Is the fetal brain-sparing effect a risk factor for the development of intraventricular hemorrhage in the preterm infant

The intrauterine identification of fetuses at risk of developing intraventricular hemorrhage would be helpful to the perinatologist, in light of the recent results which suggest that indomethacin given to the infant reduces the risk of developing intraventricular hemorrhage. We hypothesized that fetuses undergoing brain sparing, as identified by a lowered pulsatility index (PI) in the middle cerebral artery, and delivered prior to 34 weeks may differ in terms of being at risk for intraventricular hemorrhage from those fetuses without the brain-sparing effect. The middle cerebral artery PI was studied in 43 fetuses between 25 and 33.6 weeks' gestation. The pregnancies were complicated by pre-eclampsia, intrauterine growth restriction (IUGR) and preterm labor. A cranial sonogram was performed during the first postnatal week in all the neonates. Intraventricular hemorrhage was present in 6/22 infants with a normal middle cerebral artery PI (group A) and 0/21 with an abnormal middle cerebral artery PI (group B) (p < 0.05). The mothers of the six fetuses who developed intraventricular hemorrhage underwent preterm labor. IUGR fetuses and pre-eclampsia were more common in group B. No difference was found between the two groups when the following variables were compared: (1) gestational age at the time of the Doppler study; (2) gestational age at delivery; (3) antenatal exposure to steroids; (4) antenatal exposure to magnesium; (5) Apgar score greater than 6 at 5 min; (6) respiratory distress syndrome in the newborn; (7) necrotizing enterocolitis; (8) Cesarean section; and (9) sepsis in the infant. Although the mean birth weight was significantly lower in group B than group A, no fetus in this group developed intraventricular hemorrhage. The fetal brain-sparing effect, pre-eclampsia and IUGR were associated with a lower risk of neonatal intraventricular hemorrhage than was preterm labor. Preterm labor appears to be a key factor in the development of intraventricular hemorrhage and must be included when testing associations with intraventricular hemorrhage.