Clinical Application of Noninvasive Prenatal Testing in Singleton Pregnancy with and without in vitro Fertilization: A 6-year Observational Study at a Single Tertiary Center.

Background: Studies on the use of noninvasive prenatal testing (NIPT) in pregnancies conceived by in vitro fertilization (IVF) remain inadequate. This study aimed to evaluate the performance of NIPT in singleton pregnancies conceived by IVF and to compare it with that in naturally conceived (NC) pregnancies.

Methods: A retrospective analysis was performed on 86397 pregnancies (IVF=3723, NC=82674). The performance of NIPT was assessed by calculating the sensitivity, specificity, and positive predictive value (PPV).

Results: The failure rate in the IVF group was significantly higher than that in the NC group (0.16% vs 0.04%, p < 0.05). Among the 3717 cases successfully tested in the IVF group, the sensitivities of trisomy (T) 21 and sex chromosome aneuploidy (SCA) were both 100%, with specificities of 99.92% and 99.76%, respectively. The PPVs of T21 and SCA were both 50%. Of the 82630 cases successfully tested in the NC group, all corresponding sensitivities and specificities were greater than 98%. The PPVs of T21, T18, T13, SCA and rare autosomal aneuploidies were 70.86%, 41.67%, 20.51%, 39.90%, and 7.65%, respectively. Furthermore, although the median fetal fractions (FFs) in the IVF group were significantly lower than that in the NC group (11.23% vs 12.05%, p < 0.001), the kinetics of FFs during gestation demonstrated a very similar trend between these two groups.

Conclusion: Our findings suggest that NIPT is a valid technique for detecting fetal chromosomal aneuploidies in IVF singleton pregnancies.