"Five minutes is probably sufficient," he said. "Sperm travels very, very rapidly. If you get up within the minute there may be some leakage."
"In our practice I've never heard of anyone who gets up immediately," Lobo said. "The standard is 10 minutes. Women who are asked to get up immediately may have a stress response." Volume of sperm also plays a role with more sperm upping the odds of pregnancy, he added.
There's more on infertility at the American Society of Reproductive Medicine.
SOURCES: Inge Custers, Ph.D., student and registrar, Centre for Reproductive Medicine, Academic Medical Centre, Amsterdam, The Netherlands; Roger Lobo, M.D., professor, obstetrics and gynecology, Columbia University and president-elect, American Society of Reproductive Medicine; Peter McGovern, M.D., director, Division of Reproductive Endocrinology and Infertility, Hackensack University Medical Center, professor and director, Division of Reproductive Endocrinology and Infertility, University of Medicine and Dentistry of New Jersey, and medical director, University Reproductive Associates, Hasbrouck Heights, New Jersey; Oct. 30, 2009, BMJ, online