Prenatal screening after preimplantation genetic testing for aneuploidy: time to evaluate old strategies

Abstract

Research question

What is the performance of the first-trimester aneuploidy screening in pregnancies achieved after in vitro fertilization (IVF) and preimplantation genetic testing for aneuploidy (PGT-A) transferred embryos in our medical setting?

Design

Retrospective cohort study in a single tertiary care centre between January 2013 and June 2022. A total of 20,237 women have had a prenatal follow-ups in our clinical centre and were included in our study. Three groups were included: singleton pregnancies conceived after the transfer of a PGT-A screened euploid-embryo (n=511), singleton pregnancies conceived after IVF without PGT-A (n= 3,291), and singleton naturally conceived pregnancies (n= 16,436).

Results

The conventional combined test for PGT-A pregnancies had a specificity of 91% and the sensitivity could not be calculated since there were no cases of fetal aneuploidy in this group. In 89.1% of pregnancies conceived after IVF with PGT-A with a high-risk for T21, 18, or 13, the result was related to advanced maternal age.

Conclusions

The current screening strategy for T21, T18, and T13 can generate unnecessary tests in pregnancies achieved by IVF-PGT-A. A new protocol is needed for these patients with a greater weight on ultrasound markers.