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 32weeks of gestation, were recruited. According to BMI, they were divided into underweight (BMI+0weeks 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; p2=0.7; p