Conceiving a child as quickly as possible after discontinuing contraception may not have any affect on the sex of the baby.
The sex of a child is important to many couples, and there are many techniques still used by prospective parents today in the hopes of tipping the scales in favor of the desired gender. Some of the persistent old wives' tales about conception and pregnancy have been scientifically proven to be ineffective. There's one, however, that has so far not been shown that it does—or doesn't —have an effect on sex.
The idea is that the shorter the time it takes a woman to conceive after she starts trying for a baby, the greater the chance that she will give birth to a boy rather than a girl. Previous studies to prove or disprove this idea have been inconclusive, which is why researchers from the National Institutes of Health (NIH) created a study to find the truth. The authors cite the likelihood of problems in previous, retrospective studies to be the main reason why this folklore had yet to be debunked. Instead, this study used prospectively observed time-to-pregnancy (TTP) to reduce potential errors.
The NIH recruited more than 500 couples who were ready to stop using contraception and try for a pregnancy. Researchers followed the women in the study for one year, or until they gave birth. During this time, information such as TTP, income, smoking status, and BMI, as well as age of both parents, were recorded. The study authors controlled for these variables and correlated them with the sex of the 234 singleton children included in the study. The results, published in the September 2014 issue of Fertility and Sterility, showed that there was no consistent connection between the sex of a baby and how quickly he or she was conceived.