Gestational Obesity Impairs Maternal Glucose Metabolism in Post-Partum Ewes

This study determined the effects of gestational obesity on the short- and long-term metabolic statuses of post-partum mothers and whether obesity management during pregnancy could attenuate these effects. At 120 days prior to estrus, eight ewes received 100% of the National Research Council (NRC) nutrient requirements (control group), and twenty-four ewes had free access to feed (obesity induction). Embryos from superovulated ewes with normal body condition were transferred to the uteri of control-fed or obese ewes on day 6 post-estrus to generate genetically similar singleton pregnancies. Thirty-five days after embryo transfer, eight obese ewes were subject to restricted feeding (65% of feed intake for the 100% NRC-fed control group) until parturition, and the remaining sixteen obese ewes (eight ewes/group) continued to have free access to feed throughout gestation. Following parturition, all but one group of obese ewes (that continued to have free access to feed) were fed 100% of NRC nutrient requirements. At post-partum days (PPD) 1 and 150, glucose tolerance tests were conducted with ewes. At both PPD1 and PPD150, obesity resulted in insulin resistance, impairment of whole-body glucose utilization, increased levels of circulating leptin, and altered profiles of amino acids in plasma, and these effects were attenuated in ewes receiving obesity management during or after gestation. At PPD150, obesity increased circulating levels of ammonia and urea in ewes, which were prevented by realimentation to 100% NRC requirements. These results indicate that weight reduction in obese ewes during pregnancy or after parturition can ameliorate the adverse metabolic effects of gestational obesity in ewes.