Is there any way to influence a baby's sex?

Answers from Roger W. Harms, M.D.

The short answer is no — there's not much the average couple can do to affect a baby's sex.

While countless old wives' tales suggest that everything from a woman's diet to sexual position during conception can affect a baby's sex, these theories remain unproved. Likewise, researchers have found that timing sex in relation to ovulation — such as having sex days before ovulation to conceive a boy or closer to ovulation to conceive a girl — doesn't work.

Rarely, couples face the agonizing problem of knowing they could pass a genetic trait to a child of a specific sex — usually a boy. Under those special circumstances couples might use high-tech interventions to influence the chance of conceiving a girl. For example:

  • Preimplantation genetic diagnosis. With this technique — which is used in combination with in vitro fertilization — embryos are tested for specific genetic conditions and sex before they're placed in a woman's uterus.
  • Sperm sorting. Various sperm-sorting techniques — which require artificial insemination or in vitro fertilization — can be used to reduce the likelihood of passing on a genetic condition, as well as select a child's sex.

Despite the feasibility of these techniques, they're rarely used when choosing a baby's sex for personal reasons is the only motivation.

Feb. 07, 2014 See more Expert Answers