Supplementary Material for: Birth Weight and Neonatal Adiposity Prediction Using Fractional Limb Volume Obtained with 3D Ultrasound

<b><i>Introduction:</i></b> The objective of this investigation was to study fetal thigh volume throughout gestation and explore its correlation with birth weight and neonatal body composition. This novel technique may improve birth weight prediction and lead to improved detection rates for fetal growth restriction. <b><i>Materials and Methods:</i></b> Fractional thigh volume (TVol) using 3D ultrasound, fetal biometry and soft tissue thickness were studied longitudinally in 42 mother-infant pairs. The percentages of neonatal body fat, fat mass and fat-free mass were determined using air displacement plethysmography. Correlation and linear regression analyses were performed. <b><i>Results:</i></b> Linear regression analysis showed an association between TVol and birth weight. TVol at 33 weeks was also associated with neonatal fat-free mass. There was no correlation between TVol and neonatal fat mass. Abdominal circumference, estimated fetal weight (EFW) and EFW centile showed consistent correlations with birth weight. Thigh volume demonstrated an additional independent contribution to birth weight prediction when added to the EFW centile from the 38-week scan (p = 0.03). <b><i>Conclusion:</i></b> Fractional TVol performed at 33 weeks gestation is correlated with birth weight and neonatal lean body mass. This screening test may highlight those at risk of fetal growth restriction or macrosomia

Correlation of maternal body mass index with umbilical artery Doppler in pregnancies complicated by fetal growth restriction and associated outcomes

Objective To evaluate the correlation between Umbilical Artery (UA) Doppler and its feasibility across categories of maternal BMI in the presence of foetal growth restriction (FGR). Methods 1074 Singleton pregnancies with suspected FGR on ultrasound examination between 24+0 and 36+0 weeks' gestation were reviewed. Evaluation of the UA Doppler was performed at 1‐2 weekly intervals. Abnormal UA Doppler findings and delivery outcomes were compared between the different maternal BMI categories. Results Increased UA pulsatility index (PI > 95th centile) was reported in 81% of obese category 2 patients (BMI <35 ‐ 39.9 kg/m2) compared to a 46% incidence in the remaining categories, normal (BMI <24.9 kg/m2), overweight (BMI <25 ‐ 29.9 kg/) and obese class 1 (BMI <35 ‐ 39.9 kg/m2) (p = 0.001). In absent or reversed end diastolic flow (AEDF/REDF) we found an increasing incidence across the BMI categories (4%‐25%) (p<0.0001). Higher maternal BMI was associated with Lower birthweights and higher C‐section rates. Increasing maternal BMI did not affect successful assessment of UA Doppler. Conclusion There is a positive correlation between increasing maternal BMI and abnormal UA Doppler findings in FGR. Maternal BMI may be considered as an additional risk factor when evaluating UA Doppler for placental insufficiency