Preimplantation genetic testing for aneuploidy in severe male factor infertility

Impact of blastocyst biopsy for preimplantation genetic testing on maternal and neonatal outcomes following single frozen embryo transfer cycles

BACKGROUND

Up to now, a number of studies have explored the influence of blastocyst biopsy on maternal and neonatal outcomes, and the results have been somewhat inconsistent. Therefore, the aim of this study was to investigate whether blastocyst biopsy is associated with an elevated risk of hypertensive disorders of pregnancy (HDP) and other adverse perinatal outcomes during frozen embryo transfer (FET) cycles in singleton live births resulting from intracytoplasmic sperm injection (ICSI) in women aged ≤ 35 years.

METHODS

A total of 1,008 women were involved in this study from January 2020 to June 2022, who underwent ICSI cycles and received single FET, leading to the birth of a live singleton newborn. The study population were categorized into two groups: the preimplantation genetic testing (PGT) group, comprising 269 women whose blastocysts underwent trophectoderm biopsy, and the control group, consisting of 739 women whose blastocysts did not undergo biopsy. The primary outcome assessed in this study was HDP. Additionally, various relevant perinatal outcomes related to both maternal and neonatal health were also evaluated.

RESULTS

In comparison to the control group, notable disparities were observed between the groups in relation to infertility duration, EMT, infertility type, infertility cause and endometrial preparation protocol (P < 0.05, for all). The percentage of female gender significantly increased in the PGT group in comparison with the control group (P < 0.05). However, the risk of HDP, other maternal and neonatal outcomes exhibited comparable results between the two groups (P > 0.05, for all). Moreover, univariate regression analyses further revealed that PGT had no influence on maternal and neonatal outcomes, except for gender (aOR 1.44; 95% CI, 1.03-2.01; P = 0.031).

CONCLUSIONS

In the short-term perspective, it could be inferred that blastocyst biopsy may not increase the risks associated with HDP or other unfavorable maternal and neonatal outcomes. However, despite the limited sample size, our findings may not be applicable to those aged 35 or over; therefore, larger cohort studies are imperative for the validation of our results.

The use of preimplantation genetic testing for aneuploidy: a committee opinion

The use of preimplantation genetic testing for aneuploidy (PGT-A) in the United States has been increasing steadily. Moreover, the underlying technology used for 24-chromosome analysis continues to evolve rapidly. The value of PGT-A as a routine screening test for all patients undergoing in vitro fertilization has not been demonstrated. Although some earlier single-center studies reported higher live-birth rates after PGT-A in favorable-prognosis patients, recent multicenter, randomized control trials in women with available blastocysts concluded that the overall pregnancy outcomes via frozen embryo transfer were similar between PGT-A and conventional in vitro fertilization. The value of PGT-A to lower the risk of clinical miscarriage is also unclear, although these studies have important limitations. This document replaces the document of the same name, last published in 2018.

Mitochondrial DNA Content May Not Be a Reliable Screening Biomarker for Live Birth After Single Euploid Blastocyst Transfer

An increasing number of studies have related the mitochondrial DNA (mtDNA) content to embryo viability and transfer outcomes. However, previous studies have focused more on the relationship between mtDNA and embryo implantation, few studies have studied the effect of the mtDNA content on live birth. In the study, we investigated whether mtDNA content is a reliable screening biomarker for live birth after single blastocyst transfer. A total of 233 couples with 316 blastocyst stage embryos undergoing in vitro fertilization treatment and pre-implantation genetic testing analysis were included in the study. All embryos were chromosomally normal and had undergone single-embryo transfers. There was no significant difference observed in the blastocyst mtDNA content among the live birth, miscarriage and non-implanted groups (p=0.999), and the mtDNA content in blastocysts from the miscarriage and live birth groups was similar [median (interquartile range), 1.00*10⁸(7.59*10⁷- 1.39*10⁸) vs 1.01*10⁸ (7.37*10⁷- 1.32*10⁸)]. Similarly, no significant association was observed between mtDNA content and embryo implantation potential (p=0.965). After adjusting for multiple confounders in a logistic regression analysis with generalized estimating equations, no associations between mtDNA content and live birth were observed in all blastocysts, Day-5 and Day-6 blastocysts (p=0.567, p=0.673, p=0.165, respectively). The live birth rate was not significantly different between blastocysts with an elevated mtDNA content and blastocysts with a normal mtDNA content (26.7% vs 33.6% p=0.780). Additionally, there was no linear correlation between the mtDNA content and maternal age (p=0.570). In conclusion, the mtDNA content does not seem to be a potential biomarker for embryo transfer outcomes (i.e., implantation and live birth) based on the existing testing tools. Embryos with an elevated mtDNA content also have development potential for successful live birth.