Adiponectin is secreted from adipose tissue. Serum adiponectin levels are inversely correlated with body mass index (BMI) and also insulin resistance, independent of the BMI. A role for adiponectin in the development of insulin resistance has been implied in pregnancy. However, no studies have been performed to describe the individual longitudinal course of adiponectin in normal pregnancies. Therefore, we measured serum adiponectin during and after normal pregnancy in 11 healthy women. Serum levels peaked in midpregnancy and the lowest levels were seen in late pregnancy. An inverse association with maternal BMI was observed.