Correlation between Maternal Characteristics during Early Pregnancy, Fetal Growth Rate and Newborn Weight in Healthy Pregnancies

Background: The objective of this study was to evaluate the association between maternal characteristics in early pregnancy and fetal growth (FG) and birth weight (BW). Methods: A prospective cohort study was performed in unselected pregnant women who attended an ultrasound evaluation at 11-14 weeks of pregnancy. Medical history, biochemical blood tests, biophysical variables and fetal weight at 20-25 and 30-36 weeks as well as the BW were assessed. Bivariate and multivariate linear models were constructed. Results: In all, 543 patients with normal pregnancy and labor were selected. The multiple regression analysis showed a statistically significant association between maternal body mass index (BMI) in early pregnancy and the uterine artery pulsatility index (UtAPI) in the first trimester with BW (p < 0.0008) and with the ratio of fetal growth between the second and third trimesters (p < 0.0001). No correlation was found between these variables and first trimester levels of hemoglobin or glycemia. Conclusion: Maternal first trimester BMI and UtAPI correlate with the rate of intrauterine FG and with the BW. This evidence highlights the influence of maternal first trimester variables on fetuses with normal growth and the potential role of these variables in fetal programming.