Improving preimplantation genetic diagnosis (PGD) reliability by selection of sperm donor with the most informative haplotype

A clinical predictive model for live birth in women of advanced age undergoing PGT cycles

PURPOSE

The trend of delaying childbirth has resulted in a growing number of advanced-aged women who are opting for preimplantation genetic testing (PGT) to screen for monogenic diseases or structural chromosomal rearrangements (PGT-M and PGT-SR). This increase in demand necessitates the development of a clinical predictive model for live birth outcomes in these women. Therefore, the objective of this study is to construct a comprehensive predictive model that assesses the likelihood of achieving a successful live birth in advanced-aged women undergoing PGT-M and PGT-SR treatments.

METHODS

A retrospective cohort study of 37-45-year-old women undergoing preimplantation genetic testing for monogenic disease or structural chromosomal rearrangement cycles from 2010 to 2021 was conducted at a university hospital reproductive centre. The purpose was to develop a clinical predictive model for live birth in these women. The main outcome studied was the cumulative live birth rate in the first or subsequent cycles. Developing a decision tree enabled a comprehensive study of clinical parameters and expected outcomes.

RESULTS

The analysis included 158 women undergoing 753 preimplantation genetic testing cycles. The cumulative live birth rate was 37.342% (59/158). Decision tree analysis revealed that women aged ≤ 40.1 or women > 40.1 with one or more top-quality transferable embryos in their first cycle had the best chance for a live baby (56% and 41%, respectively). Those older than 40.1 without top-quality embryos and seven or fewer dominant follicles had no live births. A Kaplan-Meier curve showed that for autosomal dominant diseases, there was a negligible increase in live birth rate after three cycles, compared to six cycles in autosomal recessive inheritance.

CONCLUSION

In older women, the chance of delivering after repeated cycles is higher in those with at least one top-quality unaffected embryo in their first preimplantation genetic testing cycle. Additional preimplantation genetic testing cycles after three in carriers of an autosomal dominant disorder and six in those with an autosomal recessive disorder should be considered prudently.

New insights regarding origin of monosomy occurrence in early developing embryos as demonstrated in preimplantation genetic testing

Introduction

Analyses of miscarriage products indicate that the majority of aneuploidies in early developing embryos derive from errors occurring during maternal meiosis and the paternal contribution is less than 10%. Our aim was to assess the aneuploidy (mainly monosmies) frequencies at the earliest stages of embryo development, 3 days following fertilization during In vitro fertilization (IVF) treatments and to elucidate their parental origin. Later, we compared monosomies rates of day 3 to those of day 5 as demonstrated from Preimplantation Genetic Testing for Structural chromosomal Rearrangement (PGT-SR) results.

Methods

For a retrospective study, we collected data of 210 Preimplantation Genetic Testing for Monogenic Disorder (PGT-M) cycles performed between years 2008 and 2019.This study includes 2083 embryos, of 113 couples. It also included 432 embryos from 90 PGT-SR cycles of other 45 patients, carriers of balanced translocations. Defining the parental origin of aneuploidy in cleavage stage embryos was based on haplotypes analysis of at least six informative markers flanking the analyzed gene. For comprehensive chromosomal screening (CCS), chromosomal microarray (CMA) and next generation sequencing (NGS) was used.

Results

We inspected haplotype data of 40 genomic regions, flanking analyzed genes located on 9 different chromosomes.151 (7.2%) embryos presented numerical alterations in the tested chromosomes. We found similar paternal and maternal contribution to monosomy at cleavage stage. We demonstrated paternal origin in 51.5% of the monosomy, and maternal origin in 48.5% of the monosomies cases.

Conclusion

In our study, we found equal parental contribution to monosomies in cleavage-stage embryos. Comparison to CCS analyses of PGT-SR patients revealed a lower rate of monosomy per chromosome in embryos at day 5 of development. This is in contrast to the maternal dominancy described in studies of early miscarriage. Mitotic errors and paternal involvement in chemical pregnancies and IVF failure should be re-evaluated. Our results show monosomies are relatively common and may play a role in early development of ART embryos.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13039-022-00582-5.

Fertility preservation and PGT-M in women with familial adenomatous polyposis-associated desmoid tumours

RESEARCH QUESTION

Is ovarian stimulation and pregnancy in women with familial adenomatous polyposis (FAP)-associated desmoid tumours safe?

DESIGN

The study included women with FAP-associated desmoid tumours who underwent fertility treatments at the authors' tertiary medical centre between the years 2011 and 2021. Data were collected from the fertility unit's charts and from the oncological registries. The main outcome measures were the number of vitrified oocytes and embryos, and the number of live births in preimplantation genetic testing for monogenic/single gene defects (PGT-M) cycles.

RESULTS

Overall, 17 women were identified suitable for this study. A total of 117 mature oocytes were vitrified for fertility preservation and 106 embryos were submitted to PGT-M. One patient returned to claim her cryopreserved oocytes, and five patients who underwent PGT-M embryo transfer reported three live births. A statistically significant decrease in selected fertility cycle parameters was observed in one woman who co-administered sorafenib (a multikinase inhibitor) during her first cycles of treatment, as the mean number of oocytes before and after was 2.7 (±1.3) versus 13.2 (±3.3) (P = 0.02), the mean number of metaphase II oocytes was 2.2 (±2.1) versus 7.7 (±2.6) (P = 0.007), and the mean number of two-pronuclei oocytes was 0.5 (±1.1) versus 3.5 (±1.7) (P = 0.09). Three patients had a median desmoid tumour growth on magnetic resonance imaging of 6.2 (2.9-7.2) cm when compared with prior ovarian stimulation imaging.

CONCLUSIONS

Ovarian stimulation for women with desmoid tumours was characterized in some patients with an acceleration in tumour growth, regardless of the use of aromatase inhibitors. The use of sorafenib should be carefully considered during the course of fertility treatment.