Difference in Visceral Adipose Tissue in Pregnancy and Postpartum and Related Changes in Maternal Insulin Resistance

To measure the difference between first-trimester and postpartum visceral adipose tissue (VAT), the agreement of this difference with change in body mass index, and whether a difference in VAT is associated with insulin resistance or glucose mishandling.

Prospective study of 93 women with singleton pregnancies without a history of diabetes. Visceral adipose tissue depth was sonographically assessed at 11 to 14 weeks and at 6 to 12 weeks postpartum. Metabolic measures, sampled at 24 to 28 weeks and 6 to 12 weeks postpartum, included homeostatic model assessment of insulin resistance, insulin sensitivity index composite, and area under the 75-g oral glucose tolerance test curve.

First-trimester VAT depth explained only 37% (95% confidence interval [CI], 22-52) of the variation in postpartum VAT depth. There was limited agreement between the net change in postpartum minus first-trimester VAT depth and that same net change for body mass index (Cohen's kappa, 0.26; 95% CI, 0.05-0.47). Those with a net gain in VAT depth demonstrated poorer insulin sensitivity index postpartum than women with a net regression in VAT depth-a difference of -2.0 (95% CI, -3.3 to -0.69).

Sonographic assessment of postpartum VAT is feasible and may provide insight to metabolic changes between pregnancy and postpartum, beyond body mass index.