Fetal brain Doppler to predict cesarean delivery for nonreassuring fetal status in term small-for-gestational-age fetuses.

OBJECTIVE

To estimate the value of fetal brain Doppler in predicting the risk of cesarean delivery for nonreassuring fetal status and neonatal acidosis after labor induction in small-for-gestational-age fetuses with normal umbilical artery Doppler.

METHODS

Fetal brain Doppler parameters, including cerebral tissue perfusion measured by fractional moving blood volume, cerebroplacental ratio, and middle cerebral artery pulsatility index, were evaluated before labor induction in a cohort of 210 term small-for-gestational-age fetuses with normal umbilical artery Doppler and 210 control participants matched by gestational age. The value of the cerebral Doppler indices to predict the risk of cesarean delivery, cesarean delivery for nonreassuring fetal status, and neonatal acidosis was analyzed.

RESULTS

Overall, small-for-gestational-age fetuses showed a significant higher incidence of cesarean delivery (37.6% compared with 19.5%, P<.001), cesarean delivery for nonreassuring fetal status (29% compared with 4.8%, P<.001), and neonatal acidosis (7.6% compared with 2.4%, P=.03) than control participants. Within the small-for-gestational-age group, middle cerebral artery vasodilation was associated with the highest risk of cesarean delivery (67.7% compared with 32.4%, P<.001) and cesarean delivery for nonreassuring fetal status (58.1% compared with 24%, P<.001). In the subgroup of normal middle cerebral artery, incorporation of cerebroplacental ratio further distinguished two groups with different risks of cesarean delivery (51.4% compared with 27.5%, P<.01) and cesarean delivery for nonreassuring fetal status (37.8% compared with 20.4%, P=.01). Middle cerebral artery vasodilation was associated with increased risk of neonatal acidosis (odds ratio, 9.0). Fractional moving blood volume was not associated with the risk of cesarean delivery for nonreassuring fetal status or neonatal acidosis.

CONCLUSION

Evaluation of brain Doppler indices before labor induction discriminates small-for-gestational-age fetuses at high risk of cesarean delivery for nonreassuring fetal status and neonatal acidosis.