RESUMO
BACKGROUND: The alpha-fetoprotein (AFP) is a glycoprotein, which is produced by the human fetus. Previous studies have shown associations between elevated AFP levels and an increased risk of adverse perinatal outcomes. OBJECTIVE: To determine if abnormal AFP levels are associated with adverse perinatal outcomes. The AFP concentrations were calculated as Multiples of the medians (MoM). PATIENTS AND METHOD: A prospective cohort study, including 283 pregnant women, the maternal serum concentration of AFP was determined between 15 and 20 weeks of pregnancy, and the pregnancy was followed until term, when we search for the perinatal outcomes. The study was made in the Instituto Nacional de Perinatología, in Mexico City, from August 2007 to January 2008. For the analyses, the AFP concentrations were calculated as Multiples of the medians (MoM). RESULTS: The threshold of 1.5 MoM increases the risk for preterm delivery (RR: 1.77, IC 95%: 1.04-3.03), abruption placentae (RR: 3.67, IC 95%: 1.59-8.49), placenta accreta (RR: 3.67, IC 95%: 1.59-8.49) and for intrauterine growth restriction (RR: 2.86, IC 95%: 1.74-4.68) There was a weak relation between AFP concentration and birth weight (r = -0.12, p = 0.047) and no correlation with pregnancy weeks at birth. CONCLUSIONS: There is a relation between adverse perinatal outcome and abnormal AFP levels. The evidence of an increase in the AFP concentration in fetuses without congenital defects should alert de clinician about the possibility of other adverse perinatal outcomes and those results must be included in the prenatal risk assessment.