Maternal serum alpha-1 antitrypsin levels in spontaneous preterm and term pregnancies

Currently, there are no accurate means to predict spontaneous preterm birth (SPTB). Recently, we observed low expression of alpha-1 antitrypsin (AAT) in SPTB placentas. Present aim was to compare the concentrations of maternal serum AAT in pregnancies with preterm and term deliveries. Serum C-reactive protein (CRP) was used as a reference inflammatory marker. Two populations were studied. The first population comprised women who eventually gave birth spontaneously preterm (SPTB group) or term (control group). The second population included pregnant women shortly before delivery and nonpregnant women. We observed that serum AAT levels were higher in the SPTB group than in the controls, and a similar difference was observed when serum CRP was considered in multivariable analysis. However, the overlap in the AAT concentrations was considerable. No statistical significance was observed in serum AAT levels between preterm and term pregnancies at delivery. However, AAT levels were higher at delivery compared to nonpregnant controls. We did not observe a strong correlation between serum AAT and CRP in early pregnancy samples and at labor. We propose that during early pregnancy, complicated by subsequent SPTB, modest elevation of serum AAT associates with SPTB.