Abnormal second-trimester serum analytes are more predictive of preterm preeclampsia

OBJECTIVE: We sought to determine the association of abnormal second-trimester serum analytes with early preterm preeclampsia. STUDY DESIGN: We conducted a retrospective study of 7767 subjects undergoing second-trimester serum aneuploidy screening. Values of maternal serum alpha-fetoprotein (AFP), beta-human chorionic gonadotropin (hCG), and inhibin (INH) were calculated as multiples of the median (MoM) and evaluated by gestational age at delivery and occurrence of preeclampsia. RESULTS: Of 459 (6.5%) cases of preeclampsia, 65 (14%) delivered <34 weeks and 394 (86%) delivered >34 weeks. Elevated AFP, hCG, and INH >2 MoM were associated with preeclampsia, and the odds ratio was higher for the development of preeclampsia <34 weeks than >34 weeks (odds ratio, 8.04 vs 2.91 for AFP, 3.6 vs 2 for hCG, and 4.17 vs 3.08 for INH, P < .001 for all). The higher the MoM for each analyte the greater the likelihood of preeclampsia. CONCLUSION: Elevated AFP, hCG, and INH levels >2 MoM are associated with developing early preeclampsia, and the more elevated they are, the higher the likelihood.