Research has found that taking aspirin before sex may increase a woman's likelihood of conceiving a boy, if the woman has had a history of miscarriages.
The theory goes that in some cases, the immune system can see an embryo as a foreign intruder, promoting an inflammatory response in the body.
As male embryos are thought to be more vulnerable to these changes in the body than female embryos, the inflammation can reduce the chances of having a boy.
In a recent study at the Eunice Kennedy Shriver National Institute of Child Health and Human Development, in the US, scientists put the theory to the test.
As part of the research, 1228 women with a history of miscarriages were given a low dose aspirin to take before sex, for as long as they were trying to get pregnant.