancies, such as preeclampsia, fetal growth restriction and placenta previa or accreta. The roles of factors such as VEGF, GATA3, PIGF, sFLT-1, sEndoglin, EGFL7, melatonin and of ART conditions, such as short or long embryo cultures, trophectoderm biopsy, embryo cryopreservation, and supraphysiologic endometrium preparation, are discussed. Inflammatory local conditions and epigenetic influence on embryos of ART procedures are important research topics since they may have important consequences on obstetric risk. Prevention and treatment of these conditions represent new frontiers for clinicians and biologists involved in ART, and synergic actions with researchers at molecular levels are advocated.

Hypothesis: human trophectoderm biopsy downregulates the expression of the placental growth factor gene

Preeclampsia (PE) and intrauterine growth retardation (IUGR) are the results of defective placentation associated with the downregulation of different genes in the human trophoblast including the Placental Growth Factor (PGF). TrophEctoderm (TE) biopsy is increasingly performed for Pre-implantation Genetic Testing of Aneuploidies and it involves the traumatical removal of an unpredictable number of mural TE cells from the human blastocyst. We observed strikingly similar obstetrical and neonatal complications in pregnancies where the placenta bears PGF downmodulation or a TE biopsy has been done. In both groups, the risk of PE, IUGR, congenital cardiac ventricular septal defects, caesarean section, sex ratio in favour of males and preterm birth is significantly increased compared to controls. Given the high degree of correlation, the observation may not be a casual one. We postulate herein that the TE biopsy may induce persistent dysregulation of different genes in the placenta including PGF. The mechanism proposed is the disruption of tight junctions caused by the TE biopsy.

Impact of preimplantation genetic testing on obstetric and neonatal outcomes: a systematic review and meta-analysis

OBJECTIVE

To investigate whether preimplantation genetic testing (PGT) increases the risk of adverse obstetric and neonatal outcomes.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Pregnancies achieved after PGT or in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

INTERVENTION(S)

Systematic search of databases until December 2020 with cross-checking of references from relevant articles in English.

MAIN OUTCOME MEASURE(S)

Obstetric and neonatal outcomes after PGT and IVF/ICSI, including mean birth weight, low birth weight, very low birth weight (VLBW), mean gestational age at birth, preterm birth, very preterm birth, birth defects, intrauterine growth retardation (IUGR), sex ratio, cesarean section, hypertensive disorders of pregnancy, gestational diabetes mellitus, placenta disorder (placenta previa, placenta abruption, placenta accreta), and preterm premature rupture of membranes.

RESULT(S)

Ultimately, a total of 785,445 participants were enrolled in this meta-analysis, and these participants were divided into a PGT group (n = 54,294) and an IVF/ICSI group (n = 731,151). The PGT pregnancies had lower rates of low birth weight (risk ratio [RR] 0.85, 95% confidence interval [CI] 0.75 to 0.98), VLBW (RR 0.52, 95% CI 0.33 to 0.81), and very preterm births (RR 0.55, 95% CI 0.42 to 0.70) than those of IVF/ICSI pregnancies. However, the PGT group had a higher rate of the obstetric outcome of hypertensive disorders of pregnancy (RR 1.30, 95% CI 1.08 to 1.57). The PGT did not increase the risk of other adverse obstetric and neonatal outcomes, such as those associated with mean birth weight, mean gestational age at birth, birth defects, IUGR, sex ratio, cesarean section, gestational diabetes mellitus, placental disorder (placenta previa, placenta abruption, placenta accreta), or preterm premature rupture of membranes. We performed subgroup analysis with only blastocyst biopsies and found that PGT with blastocyst biopsies was associated with a lower rate of VLBW (RR 0.55, 95% CI 0.31 to 0.95). The PGT with blastocyst biopsies did not increase the risk of other adverse obstetric and neonatal outcomes. Additionally, we performed subgroup analysis with only frozen-thawed embryo transfer cycles, and we found that PGT pregnancies were associated with a lower rate of VLBW (RR 0.55, 95% CI 0.31 to 0.97), a lower rate of cesarean birth (RR 0.90, 95% CI 0.82 to 0.99), a higher rate of preterm birth (RR 1.10, 95% CI 1.02 to 1.18), and a higher rate of IUGR (RR 1.21, 95% CI 1.06 to 1.38) than those of IVF/ICSI pregnancies. The PGT with frozen-thawed embryo transfer did not increase the risk of other adverse obstetric and neonatal outcomes.

