Introduction
Body mass index (BMI) is commonly used to classify obesity but does not account for distribution of adipose tissue. Australian studies have shown that abdominal subcutaneous fat thickness (SCFT) is associated with adverse pregnancy outcomes.1,2
Objectives
This single centre prospective longitudinal cohort study aimed to confirm if the SCFT measured at the routine 18-22 week ultrasound, is associated with maternal pregnancy outcomes.
Methods
Ethical approval was obtained. Data was collected on singleton pregnancies, at a tertiary centre with 4200 annual deliveries. Three abdominal SCFT measurements were obtained from standard cervix-placenta images from eligible women and averaged by one trained operator. Maternal antenatal and outcome data were obtained from the electronic patient record and the institutional obstetric database. Maternal outcomes included: gestational diabetes, gestational hypertension/pre-eclampsia, delivery < 37 weeks and mode of delivery. Pearson’s correlation coefficient was calculated and unadjusted logistic regression modelling utilised.
Results
Data was obtained for 1071 women delivering between February 2015 and June 2016. Their mean (SD) age was 30.6 (5.5) years; 439 (41.0%) were nulliparous and 747 (69.7%) Caucasian. The median (IQR) booking weight was 78 (69-90) kg and BMI was 24.39 (21.71-28.35) kg/m2; 203 (18.9%) had a BMI >30 kg/m2, 90 (8.4%) had PIH and 84 (7.8%) had gestational diabetes. The median (IQR) SCFT was 15.38 (12.8-19.6) mm. The booking BMI and SCFT were highly correlated (r=0.738, R2=0.54). Each additional 1mm increase of SCFT was significantly associated with an increased odds of experiencing gestational hypertension/pre-eclampsia (OR=1.096, 95%CI: 1.063-1.130), caesarean delivery (OR=1.058, 95%CI: 1.036-1.081) and gestational diabetes (OR=1.053, 95% CI: 1.022-1.085).
Conclusions
SCFT was correlated with booking BMI and increased SCFT was associated with gestational hypertension/preeclampsia, mode of delivery and gestational diabetes. This population had fewer Caucasian women and reduced SCFT, compared with published data.1,2 SCFT requires further exploration as a predictor of pregnancy outcomes.