PAPPA and polycystic ovary syndrome: In conclusion, there was a significant difference in free β-HCG, inhibin-A, AFP level, and the risks of pre-eclampsia and trisomy 18 in PCOS and healthy women; however, no significant difference was observed in other aneuploidies, SLOS risk, NT, PAPP-A, HCG, and UE3 between the two groups.