Prenatal management of the fetus with lethal malformation: from a study of oligohydramnios sequence.

47 cases of oligohydramnios sequence (OS) diagnosed at Kanagawa Children's Medical Center from 1992 to 2008 were studied retrospectively. Early termination of pregnancy was chosen in 9 cases, observed natural labor was chosen in 23 cases, and 18 cases resulted in natural deliveries. Fetal demise occurred during labor in 44.4% of terminated cases, while it occurred in 5.6% of observed cases. Preterm labors and breech presentations occurred most frequently. Most infants died within 18 hours after their births. There were 3 familial cases. These results provide important information for planning the perinatal care when fetuses are diagnosed with OS.