Utility of Maternal Serum Analyte Screening in the Era of Cell-free Fetal DNA

Background: To determine whether in the era of cell-free fetal DNA (cffDNA), first and second trimester maternal serum analytes will be obsolete or whether they have a role in predicting adverse pregnancy outcomes. Methods: Retrospective cohort study using maternal serum analyte results from first trimester and sequential screening tests from 1/2002 to 12/2012. Abnormal serum analytes included low pregnancyassociated plasma protein-A (PAPP-A), defined as ≤ 0.4 multiples of the median (MoM), and elevated alpha fetal protein (AFP), defined as ≥2.5 MoM. Patients were assigned into 4 groups; both low PAPP-A and elevated AFP (BOTH), an isolated elevated AFP (AFP), an isolated low PAPP-A (PAPPA), and those with normal results (NML). Results: 328 patients with abnormal analytes were matched 2:1 to patients with normal analytes, leaving 984 included. Compared to the other groups, the BOTH group (N=5) delivered earlier, had lower birth weights, and had a higher incidence of preterm birth and growth restriction. The AFP group (N=70) had the highest percentage of miscarriage <20 weeks. The PAPP-A group (N=254) conferred an increased risk of gestational hypertension/preeclampsia. Conclusions: The importance of maternal serum analytes and their link to poor pregnancy outcomes should not be forgotten in the era of cffDNA.