Many women dream of having a baby girl, but there is only one sure way to conceive a baby girl, according to the Stanford School of Medicine. That way, called preimplantation genetic diagnosis (PGD), involves fertilizing an egg, then testing the embryo to find out if it’s a boy or girl before implanting it in the uterus. This expensive procedure is controversial but allowable for family balancing in some countries, including the United States. There are other, less invasive, ways of increasing your chances of conceiving a girl.

Know When You Ovulate

The “O+12” method advocates having intercourse about 12 hours after you ovulate. This method is based on a study published in the journal “Fertility and Sterility”, which found that 63 percent of the women who had intercourse the day after ovulation went on to have baby girls.

Go on a Diet

A low-calorie intake might help you conceive a girl. A study performed by the University of Exeter found that the women in the study group who consumed the least amount of calories were the most likely to conceive girls. A diet high in calcium and magnesium was also found to increase the chances of having a girl.

Sort the Sperm

A company called MicroSort has developed technology that will separate the X sperm from the Y sperm, allowing the woman to use only the X sperm to fertilize the egg. The sperm can be used for intra-uterine insemination (IUI) or in-vitro fertilization (IVF). This technology has a 91 percent success rate when used to try to conceive a girl, according to the Stanford Medical Center website.

Reduce Sperm Count

The Y sperm are faster but weaker than the X sperm, according to the Stanford Medical Center website. The X sperm are longer-lived and stronger. To increase your chances of conceiving a girl, try lowering the sperm count and weakening the Y sperm. The man could ejaculate several times in a week before trying to conceive, or he could immerse himself in a hot tub, as warm temperatures weaken sperm.