Marked variability in intrapartum electronic fetal heart rate patterns: association with neonatal morbidity and abnormal arterial cord gas.

OBJECTIVE

Investigate marked variability in fetal heart rate (FHR) patterns before delivery and its association with neonatal morbidity and abnormal arterial cord gases.

STUDY

DESIGN

Prospective cohort of laboring patients at term. Composite neonatal morbidity (respiratory distress, mechanical ventilation, suspected sepsis, meconium aspiration syndrome, therapeutic hypothermia, hypoxic-ischemic encephalopathy, seizure, and death) and abnormal arterial cord gases (pH < 7.10, lactate ≥ 4 mmol/L, base deficit < -12 mEq/L) were assessed with multivariable logistic regression.

RESULT: Three hundred and ninety (4.5%) neonates had marked variability in FHR patterns before delivery. There was no difference in composite neonatal morbidity (aRR 1.22; 95% CI 0.91-1.63), though neonates with marked variability in FHR patterns were more likely to have a respiratory distress (aRR 1.85; 95% CI 1.25-2.70). There was an increased risk of composite abnormal arterial cord gases (aRR 1.66; 95% CI 1.47-1.88).

CONCLUSION

Marked variability in FHR patterns was not associated with composite neonatal morbidity but was associated with abnormal arterial cord gases.