Amniotic fluid index as a predictor of adverse perinatal outcome in the HELLP syndrome.

OBJECTIVE: To evaluate the prognostic value of an amniotic fluid index (AFI) < or = 5 cm for an adverse perinatal outcome in pregnancies with the syndrome of hemolysis, elevated liver enzymes and low platelets (HELLP syndrome).

STUDY DESIGN: A prospective, observational study of patients with the HELLP syndrome. An ultrasound estimate of amniotic fluid volume was obtained on admission. Adverse intrapartum outcomes included amnioinfusion for variable decelerations and/or indicated abdominal/vaginal operative delivery for nonreassuring fetal heart rate changes. Maternal characteristics and perinatal outcome parameters were compared AFI < or = vs. > 5 cm. Statistical analysis was performed using chi2 analysis, Student's t test and receiver-operator characteristic curve (ROC) analysis.

RESULTS: Between January 1996 and February 1999, 120 patients were enrolled. Twenty-six (22%) had an AFI < or = 5 cm. This group did not differ from that with AFI > 5 cm regarding the severity of the HELLP syndrome, admission-to-delivery interval (p = 0.354), variable decelerations in labor (p = 0.06), Apgar score of < 7 at 5 minutes (p = 0.361), cesarean delivery for nonreassuring fetal status (p = 1.0) or significant fetal acidosis (pH < 7.0 [p = 0.2101). ROC analysis revealed no AFI measurement between 0 and 16 cm that was useful for identifying the compromised fetus.

CONCLUSION: Antepartum/intrapartum performance of AFI in patients with the HELLP syndrome is a poor prognostic test for subsequent fetal compromise.