Objective: Conservative management of intrahepatic obstetric cholestasis is associated with a high stillbirth rate despite monitoring of fetal well-being with non-stress test and amniotic fluid volume assessment. Most cases of stillbirth are associated with meconium passage. We prospectively evaluated the effect of a management protocol inclusive of surveillance for presence of meconium and induction of labor at 37 weeks.
Study design: Between January 1989 and December 1997, all women with obstetric cholestasis underwent transcervical amnioscopy after 36 weeks for assessment of amniotic fluid color, in addition to standard monitoring of fetal well-being (semi-weekly non-stress test and amniotic fluid volume determinations). Amniocentesis for fetal lung maturity and amniotic fluid color assessment was performed before 36 weeks in severe cases. Labor was induced at 37 weeks or earlier in the presence of non-reassuring fetal testing, meconium, or severe maternal symptoms unresponsive to therapy with mature fetal lungs. The obstetric outcome of the group with cholestasis was compared with that of the general obstetric population at our Institution during the study period. The rate of fetal death in the study group was compared with that of series published within the last 20 years, which used expectancy and conventional monitoring of fetal well-being. Statistical analysis utilized Fisher's exact test, Chi-square, and Student's t-test with P value <0.05 or an odds ratio (OR) with 95% confidence interval (CI) not inclusive of the unity considered significant.
Results: Obstetric cholestasis was diagnosed in 206/20,815 pregnant women (1%) at a median gestational age of 34 weeks (range 20-40). Delivery was prompted by non-reassuring fetal testing in four cases (2%). Meconium passage was documented in 33 cases (16%), in 11 of which before onset of labor and in 10 before 37 weeks. The rate of meconium passage before 37 weeks (17.9 versus 2.9%, OR=7.3; 95% CI 3.3, 16.0) was significantly higher in obstetric cholestasis than in the general obstetric population, whereas the cesarean section rate was similar in the two groups (15.1 versus 16.0%, OR=0.9; 95% CI 0.6, 1.4). The fetal death rate was significantly lower in the group managed with the current strategy than in the published series of obstetric cholestasis (0/218 versus 14/888, P=0.045).
Conclusion: In pregnancies complicated by obstetric cholestasis, a protocol inclusive of search for meconium and elective delivery at 37 weeks, in addition to standard monitoring of fetal well-being, can significantly reduce the stillbirth rate without increasing the cesarean delivery rate.