Maternal Body Mass Index influences Umbilical Artery Doppler Velocimetry in physiologic pregnancies.

OBJECTIVES: The aim of our study was to assess whether there is a relationship between maternal body mass index (BMI) and umbilical artery Doppler velocimetry in physiologic pregnancies. METHODS: Healthy pregnancy women, referred to our center at or before 32 weeks of gestation, were recruited. According to BMI, they were divided into underweight (BMI < 18.5), normal weight (BMI 18.5-24.9), overweight (BMI 25.0-29.9) and obese women (BMI ≥ 30). At 32(+0)  weeks of gestation, maternal BMI and umbilical artery Doppler velocimetry were recorded. A correlation between pulsatility index of umbilical artery and BMI was assessed by one-way ANOVA test, multiple comparison test (Bonferroni correction) and polynomial regression. RESULTS: One hundred eighty-five women were included. Mean pulsatility index of umbilical artery at 32(+0) was significantly higher in obese women (0.95 ± 0.01 vs 0.87 ± 0.01 vs 0.67 ± 0.01; p < 0.05). We found a positive correlation between Pulsatility Index of Umbilical Artery and maternal BMI (r(2)  = 0.7; p < 0.05). CONCLUSION: There is a positive correlation between BMI and pulsatility index of umbilical artery. These findings suggest that obesity has a negative effect on feto-placetal vessels. If our data will be confirmed, maternal BMI should be considered in evaluation of umbilical Doppler velocimetry.