A contraction stress test (CST) measures the fetus's ability to tolerate the stress of uterine contractions started (induced) before true labour begins.
Electronic fetal heart monitoring is done during a contraction stress test to evaluate the fetus's heart rate during contractions. The fetus's heart rate during contractions helps evaluate the placenta's ability to provide enough oxygen to the fetus.
A contraction stress test that shows the placenta is not supplying enough oxygen to the fetus will help the doctor determine the safest method of delivery.
A contraction stress test is also called an oxytocin challenge test.
Medical Review:Sarah A. Marshall, MD - Family Medicine & Donald Sproule, MDCM, CCFP - Family Medicine & Adam Husney, MD - Family Medicine & Kathleen Romito, MD - Family Medicine & Femi Olatunbosun, MB, FRCSC, FACOG - Obstetrics and Gynecology, Reproductive Endocrinology