Despite most parents ultimately just wishing for a healthy baby, there are many cultural and social factors that can drive the desire for a baby of a particular sex. The medical technology for sex selection of embryos has existed in Australia for many years, but such an option is only available for medical reasons, such as sex-linked chromosomal disorder. This leaves parents who do have a gender preference looking for natural ways of predetermining the sex of their baby. In the s, the idea that timing sex around ovulation can tip the odds in favour of a girl or a boy was popularised by Shettles and Rorvik in the best-selling book How to Choose the Sex of Your Baby.
Can a Girl Get Pregnant by Another Girl?
Problems With Sperm - Women's Health Issues - MSD Manual Consumer Version
So goes a common belief, which asserts that sperm with Y chromosomes—those make male babies—swim faster, so you have a better chance of having a daughter if the sperm has to travel a long way to the egg. The idea has no scientific merit, but researchers have now found a way to make it true in mice, sort of. The scientists incubated mouse sperm in a mixture containing molecules that would bind to the receptors and activate them. The molecules slowed energy production in X-chromosome sperm while not affecting the Y-chromosome sperm at all, the team reports today in PLOS Biology.
School of Medicine. Sperm may be too few in number, move too slowly, or be structurally abnormal, or their passage out of the body may be blocked or disrupted. Clomiphene , a fertility drug, may increase the number of sperm, but assisted reproductive techniques may be needed. See also Overview of Infertility.
Since the late s, scientists have explored how to produce sperm where all of the chromosomes come from a female donor. Creating female sperm was first raised as a possibility in a patent filed in  by injecting a woman's cells into a man's testicles, though the patent focused mostly on injecting altered male cells into a man's testes to correct genetic diseases. In , Japanese scientists partially confirmed such techniques by creating chicken female sperm in a similar manner.