Coitus during pregnancy has long been thought to be associated with adverse obstetric outcome. One critical problem in this connection is membrane rupture leading to preterm delivery. We studied 220 human chorioamniotic membranes and evaluated their tensile strength after exposure to human seminal fluid and specific prostaglandins. It was concluded that the biochemical constituents of seminal fluid do not have an adverse effect on the strength of human chorionic membranes.
Lavery JP, Miller CE. Effect of Prostaglandin and Seminal Fluid on Human Chorioamniotic Membranes. JAMA. 1981;245(23):2425-2427. doi:10.1001/jama.1981.03310480041026