A survey of pregnancies complicated by decreased amniotic fluid.

Four hundred seventy-one patients undergoing diagnostic ultrasonography were identified as having moderately decreased amniotic fluid or oligohydramnios, and 339 of these cases were reviewed. Ninety-two of the patients were excluded from further statistical analysis because their decreased fluid was attributed to rupture of the membranes only. Of the remaining patients there was a 7% neonatal malformation rate. Decreased amniotic fluid before 27 weeks of gestation was associated with a significantly poor outcome. Of all the live births, infants of patients with oligohydramnios had lower Apgar scores at 1 minute and 5 minutes than did infants of patients with moderately decreased amniotic fluid. Of cases of patients with decreased fluid, 10% involved fetal distress during labor and in 17% meconium was present. Decreased levels of fluid were associated with an increased rate of abdominal deliveries. Preeclampsia was present in 24.7% of patients with decreased fluid. There was no correlation between the quantitative fluid amounts and the severity of the disease. In view of normative data and clinical experience, these observations suggest that the diagnosis of decreased amniotic fluid on routine ultrasonography requires a fetal scan to rule out anomalies, close antepartum observation to detect complications that may arise in the pregnancy, and delivery under conditions that allow appropriate support and intervention on behalf of the fetus.