For better or for worse (depending on your current, uh...life goals), having sex twice an hour can make your semen three times more fertile, say researchers at London’s North Middlesex Hospital.

In the study, 73 hoping-to-conceive couples were given intrauterine insemination (IUI), which places sperm directly into the womb.

IUI typically has about a 6% success rate—but when the sperm was from a fresh batch taken within 60 minutes of the first milking, the rate jumped to 20%—just 4% less than in vitro fertilization.