Effects of seminal ejaculate on the biomechanical properties of chorioamniotic membranes.

We investigated the effects of seminal ejaculate on the biomechanical properties of chorioamniotic membranes obtained and processed immediately after normal term vaginal deliveries. Study samples were exposed to seminal ejaculate and control samples to buffered normal saline. Both the samples and controls were incubated for periods of 1, 4 and 24 hours, after which a load-deformation curve was derived for each. Four biomechanical parameters were analyzed for each sample and control: modulus of elasticity, rupture tension, work to rupture and strain to rupture. Exposure to seminal ejaculate was associated with an increase in the modulus of elasticity, work to rupture and rupture tension, reflecting a change in the elastic component of the mechanical properties. No significant change was observed in the strain to rupture. We hypothesize that these changes may indicate an alteration in the ability of chorioamniotic membranes exposed to seminal ejaculate to dissipate mechanical stress, resulting in their predisposition to premature rupture.