Anthropometric and ultrasound measures of maternal adiposity in the first trimester of pregnancy

Aim: Estimations of central adiposity in pregnancy is a difficult undertaking due to physiological changes that occur in the body. Therefore, the value of some anthropometric measures particularly in pregnancy, such as body mass index (BMI), waist and hip measures are in doubt. The aim was to compare ultrasound (US) measured abdominal subcutaneous fat (USSFT) with other simple anthropometric methods for obesity assessment, evaluating these measures in pregnancy. Method: Recruited from a larger study, anthropometric measurements were performed between 11–14 weeks’ gestation on 575 women. Measuring height, weight, hip, waist circumference, skin-folds of the triceps, thigh and supra-iliac and USSFT. Percentage maternal fat mass was calculated using skin-fold measures. Correlations of these measures were performed to gauge relationships. Results: The anthropometric measures demonstrated good correlation (0.54–0.93) between individual adipose measures skinfolds, waist, hip, waist to height ratio (WSR) and USSFT with BMI, percentage fat mass and weight. USSFT correlated well with all anthropometric measures (0.54–0.73) correlating best with waist, WSR, BMI and weight. Waist/hip ratio demonstrated a poor correlation with USSFT, BMI, percentage fat mass and weight (0.3–0.41). Mean anthropometric measures were stratified across BMI categories describing adiposity distribution. Conclusion: USSFT correlates well with most anthropometric measures in early pregnancy. Limitations of the gravid uterus on waist measurements, hydration and compressibility of skin-fold measures and pregnancy influences on weight and BMI assessments could be overcome using US measures. There is a potential for post hoc evaluation using US for pregnancy complications. Maternal research could benefit from a more accurate measure of adiposity.