Characterization of cardiac remodeling during pregnancy in rats

During pregnancy, an increase in blood volume occurs to compensate for fetal development, resulting in cardiac hypertrophy. For the majority of women, this physiological cardiac hypertrophy resolves following pregnancy. Prolonged cardiac hypertrophy can lead to heart failure. We propose that by studying the biochemical mechanisms that mediate healthy cardiac remodeling associated with pregnancy, we will gain a better understanding of mechanisms involved in pathological cardiac hypertrophy. To determine the biochemical changes that occur during pregnancy induced cardiac remodeling, we subjected rats to timed matings and collected morphological and biochemical data from not pregnant, 19 days pregnant, and 24 hours postpartum. The heart weights increased approximately 10% on the 19th day of pregnancy as compared to their non‐pregnant littermates. Histological analysis confirmed an increase in cardiomyocyte size associated with the increase in heart size. Real‐time PCR analysis revealed alterations in expression of some gene markers of hypertrophy during pregnancy and postpartum. Our data demonstrates pregnancy induced cardiac remodeling in the rat involves both morphological and biochemical changes.