Clinical experience with the contraction stress test.

During a period of 16 months, 1 170 contraction stress tests (CST) were performed on 767 women who were at high risk of losing their babies. The tests were positive in 42 patients, of whom 29 were subsequently delivered by caesarean section. Fetal distress, which necessitated caesarean section, occurred in 5 of 6 cases of intra-uterine growth retardation in which labour was induced. Abruptio placentae caused the intra-uterine death of 4 fetuses, 3 of which died within 7 days of a negative CST. The low perinatal mortality rate of 13 demonstrates the reliability of the CST in the evaluation of placental function in obstetric patients who are at high risk.