The Influence of Electronic Fetal
Monitoring on Perinatal Morbidity
Kirk A. Keegan, Jr., M.D.
Edward J. Quilligan, M.D.,
Feizal Waffarn, M.D.
The past ten to twelve years have seen tremendous advances made in reducing perinatal morbidity and mortality, with mortality rates falling from 29.7 in 1,000 births in 1970 to 18.2 in 1,000 in 1979. Concomitant with this decline has been a literal explosion of technologic advancements—amniocentesis, L/S ratio, ultrasound imaging, respirator care, and neonatal and fetal-heart-rate (FHR) monitoring, to name only a few. Introduction of FHR monitoring in the late 1960s and its widespread clinical acceptance by the mid 1970s has led some authors to attribute much of the decline in neonatal morbidity and mortality to its use (Krebs et al., 1980; Parer, 1981; Paul and Hon, 1974). Others, however, have argued this point, claiming FHR monitoring to be meddlesome, of no benefit, to impact unfavorably on cost analysis, and to increase Caesarean section (C/S) rates (Haverkamp, et al., 1979; Neutra et al., 1978). Confounding the evaluation of the potential benefits of FHR monitoring have been changing philosophies in obstetrical and neonatal care, such as more frequent C/S for breech and the very low birthweight infant, aggressive management of dysfunctional labor, newborn resuscitation, and neonatal intensive care, all of which have been shown to affect favorably neonatal morbidity and mortality statistics, perhaps independently of monitoring. While a direct cause-and-effect association between FHR monitoring and improved perinatal outcome may be difficult to demonstrate, clear relationships exist between the status of fetal and neonatal hypoxemia, acidemia, and both short- and long-term neonatal outcome. Normal oxygenation and metabolic status, in the absence of other predisposing conditions, rarely results in sequelae. However, the presence of hypoxemia and acidosis in the neonate has been correlated with low Apgar score, increased incidence of Respiratory Distress Syndrome (RDS), enterocolitis, encephalopathy, seizure activity, long-term neurologic handicap, and death (Garite, personal communication; Holden, 1982; Martin et al., 1974; Meyers, 1973).
Any technique that could provide information on fetal oxygenation and metabolic status could potentially alter, through some form of