Fetal heart rate pattern and risk for respiratory disturbance in full-term newborns.

Etiologic and pathogenetic factors responsible for respiratory disturbances in full-term infants are still unclear. The authors' intention was to analyze to what extent fetal stress, expressed in terms of abnormal fetal heart rate pattern, was reflected in neonatal respiratory disturbance. The study was performed prospectively over one year and included 157 term infants. Contrary to general belief, there was a significantly lower incidence of respiratory disturbances after ominous fetal heart rate pattern, ie, basal bradycardia, late or severe variable decelerations, and reduced variability than after a normal fetal heart rate pattern. It is suggested that these results may be due to a favorable effect on the fetal lung of systemic or local factors, produced in response to intrauterine stress.