Impact of pregnancy and vaginal delivery on the passive and active mechanics of the rat vagina

摘要: Remodeling of vaginal extracellular matrix and smooth muscle likely plays a critical role in reducing the risk maternal injury during delivery by altering mechanical properties to increase distension reduce stress. Long-Evans rats were divided into five groups examine passive active contractile throughout pregnancy postpartum: virgin (n = 17), mid-pregnant (Day 14–16, n 12), late-pregnant 20–22, 14), immediate postpartum (0–2 h after delivery, 4 week 15). Longitudinal sections tissue loaded failure uniaxially for or examined. For mechanics, tangent modulus decreased 45% mid-pregnancy immediately (p < 0.001). The ultimate strain continuously increased up 43% higher than animals 0.007) group. maximal force was 36–56% lower through animals, significantly more sensitive K+ 0.003). changes observed rat vagina are consistent with what would be expected from that is remodeling maximize its ability distend at time facilitate passage fetus minimal injury.