TRANSABDOMINAL AMNIOINFUSION IN OLIGOHYDRAMNIOS AT TERM BEFORE INDUCTION OF LABOR WITH INTACT MEMBRANES - A RANDOMIZED CLINICAL-TRIAL

OBJECTIVE: Our purpose was to determine the effectiveness of transabdo minal amnioinfusion before induction of labor in reducing the incidenc e of fetal distress in pregnancies with oligohydramnios at term. STUDY DESIGN: Between June 1991 and September 1994 primiparous women with u ltrasonographic evidence of oligohydramnios at term, intact membranes, and unripe cervix (Bishop score less than or equal to 6), candidates for induction of labor with cervical or vaginal prostaglandin E(2) gel , were randomly selected to receive transabdominal amnioinfusion (amni oinfused group, n = 39) or to proceed with direct labor induction (con trol group, n = 40). Inclusion criteria were (1) singleton gestation, (2) vertex presentation, (3) ultrasonographic estimation of fetal weig ht greater than or equal to 2500 gm, and (4) reactive nonstress test. Fetoneonatal outcome variables were compared between the two groups. S tatistical analysis used contingency tables, Student t test, or Wilcox on rank-sum tests, where applicable. RESULTS: Amnioinfusion was succes sfully performed in 100% of the patients randomized for the procedure. The incidence of severely abnormal fetal heart rate tracings was sign ificantly higher in the control than in the amnioinfused group (42% [1 7/33] vs 5% [2/37], relative risk 12.9, 95% confidence interval 2.4 to 56.4). The rate of cesarean sections performed for fetal distress was fivefold higher in the control group (25% [10/40] vs 5% [2/39], relat ive risk 4.9, 95% confidence interval 1.1 to 32.4). No bleeding compli cations or fetomaternal infectious morbidity were noticed. CONCLUSION: Transabdominal amnioinfusion is a safe, effective option for the prev ention of fetal distress in pregnancies with oligohydramnios at term w ith intact membranes and unripe cervix.