Background Obesity in pregnancy confers substantial short-term and long-term risks to the mother and fetus. In pregnancy, physiological adaptation of lipid metabolism occurs, with lipid accretion and weight gain in early pregnancy, but enhanced lipolysis as a consequence of progressive insulin resistance in late gestation. In non-pregnant individuals, obesity is associated with dysregulation of adipose tissue function, and related local and systemic inflammation. The authors hypothesised that obesity subverts the physiological adaptation of lipid metabolism in pregnancy and that this contributes to adverse outcomes.

Aim The authors sought to quantify expression of genes involved in the regulation of lipid metabolism and inflammation in subcutaneous and visceral adipose tissue of pregnant women and correlate with booking body mass index (BMI).

Methods The authors obtained subcutaneous adipose tissue from women with uncomplicated singleton pregnancies undergoing elective caesarean section (n=39, booking BMI 20.4–51.0 kg/m²). The authors quantified gene expression by real-time qRT-PCR. The authors also compared gene expression in paired subcutaneous and visceral adipose tissues in a subset of women (n=9).

Findings A positive correlation was observed between booking BMI (p=0.0352, r=0.3427) and expression of 11-HSD1, but not glucocorticoid receptor, lipoprotein lipase, hormone sensitive lipase (HSL), adipose triglyceride lipase, adiponectin, tumour necrosis factor or monocyte chemoattractant protein 1. In lean but not obese women, transcript levels of insulin receptor substrate 1 (p=0.029) and HSL (p=0.034) were greater in visceral than subcutaneous adipose tissue.

Conclusion Pregnancy appears to dampen differences in adipose tissue gene expression that are normally found between obese and lean women and between visceral and subcutaneous adipose tissue.