What should we focus on before preimplantation genetic diagnosis/screening?

Antimüllerian hormone (AMH) and age as predictors of preimplantation genetic testing for aneuploidies (PGT-A) cycle outcomes and blastocyst quality on day 5 in women undergoing in vitro fertilization (IVF)

PURPOSE

The objective of this study was to investigate whether women with diminished ovarian reserve who planned for PGT-A exhibit a lower number of blastocysts for biopsy, ploidy outcomes, and blastocyst quality on day 5, regardless of age.

METHODS

A retrospective analysis was performed between March 2017 and July 2020 at ART Fertility Clinics Abu Dhabi, including couples that were triggered for final oocyte maturation in an ovarian stimulated cycle planned for PGT-A. Patients were stratified into four AMH groups: < 0.65 ng/ml, 0.65-1.29 ng/ml, 1.3-6.25 ng/ml, and > 6.25 ng/ml; four age categories: ≤ 30, 31-35, 36-40, and > 40 years.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 1410 couples with a mean maternal age of 35.2 ± 6.4 years and AMH of 2.7 ± 2.6 ng/ml were included. In a multivariate logistic regression analysis, controlling for age, the chance of having at least one blastocyst biopsied/stimulated cycle (1156/1410), the chance of having at least one euploid blastocyst/stimulated cycle (880/1410), and the chance of having one euploid blastocyst once biopsy was performed (880/1156) were affected in all patients with AMH < 0.65 ng/ml [AdjOR 0.18[0.11-0.31] p = 0.008)], [AdjOR 0.18 [0.11-0.29] p < 0.001], and [AdjOR 0.34 [0.19-0.61] p = 0.015] as well as in patients with AMH 0.65-1.29 ng/ml (AdjOR 0.52 [0.32-0.84] p < 0.001), (AdjOR 0.49 [0.33-0.72] p < 0.001), and (AdjOR 0.57 [0.36-0.90] p < 0.001), respectively. In a multivariate linear regression analysis, AMH values did not affect blastocyst quality (- 0.72 [- 1.03 to - 0.41] p < 0.001).

CONCLUSION

Irrespective of age, patients with diminished ovarian reserve (AMH < 1.3 ng/ml) have a lower chance of having at least one blastocyst biopsied and lower chance of having at least one euploid blastocyst per ovarian stimulated cycle. Blastocyst quality was not affected by AMH values.

Clinical Outcome, Socioeconomic Status and Psychological Constrains of Patients Undergoing Preimplantation Genetic Testing (PGT) in Northern Greece

Background and objectives: Preimplantation genetic testing (PGT) offers patients the possibility of having a healthy baby free of chromosomal or genetic disorders. The present study focuses on the application of PGT for patients located in Northern Greece, investigating their clinical outcomes, their motives, and their overall physical and emotional experience during the treatment, in association with their socioeconomic background. Materials and Methods: Couples who underwent PGT for a monogenic condition (PGT-M, n = 19 cycles) or aneuploidy (PGT-A, n = 22 cycles) participated in the study. Fertilization, implantation, and pregnancy rates were recorded for all cycles. The couples were asked to fill in a questionnaire about the consultation they had received prior to treatment, their sociodemographic information, and the psychological impact PGT had on both the female and male partner. Results: The fertilization, implantation, and ongoing pregnancy rates for the PGT-M and PGT-A cycles were 81.3%, 70.6%, and 52.9%, and 78.2%, 64.3%, and 57.1%, respectively. Females experienced more intense physical pain than their male partners while psychological pain was encountered by both partners and occasionally in higher instances in males. No typical socioeconomic background of the patients referred for PGT in Northern Greece was noticed. Conclusion: PGT is an attractive alternative to prenatal diagnosis (PND), aiming to establisha healthy pregnancy by identifying and avoiding the transfer of chromosomally or genetically abnormal embryos to the uterus. Although the benefits of PGT were well-received by all patients undergoing the procedure, psychological pain was evident and especially prominent in patients with a previous affected child or no normal embryos for transfer. Holistic counseling is of utmost importance in order to make patients' experience during their journey to have a healthy baby less emotionally demanding and help them make the right choices for the future.

A systematic review exploring the patient decision-making factors and attitudes towards pre-implantation genetic testing for aneuploidy and gender selection

INTRODUCTION

Pre-implantation genetic testing for aneuploidy (PGT-A) is in high demand worldwide, with ongoing debate among medical societies as to which patient groups it should be offered. The psychological aspects for patients regarding its use, lag behind the genomic technological advances, leaving couples with limited decision-making support. The development of this technology also leads to the possibility for its utilization in gender selection. Despite the controversy surrounding these issues, very few studies have investigated the psychological aspects of patients using PGT-A.

