Electronic fetal monitoring patterns associated with respiratory morbidity in term neonates

The purpose of this study was to identify electronic fetal monitoring patterns that are associated with neonatal respiratory morbidity.

In an on-going prospective cohort study of >8000 consecutive term, vertex, nonanomalous singleton pregnancies during labor, we performed this analysis within the first 5000 women as a representative sample. Electronic fetal monitoring patterns in the 30 minutes preceding delivery were extracted by trained obstetrics research nurses, who were blinded to clinical data, using the National Institute of Child Health and Human Development system; the data were compared between those with respiratory morbidity and healthy infants (no morbidities). The primary outcome was neonatal respiratory morbidity, which was defined as either oxygen requirement at ≥6 hours of life or any mechanical ventilation in the first 24 hours. Multivariable logistic regression was used to adjust for confounders.

Of 4736 neonates, 175 (3.4%) experienced respiratory morbidity. Most electronic fetal monitoring patterns were category II (96.6%; n = 4575). Baseline tachycardia (adjusted odds ratio [aOR], 2.9; 95% confidence interval [CI], 1.9-4.4), marked variability (aOR, 2.7; 95% CI, 1.5-5.0), and prolonged decelerations (aOR,2.7; 95% CI, 1.5-5.0) were significantly associated with an increased likelihood of term neonatal respiratory morbidity. Accelerations and persistent moderate variability were both significantly associated with a decreased likelihood of respiratory morbidity.

Specific features of category II electronic fetal monitoring patterns make respiratory morbidity more likely in nonanomalous term infants. Tachycardia, marked variability, or prolonged decelerations before delivery can assist providers in anticipating the potential need for neonatal respiratory support.