CONCLUSION(S)

The pooled analysis suggested that PGT did not increase the risk of adverse obstetric outcomes. The association between PGT and a higher risk of IUGR requires further investigation.

Impact of trophectoderm biopsy on obstetric and perinatal outcomes following frozen-thawed embryo transfer cycles

STUDY QUESTION

Does trophectoderm biopsy for preimplantation genetic testing (PGT) increase the risk of obstetric or perinatal complications in frozen-thawed embryo transfer (FET) cycles?

SUMMARY ANSWER

Trophectoderm biopsy may increase the risk of hypertensive disorders of pregnancy (HDP) in pregnancies following FET cycles.

WHAT IS KNOWN ALREADY

Trophectoderm biopsy has replaced blastomere biopsy as the standard of care to procure cells for PGT analysis. Recently, there has been concern that trophectoderm biopsy may adversely impact obstetric and perinatal outcomes. Previous studies examining this question are limited by use of inappropriate control groups, small sample size or reporting on data that no longer reflects current IVF practice.

STUDY DESIGN, SIZE, DURATION

This was a retrospective cohort study conducted at a single university-affiliated fertility center. A total of 756 patients who underwent FET with transfer of previously vitrified blastocysts that had either trophectoderm biopsy or were unbiopsied and resulted in a singleton live birth between 2013 and 2019 were included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Obstetric and perinatal outcomes for patients aged 20-44 years who underwent FET with transfer of previously vitrified blastocysts that were either biopsied (n = 241) or unbiopsied (n = 515) were analyzed. Primary outcome was odds of placentation disorders including HDP and rate of fetal growth restriction (FGR). Binary logistic regression was performed to control for potential covariates.

MAIN RESULTS AND THE ROLE OF CHANCE

The biopsy group was significantly older, had fewer anovulatory patients, was more often nulliparous and had fewer embryos transferred compared to the unbiopsied group. After controlling for potential covariates, the probability of developing HDP was significantly higher in the biopsy group compared with unbiopsied group (adjusted odds ratio (aOR) 1.943, 95% CI 1.072-3.521; P = 0.029).There was no significant difference between groups in the probability of placenta previa or placenta accreta. There was also no significant difference in the rate of FGR (aOR 1.397; 95% CI, 0.815-2.395; P = 0.224) or the proportion of low (aOR 0.603; 95% CI, 0.336-1.084; P = 0.091) or very low (aOR 2.948; 95% CI, 0.613-14.177; P = 0.177) birthweight infants comparing biopsied to unbiopsied groups.

LIMITATIONS, REASON FOR CAUTION

This was a retrospective study performed at a single fertility center, which may limit the generalizability of our findings.

WIDER IMPLICATIONS OF THE FINDINGS

Trophectoderm biopsy may increase the risk of HDP in FET cycles, however, a prospective multicenter randomized trial should be performed to confirm these findings.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was obtained for this study. The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

NA.

Review: Preimplantation genetic diagnosis (PGD) as a reproductive option in patients with neurodegenerative disorders

Preimplantation genetic diagnosis (PGD) was introduced in the late 1980s and represents an option for couples at risk of transmitting an inherited, debilitating or neurological disorder to their children. From a cleavage or blastocyst stage embryo, cell(s) are collected and then genetically analyzed for disease; enabling an unaffected embryo to be transferred into the uterus cavity. Nowadays, PGD has been carried out for several hundreds of heritable conditions including myotonic dystrophy, and for susceptibility genes involved in cancers of the nervous system. Currently, advanced molecular technologies with better resolution, such as array comparative genomic hybridisation, quantitative polymerase chain reaction, and next generation sequencing, are on the verge of becoming the gold standard in embryo preimplantation screening. Given this, it may be time for neurological societies to consider the published evidence to develop new guidelines for the integration of PGD into modern preventative neurology. Therefore, the main aim of this review is to illustrate the option of PGD to enable conception of an unaffected baby, and to assist clinicians and neurologists in the counseling of the patient at risk of transmitting an inherited disease, to explore the genetic journey throughout in vitro fertilization IVF with PGD.