MATERIAL AND METHODS

This systematic review provides an up-to-date analysis of the psychosocial aspects surrounding PGT for aneuploidy and sex selection, as well as decision-making factors. A systematic search of English peer-reviewed journals of three computerized databases were undertaken following PRISMA guidelines. The qualitative data were extracted using thematic analysis. PROSPERO Registration number: CRD42019126439.

RESULTS

The main outcome measures were patients' motivations, decision-making factors, attitudes and experiences surrounding the use of PGT for aneuploidy and sex selection. Ten studies were included, four for PGT-A and six for sex selection. Attitudes towards PGT-A were positive, with the main motivating factors being decreasing miscarriage rate, reducing the risk of termination of pregnancy and reducing the time to pregnancy. Consistently raised concerns regarding PGT-A were the financial burden and moral beliefs. The vast majority of patients felt sufficiently knowledgeable to make the decision; however, studies did reveal that a minority mis-interpreted certain potential benefits of PGT-A. Studies investigating PGT for sex selection predominantly reported the main motivation was to achieve gender balance within the family dynamic, with most studies finding no difference between couples using PGT for gender selection to have male or female offspring.

CONCLUSIONS

Although this systematic review was limited by the small number of studies investigating this topic, a significant minority of patients appeared to misunderstand certain benefits and limitations of PGT-A. Fertility clinics must ensure they provide adequate counseling to all patients using PGT-A. With the use of PGT-A on the rise globally, there is a need to develop decision support tools for couples who have an increasing number of genetic testing options becoming available to them.

The role of total chromosomal disomy in human spermatozoa as a predictor of the outcome of pre-implantation genetic screening

OBJECTIVE

To assess the efficacy of sperm disomy rate as a predictor of preimplantation genetic screening (PGT-A) outcomes.

DESIGN

Retrospective cohort study.

SETTING

Andrology laboratory and in vitro fertilization center.

PATIENT(S)

All patients (n = 123) who underwent sperm fluorescence in situ hybridization and PGT-A at the China International Trust and Investment Corporation Xiangya Reproductive and Genetic Hospital between January 2015 and November 2018 were included.

INTERVENTION(S)

Sperm samples of all patients evaluated for elevated disomy levels of 24 chromosomes using multicolor sperm fluorescence in situ hybridization and all embryos were cultured and biopsied at the blastocyst stage for PGT-A.

MAIN OUTCOME MEASURE(S)

The relationship between the whole genome of sperm disomy rate and PGT-A outcome and the predictive effect of the whole genome of sperm disomy rate on PGT-A outcome.

RESULT(S)

A statistically significant correlation was observed between the sperm disomy rate and PGT-A outcome. Many confounders were considered, such as patients' factors, semen or laboratory characteristics, which may affect PGT-A outcome. Regression analysis excluding these confounding factors indicated a 2.071-fold decrease in odds of probability of not obtaining any euploid embryo to transfer for every 1% decrease in total disomy rate. Based on a total disomy rate threshold of 4.84%, the prediction ability of total disomy rate on PGT-A outcome reached 75.6%.

CONCLUSION(S)

There is a negative correlation between the whole genome of sperm disomy rate and PGT-A outcome. It is a potential role for whole genome of sperm disomy rate in the PGT-A patients as a predictor, as well as in future genetic counselling. Based on these results, genetic counselors can advise couples on the risk of not obtaining any euploid embryo and help them choose the best reproductive and diagnostic method.

The clinical application of preimplantation genetic diagnosis for X-linked retinitis pigmentosa

OBJECTIVE

To investigate the usefulness of preimplantation genetic diagnosis (PGD) based on mutated allele revealed by sequencing with aneuploidy and linkage analyses (MARSALA) for a pedigree with X-linked retinitis pigmentosa (XLRP).

METHODS

One pathogenic mutation (c.494G > A) of the retinitis pigmentosa GTPase regulator (RPGR) gene was identified in a pedigree affected by XLRP. Then, PGD was carried out for the couple, of which the wife was an XLRP carrier. Three blastocysts were biopsied and then MARSALA was performed by next-generation sequencing (NGS). Prenatal diagnosis was also carried out to confirm the PGD results.

RESULTS

Three blastocysts were all unaffected. Then, one of the embryos was chosen randomly to be transferred, and the pregnancy was acquired successfully. The results of prenatal diagnosis were consistent with the PGD results. The fetus did not carry RPGR mutation (c.494G > A) and had normal chromosome karyotype. As a result, a healthy baby free of XLRP condition was born.

CONCLUSION

The PGD method based on MARSALA was established and applied to a family with XLRP successfully. MARSALA will be a valid tool, not only for XLRP families but also for families affected with other monogenetic disorders, to prevent transmission of the genetic disease from parents to offspring.