The role of ultrasound assessment of amniotic fluid volume in the management of the postdate pregnancy.

Antepartum assessments of amniotic fluid volumes and their relationship to nonstress test patterns and pregnancy outcomes were retrospectively analyzed in 234 postdate pregnancies. The incidence of clinical oligohydramnios and a nonstress test revealing fetal heart rate deceleration or bradycardia was found to increase as the sonographic estimates of the amniotic fluid volume decreased. Furthermore, the postdate pregnancy with sonographic evidence of an adequate amniotic fluid volume had a significantly better perinatal outcome than the pregnancy without an adequate fluid volume. These results suggest that the postdate pregnancy with evidence of reduced amniotic fluid volume should be considered for a trial of labor with continuous electronic fetal monitoring.