Perinatal and obstetric outcomes in singleton pregnancies following fresh versus cryopreserved blastocyst transfer: a meta-analysis

The transfer of cryopreserved blastocysts is increasing in IVF centres. However, little is known about the perinatal and obstetric outcomes of this procedure. In an attempt to further elucidate these issues, a systematic review and meta-analysis was conducted to compare cryopreserved transfer with fresh blastocyst embryo transfer. The results show that the risk of both preterm (odds ratio [OR] 0.89, 95% confidence interval [CI] 0.80-0.99, P = 0.04) and low birthweight births (OR 0.82, 95% CI 0.68-0.99, P = 0.04) was significantly lower after cryopreserved blastocyst transfer than after fresh blastocyst transfer. The rate of large for gestational age births was significantly higher (OR 1.68, 95% CI 1.55-1.82, P < 0.00001) and the rate of small for gestational age births significantly lower (OR 0.59, 95% CI 0.54-0.65, P < 0.00001) after cryopreserved blastocyst transfer. The transfer of cryopreserved blastocysts was associated with a significantly lower risk of placental abruption (OR 0.58, 95% CI 0.40-0.83, P = 0.003) but a significantly higher risk of Caesarean section (OR 1.21, 95% CI 1.01-1.43, P = 0.03). In conclusion, the perinatal and obstetric outcomes associated with the transfer of cryopreserved blastocysts differ from those associated with fresh blastocyst transfer.

Uterine artery Doppler in singleton pregnancies conceived after in-vitro fertilization or intracytoplasmic sperm injection with fresh vs frozen blastocyst transfer: longitudinal cohort study

OBJECTIVE

Pregnancies conceived by frozen blastocyst transfer (FBT) have higher gestational age and weight at birth as compared to those derived by fresh blastocyst transfer. The aim of this study was to evaluate uterine artery pulsatility index (UtA-PI) in pregnancies conceived by in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) techniques using fresh vs cryopreserved blastocysts.

METHODS

This was a prospective longitudinal study of viable singleton IVF/ICSI pregnancies conceived after FBT or fresh blastocyst transfer, that underwent serial ultrasound assessment at San Raffaele Hospital, Milan, Italy at 7-37 gestational weeks. We excluded pregnancies conceived using other assisted reproductive techniques such as egg donation, twin gestation, pregnancy with abnormality and those resulting in miscarriage. Pregnant women underwent ultrasound assessment at 7-10, 11-14, 18-25 and 26-37 weeks' gestation. Mean UtA-PI was measured using Doppler ultrasound according to The Fetal Medicine Foundation criteria. Pregnancy outcomes were recorded. The primary outcome was mean UtA-PI measurement and secondary outcomes were gestational age at birth, birth weight and fetal and maternal complications, including small-for-gestational age (SGA), pre-eclampsia and large-for-gestational age. UtA-PI values were made Gaussian after log₁₀ transformation. Analysis of repeated measures using a multilevel linear mixed model (fixed effects and random effects) was performed. The possible effect of other covariates on UtA-PI Doppler values, including body mass index, SGA and pre-eclampsia, was also evaluated.

RESULTS

A total of 367 IVF/ICSI cycles, comprising 164 with fresh blastocyst transfer and 203 with FBT, were included and a total of 625 observations (median, 2.5 (range, 1-4)) were collected and analyzed. The FBT group had on average 14% lower UtA-PI compared with the fresh-blastocyst-transfer group. In pregnancies with SGA fetuses, UtA-PI was 18% higher compared to pregnancies without, irrespective of the study group. Pregnancies that underwent fresh blastocyst transfer had significantly lower birth-weight centile (43.4 ± 23.3 vs 50.0 ± 23.1; P = 0.007) and a higher rate of SGA (7.9% vs 2.0%; P = 0.008) compared to those that underwent FBT. No significant differences were found between the two groups with respect to gestational age at birth and rates of preterm birth, pre-eclampsia, gestational diabetes mellitus and large-for-gestational age.

CONCLUSION

UtA-PI and the proportion of SGA are lower in IVF/ICSI pregnancies conceived after FBT as compared to fresh blastocyst transfer. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Timing day-3 vitrification for PGT-M embryos: pre- or post-blastomere biopsy?

PURPOSE

To assess the efficacy and clinical outcomes of preimplantation genetic testing for monogenic diseases (PGT-M), following blastomere biopsy prior or following vitrification.

METHODS

A cohort-historical study of all consecutive patients admitted to IVF in a large tertiary center for PGT-M and PCR cycle from September 2016 to March 2020. Patients were divided into 4 groups: Group A1 consisted of patients undergoing day-3 embryos biopsy followed by a fresh transfer of unaffected embryos. Group A2 consisted of Group A1 patients that their surplus unaffected embryos were vitrified, thawed, and transferred in a subsequent FET cycle. Group B1 consisted of patients that their day-3 embryos were vitrified intact (without biopsy) for a subsequent FET cycle. Later embryos were thawed and underwent blastomere biopsies, and the unaffected embryos were transferred, while the surplus unaffected embryos were re-vitrified for a subsequent FET cycle. Group B2 consisted of Group B1 patients that their surplus unaffected embryos were re-vitrified, thawed, and transferred in a subsequent FET cycle. The laboratory data and clinical results were collected and compared between groups.

