918 The impact of preimplantation genetic testing for aneuploidy on prenatal screening

Abstract

The clinical utility of preimplantation genetic testing for aneuploidy (PGT-A) is well established. However, data is limited on the residual risk for abnormal prenatal screening in PGT-A screened embryos. We investigated whether PGT-A is associated with a reduced risk of abnormal prenatal screening in singleton pregnancies conceived using in vitro fertilization (IVF). Retrospective cohort of singleton IVF pregnancies conceived from a single center from 01/2014 to 09/2019. Exclusion criteria included transfer of mosaic embryos, vanishing twins, and missing data. Two cases of prenatally diagnosed aneuploidy that resulted in early voluntary terminations were also excluded. Maternal age was adjusted for donor egg age where indicated. The primary outcome of abnormal first or second trimester serum screening was compared between two groups: pregnancy after transfer of a euploid embryo by PGT-A (n = 208) versus transfer of an untested embryo (n = 211). Secondary outcomes included other prenatal screening modalities and rate of invasive prenatal diagnostic testing. Multivariate backwards-stepwise logistic regression with Firth method was used to adjust for potential confounders. Baseline characteristics compared between the two groups are displayed in Table 1. PGT-A was not associated with a reduced risk of abnormal first-trimester (adjusted OR 1.64, 95% CI 0.82-3.39) or second-trimester screening (adjusted OR 0.96, 95% CI 0.56-1.64) (Table 2). The likelihood of cell free DNA testing, soft sonographic markers, major fetal structural malformations, genetic counseling and invasive prenatal diagnostic testing were also similar between the two groups (Table 2). Our data illustrate that PGT-A is not associated with a reduced rate of abnormal prenatal screening, or likelihood of invasive prenatal diagnostic testing. Nevertheless, counseling this patient population regarding the importance of prenatal screening and prenatal diagnostic testing where appropriate remains essential.View Large Image Figure ViewerDownload Hi-res image Download (PPT)