Androgen insensitivity syndrome discovered due to discordance in prenatal assessments of fetal gender

In this case report, a pregnant woman chose non-invasive prenatal testing (NIPT) following a combined first-trimester screening showing a risk of trisomy 21 at 1:200. The NIPT was normal, and the sex of the fetus was predicted to be male. At 20 gestational weeks, an ultrasound examination predicted the fetus to be female. Because of these discordant results, an amniocentesis was offered but declined. The child was postnatally tested with a karyotype: 46,XY and found heterozygous for a pathogenic variant in the androgen receptor gene, which may cause partial or complete androgen insensitivity syndrome.