Pregnant women diagnosed with PCOS, after the ovulation induction with letrozole or clomiphene (but non-IVF procedure) and a high AMH concentration in the first trimester (especially > 9.3 ng/mL), are at risk of preterm labor in the third trimester as compared to the group of women who underwent the induction of the ovulation but PCOS was not recognized (156, 157) (Figure 5). This evidence concerns the gene AMH and polycystic ovary syndrome.