[Changes of blood flow in the umbilical artery in hypertensive pregnancy and the implications in the neonatal outcomes].

PURPOSE To evaluate the anthropometric characteristics of morbidity and mortality of premature newborns (NB) of hypertensive mothers according to the presence or absence of flow (DZ) or reverse (DR) diastolic flow in the dopplervelocimetry of the umbilical artery. METHODS A prospective study was conducted on preterm newborns of pregnant women with hypertension between 25 and 33 weeks of gestational age, submitted to umbilical artery Doppler study during the five days before delivery. Delivery occurred at Hospital Regional da Asa Sul, Brasília - Federal District, between November 1st, 2009 and October 31st, 2010. The infants were stratified into two groups according to the results of Doppler velocimetry: Gdz/dr=absent end-diastolic velocity waveform or reversed end-diastolic velocity waveform, and Gn=normal Doppler velocimetry. Anthropometric measurements at birth, neonatal morbidity, and mortality were compared between the two groups. RESULTS We studied 92 infants, as follows: Gdz/dr=52 infants and Gn=40 infants. In Gdz/dr, the incidence of infants small for gestational age was significantly greater, with a relative risk of 2.5 (95%CI 1.7 - 3.7). In Gdz/dr, infants remained on mechanical ventilation for a longer time: median 2 (0‒28) and Gn median 0.5 (0‒25) p=0.03. The need for oxygen at 28 days was higher in G dz/dr comparing to Gn (33 versus 10%; p=0.01). Neonatal mortality was higher in Gdz/dr compared to Gn (36 versus 10%; p=0.03; relative risk of 1.6; 95%CI 1.2‒2.2). Logistic regression showed that, with each 100 grams lower birth weight, the chance of death increased 6.7 times in G dz/dr (95%CI 2.0 - 11.3; p<0.01). CONCLUSION In preterm infants of mothers with hypertensive changes in Doppler velocimetry of the umbilical artery, intrauterine growth restriction and neonatal prognosis are often worse, with a high risk of death related to birth weight.