stylistic:style_transfer
Fertility

There are theories that the female orgasm might increase fertility. For example, it has been suggested that the 30 percent reduction in the size of the vagina could help clench the penis (much like, or perhaps caused by, the pubococcygeus muscles), which would make it more stimulating for the male (thus ensuring faster or more voluminous ejaculation). The British biologists Baker and Bellis have suggested that the female orgasm may have a peristalsis or "upsuck" action (similar to the esophagus ' ability to swallow when upside down), resulting in the retaining of favorable sperm and making conception more likely. They posited a role of female orgasm in sperm competition.