[Factors associated with fetal brain-sparing effect in patients with hypertension in pregnancy]

To determine perinatal outcomes and factors associated with fetal brain sparing effect diagnosed by Doppler flow velocimetry in patients with arterial hypertension.

We performed a cross-sectional retrospective study including 129 pregnant women with arterial hypertension and submitted to Doppler flow velocimetry, within fifteen days before delivery. Women with multiple pregnancies, fetal malformations, genital bleeding, placenta praevia, premature rupture of membranes, smoking, illicit drug use and chronic diseases were excluded. We analyzed the biological, socio-demographic and obstetric characteristics, as well the perinatal outcomes. To determine the association between variables, we used the χ² test, Fisher's exact test and Student's t-test. Multiple logistic regression analysis was performed to determine the factors associated with fetal centralization.

Pre-eclampsia was the most frequent hypertensive disorder (53.5%) and fetal brain sparing effect was observed in 24.0% of fetuses. The prenatal factors associated with fetal brain sparing were the persistence of bilateral protodiastolic notches in uterine arteries (OR 3.6; 95%CI 1.4 - 9.4; p=0.009) and intrauterine growth restriction (IUGR) (OR 3.3; 95%CI 1.2 - 9.3; p=0.02). The perinatal outcomes associated with fetal brain sparing were gestational age <32 weeks, small for gestational age (SGA) infants, birth weight <2,500 g and perinatal death. There was no association with other maternal or neonatal variables.

The main factors associated with fetal brain sparing were persistence of uterine arteries notches, IUGR, and increased frequency of adverse perinatal outcomes.