RESULTS

A total of 368 patients underwent 529 PGT-M cycles in our center: 347 with day-3 embryos biopsied before undergoing vitrification (Group A1) and 182 following vitrification and thawing (Group B1). There were no between group differences in embryo survival rate post-thawing, nor the ongoing implantation and pregnancy rates.

CONCLUSION

In PGT-M cycles, the timing of embryos vitrification, whether prior or following blastomere biopsy, has no detrimental effect on post-thawing embryo survival rate, nor their potential ongoing implantation and pregnancy rates.

Trophectoderm biopsy reduces the level of serum β-human chorionic gonadotropin in early pregnancy

OBJECTIVE

To assess whether trophectoderm biopsy has any impact on the level of serum β-human chorionic gonadotropin (β-hCG) in early pregnancies.

DESIGN

Retrospective cohort study.

SETTING

University-affiliated reproductive medical center.

PATIENT(S)

Three hundred and eighty-three women undergoing 396 frozen embryo transfer (FET) cycles with preimplantation genetic testing (PGT), and 353 women undergoing 465 FET cycles with in vitro fertilization or intracytoplasmic sperm injection, all women having positive serum β-hCG results on the 12th day after blastocysts transfers.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Serum β-hCG levels on the 12th day after warmed blastocyst transfer and perinatal outcomes of clinical pregnancy.

RESULTS

The diagnostic threshold of serum β-hCG levels on the 12th day after FET for prediction of a live birth was 368.55 mIU/mL with an area under the curve of 0.791 (0.729∼0.853) in the biopsy group, which was lower than the 411.45 mIU/mL in the control group. The average level of serum β-hCG in the biopsy group with clinical pregnancies was statistically significantly lower than that of the control group: 703.10 (569.63) versus 809.20 (582.00), respectively. No statistically significant differences in perinatal outcomes, including gestational age, hypertensive disorder in pregnancy, and neonatal malformation, were found between the two groups.

CONCLUSION(S)

Trophectoderm biopsy may reduce the level of serum β-hCG in early pregnancies (the 12th day after embryo transfer), but no increased risk was found of adverse perinatal outcomes after trophectoderm biopsy.

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.

A blastocyst biopsy approach for preimplantation genetic diagnosis technique that affects the expression of SNAP-α in mice

Preimplantation genetic diagnosis (PGD) is a technique that is commonly used during assisted reproduction in the clinics to eliminate genetically abnormal embryos before implantation. The blastomere biopsy technique has risks related to the embryo, but blastocyst biopsy has not been systematically evaluated in relation to effects after birth, and the resulting offspring have not been followed up on. We designed a series of experiments to evaluate the risk of blastocyst biopsy on the resulting progeny. Mice were divided into a PGD group and a control group. The former was the progeny of mice that underwent blastocyst biopsy and the latter was delivered through a normal pregnancy without blastocyst biopsy. Each group consisted of 15 animals. We found no effects of blastocyst biopsy on reproductive capacities and weight gain. As for neurobehavioral evaluation between both groups, there were no significant differences in tail suspension test, sucrose preference test, the open field test and the elevated plus maze. Western blotting, immunohistochemistry and quantitative RT-PCR results showed that the expression levels of MBP, PRDX5 and UCHL1 in the PGD group were not significantly different compared to the control group, but SNAP-α expression in the PGD group was lower than that in control group. In summary, we concluded that blastocyst biopsy had no adverse effect on the general growth and behavior in mice. However, blastocyst biopsy effected the expression of SNAP-α. Therefore, the safety of blastocyst biopsy requires further evaluation.

Maternal and neonatal outcomes associated with trophectoderm biopsy

OBJECTIVE

To assess whether pregnancies achieved with trophectoderm biopsy for preimplantation genetic testing (PGT) have different risks of adverse obstetric and neonatal outcomes compared with pregnancies achieved with IVF without biopsy.

DESIGN

Observational cohort.

SETTING

University-affiliated fertility center.

PATIENT(S)

Pregnancies achieved via IVF with PGT (n = 177) and IVF without PGT (n = 180) that resulted in a live birth.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Maternal outcomes including preeclampsia and placenta previa and neonatal outcomes including birth weight and birth defects.

