Abnormal Doppler velocimetry is related to adverse perinatal outcome for borderline amniotic fluid index during third trimester.

AIM: To evaluate the relationship between abnormal Doppler velocimetry and adverse perinatal outcomes in pregnancies with borderline amniotic fluid index (AFI).

METHODS: Medical records of 3740 pregnancies with known AFI and Doppler velocimetry measurements within 2 weeks of delivery, and delivered between January 1996 and December 2003, were retrospectively analyzed. Borderline AFI was defined as 5 cm < AFI < or = 8 cm. For the umbilical artery, Doppler velocimetry was considered abnormal when the S/D ratio was greater than 3.0 or when end-diastolic flow was absent; whereas, for the uterine artery, the S/D ratio was greater than 2.6 or presence of end-systolic notch was defined as abnormal. Adverse perinatal outcomes (small for gestational age, cesarean section for fetal distress, 5 min Apgar score of less than 7, respiratory distress syndrome, NICU admission, and perinatal death) according to Doppler velocimetry in borderline AFI were evaluated.

RESULTS: Compared to the normal AFI group (n = 3523), the borderline AFI group (n = 217) had significantly higher incidence of adverse perinatal outcome (28.8% vs 54.8%). There was 3-fold increase in the incidence of adverse perinatal outcome among women with the borderline AFI in comparison to normal AFI (OR, 3.00; CI, 2.27-4.00). When abnormal Doppler velocimetry was associated with borderline AFI, a 5-fold increase in the incidence of adverse perinatal outcome was noted (OR, 5.26; CI, 3.00-9.21).

CONCLUSION: In the borderline AFI group, the presence of abnormal Doppler velocimetry measurement was related to increased risk of adverse perinatal outcome. Thus, borderline AFI of 5-8 cm, especially when associated with abnormal Doppler velocimetry, mandates closer antenatal surveillance.