The relationship between electronic fetal monitoring and Apgar score

A study was made of the relationship between electronic fetal heart monitoring and the Apgar score in 14,350 babies delivered between 1970 and 1975 at Beth Israel Hospital, Boston. Simple comparison of Apgar scores in monitored and unmonitored babies showed no difference at 5 minutes. When we controlled for gestational age and other potential confounders, a different pattern emerged. In a group of obviously high-risk pregnancies, monitored babies had a more favorable distribution of 5-minute Apgar scores (3.8% instead of 7.2% with a score below 6, P = 0.020). This group contained the 7.4% of all babies who were greater than or equal to 36 weeks of gestational age at highest risk (with problems such as hydramnios, multiple pregnancy, placental complication, or malpresentation). A similar trend for babies less than 36 weeks' gestational age with the same obstetric complications did not achieve statistical significance. There was no evidence for benefit in the other risk categories.