Fetal heart rate patterns and neurodevelopmental outcome in very low birth weight infants

To evaluate the validity of fetal heart rate monitoring during the last hour prior to birth, as a predictor of long term neurodevelopmental outcome of very low birth weight infants.

A total of 111 very low birth weight infants were included in the study. Fetal heart rate tracings were obtained during the last hour prior to delivery. A perinatologist, blinded to the neonatal outcome, evaluated the tracings and divided them into three groups: reassuring, nonreassuring, and pathological. Neurodevelopmental status was evaluated at age 2 years. The relationship between fetal heart rate monitoring results and the neurodevelopmental outcome at 2 years of age was assessed with a chi-square test and the Student's t-test.

At 2 years of age 97 (87.4%) of the children had normal neurodevelopmental function, while 14 (12.6%) had variable degrees of neurodevelopmental impairment. The fetal heart rate monitoring results were classified as reassuring (normal) in 35 cases (31.5%), nonreassuring in 56 cases (50.5%), and pathological in 20 cases (18.0%). Both normal and pathological fetal heart rate patterns were associated with similar incidence of abnormal neurodevelopmental outcome, 14.3% and 15.0% of cases, respectively (p=0.778). Pathological fetal heart rate patterns as a predictor of neurodevelopmental outcome had a sensitivity of 27%, specificity of 74%, positive predictive value of 15%, and negative predictive value of 86%.

Electronic fetal heart rate monitoring prior to delivery is not a reliable tool for the prediction of neurodevelopmental impairment in premature infants of very low birth weight, at 2 years of age.