RESULT(S)

There was a statistically significant increase in the risk of preeclampsia among IVF+PGT pregnancies compared with IVF without PGT pregnancies, with an incidence of 10.5% versus 4.1% (adjusted odds ratio [aOR] = 3.02; 95% confidence interval [95% CI], 1.10, 8.29). The incidence of placenta previa was 5.8% in IVF+PGT pregnancies versus 1.4% in IVF without PGT pregnancies (aOR = 4.56; 95% CI, 0.93, 22.44). Similar incidences of gestational diabetes, preterm premature rupture of membranes, and postpartum hemorrhage were observed. IVF+PGT and IVF without PGT neonates did not have a significantly different gestational age at delivery or rate of preterm birth, low birth weight, neonatal intensive care unit admission, neonatal morbidities, or birth defects. All trends, including the significantly increased risk of preeclampsia in IVF+PGT pregnancies, persisted upon stratification of analysis to only singleton live births.

CONCLUSION(S)

To date, this is the largest and most extensively controlled study examining maternal and neonatal outcomes after trophectoderm biopsy. There was a statistically significant three-fold increase in the odds of preeclampsia associated with trophectoderm biopsy. Given the rise in PGT use, further investigation is warranted.

Increased pregnancy complications following frozen-thawed embryo transfer during an artificial cycle

PURPOSE

This study aimed to clarify the risks of adverse pregnancy outcomes in patients and their offspring after frozen embryo transfer (FET) during an artificial cycle (AC).

METHODS

We conducted a retrospective cohort study that included all FET cycles and subsequent deliveries in a single centre between August 2013 and March 2016. Pregnancy, obstetric and neonatal outcomes were compared among patients treated during an AC or a natural cycle with luteal phase support (NC-LPS). Multivariate logistic regression was performed to evaluate the relationship between endometrial preparation schemes and pregnancy, obstetric and neonatal outcomes.

RESULTS

AC-FET was not a significant risk factor for clinical pregnancy rate, multiple birth rate or miscarriage rate after adjusting for potential confounders. However, AC-FET was a significant risk factor for ectopic pregnancy rate (adjusted odds ratio (AOR), 1.738; 95% confidence interval (CI), 1.086-2.781) and live birth rate (AOR, 0.709; 95% CI, 0.626-0.802). Regarding obstetric outcomes, AC-FET was found to be associated with an increased risk for hypertension disorder (AOR, 1.780; 95% CI, 1.262-2.510) and caesarean section (AOR, 1.507; 95% CI, 1.195-1.900). In multiples, birth weight (2550 g (2150-2900 g) in AC-FET vs. 2600 g (2350-2900 g) in NC-LPS; P = 0.023), gestational age (36.6 weeks (35.3-37.6 weeks) vs. 37.1 weeks (36.1-37.9 weeks); P < 0.001), and z-score (- 0.5 (- 1.1, - 0.0) vs. - 0.4 (- 1.0, 0.2); P = 0.009) were higher in the NC-LPS group than in the AC-FET group, although there were no differences in these variables among singletons.

CONCLUSION

Compared with NC-LPS, AC-FET seemed to have a negative effect on obstetric outcomes.

Risk of adverse pregnancy and perinatal outcomes after high technology infertility treatment: a comprehensive systematic review

In the literature, there is growing evidence that subfertile patients who conceived after infertility treatments have an increased risk of pregnancy and perinatal complications and this is particularly true for patients who conceived through use of high technology infertility treatments. Moreover, high technology infertility treatments include many concomitant clinical and biological risk factors. This review aims to summarize in a systematic fashion the current evidence regarding the relative effect of the different procedures for high technology infertility treatments on the risk of adverse pregnancy and perinatal outcome. A literature search up to August 2016 was performed in IBSS, SocINDEX, Institute for Scientific Information, PubMed, Web of Science and Google Scholar and an evidence-based hierarchy was used to determine which articles to include and analyze. Data on prepregnancy maternal factors, low technology interventions, specific procedures for male factor, ovarian tissue/ovary and uterus transplantation, and chromosomal abnormalities and malformations of the offspring were excluded. The available evidences were analyzed assessing the level and the quality of evidence according to the Oxford Centre for Evidence-Based Medicine guidelines and the Grading of Recommendations Assessment, Development, and Evaluation system, respectively. Current review highlights that every single procedure of high technology infertility treatments can play a crucial role in increasing the risk of pregnancy and perinatal complications. Due to the suboptimal level and quality of the current evidence, further well-designed studies are needed.