Effect of the interval between onset of sustained fetal bradycardia and cesarean delivery on long-term neonatal neurologic prognosis

Objective

To examine the effect of the interval between onset of sustained fetal bradycardia and cesarean delivery on long-term neonatal neurologic prognosis.

Method

A retrospective observational case-series performed with patients who had sudden-onset and sustained (< 100 beats per minute) fetal bradycardia during labor. Fetal heart rate was monitored closely until cesarean delivery. The effect of the interval between the onset of bradycardia and delivery on neonatal neurologic prognosis was examined.

Results

Among 2267 deliveries in 2002-2003 at Kitasato University Hospital, 19 pregnancies met the inclusion criteria. Episodes of fetal bradycardia were due to umbilical cord prolapse (n = 5), placental abruption (n = 4), uterine rupture (n = 3), maternal respiratory failure (n = 1), and other causes (n = 6). Mean onset of fetal bradycardia to delivery interval (BDI) was 20.5 ± 8.9 minutes. Mean decision-to-cesarean delivery interval was 11.4 ± 3.9 minutes. BDI was negatively correlated with umbilical arterial pH at delivery. There were 3 postnatal deaths. Neurologic assessment at the age of 2 years revealed that 15 of 16 children were neurologically normal. When the BDI was less than 25 minutes, all term pregnancies led to normal neonatal neurologic development.

Conclusion

In the event of sustained intrapartum fetal bradycardia, delivery by emergency cesarean within 25 minutes improved long-term neonatal neurologic outcome.