RESUMO
PURPOSE: To determine maternal and perinatal outcomes in pregnant women with low amniotic fluid, according to the amniotic fluid index (AFI). METHODS: A cohort study conducted on 176 patients admitted to the high risk ward of Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), in Recife, Pernambuco, Brazil. Amniotic fluid was measured by the amniotic fluid index, and classified as low when between 5.1 and 7.9 cm, moderate oligohydramnios between 3.1 and 5.0 cm, and severe oligohydramnios when less than or equal to 3.0 cm. To determine the difference between the three groups of categorical variables studied the chi-square and Fisher exact tests were used, when applicable, and for the numerical variables the Mann-Whitney test was applied, with the level of significance set at 5%. RESULTS: Fetal malformation more frequently occurred when oligohydramnios was severe. Hypertensive disorders, however, were associated with moderate oligohydramnios. There was similarity between the three groups in relation to premature rupture of membranes and other causes. Low amniotic fluid was more frequently diagnosed when tested at the gestational age of 32 weeks or earlier. Regarding the perinatal outcomes, the incidence of Apgar score <7 in the 1st and 5th minutes, perinatal death, neonatal jaundice and pulmonary hypoplasia was higher when oligohydramnios was moderate to severe. CONCLUSIONS: Maternal and perinatal causes and outcomes in pregnant women with low amniotic fluid vary with respect to their AFI, severe oligohydramnios being associated with fetal malformation and other adverse perinatal outcomes.