Is First Trimester Maternal Serum Alpha Fetoprotein Predictive of Adverse Pregnancy Outcomes? [30L]

INTRODUCTION: While elevated second trimester maternal serum alpha fetoprotein (msAFP) has been associated with adverse pregnancy outcomes, the utility of first trimester msAFP (AFP1) in predicting these outcomes is not known. Our objective was to determine the association between AFP1 and ischemic placental disease (a composite of preeclampsia, fetal growth restriction and/or placental abruption). Secondary outcomes included correlation with second trimester msAFP (AFP2), in addition to the association of AFP1 with preterm birth, fetal demise, and spontaneous abortion. METHODS: An IRB-approved multi-site retrospective cohort study was performed including all patients with AFP1 as part of routine first trimester aneuploidy screening over from April 2015-August 2016. Pregnancies with multiple gestations and known structural or chromosomal abnormalities were excluded. Delivery records were reviewed for adverse pregnancy outcomes. Spearman correlation coefficient assessed the relationship between AFP1 and AFP2. Fisher exact test and Odds Ratios were used to determine the association between AFP1 and adverse pregnancy outcomes. RESULTS: Of 968 patients with AFP1, 847 had complete records available for review (87.5%). There was a positive correlation between AFP1 and AFP2 (rho =0.57, P<.001). There was a significant association between elevated AFP1 (> 2.0 MoM) and ischemic placental disease, 18.9% vs 8.2% (OR 2.6, 95% CI 1.4-4.9). Additionally, there was a significant association between high AFP1 and early onset preeclampsia <34 weeks, spontaneous preterm birth and overall preterm birth. CONCLUSION: Elevated first trimester msAFP is associated with ischemic placental disease and preterm birth and may help to identify at risk pregnancies as early as the first trimester of pregnancy.