Did you know morning sickness can actually reveal something interesting about the sex of your baby?

You know all the usual old wives' tales about how you can predict the sex of your baby?

You know, based on things like whether or not your skin is acting up or if you crave sweet over savoury foods? Well, it turns out they are not the only indicator of what could be happening inside your tummy. According to a study of 1.6(!) million pregnancies in Sweden, lead researcher, Lena Edlund, and her team at Colombia University in New York, found that women who suffer from extreme morning sickness – also known as hyperemesis gravidarum (HG) – are less likely to give birth to sons. In fact, the study found that 56 percent of mothers suffering from severe sickness during pregnancy ended up having a baby girl. "Normally, slightly more boys than girls are born, we don’t quite know why that is," Edlund said. Fortunately, HG is quite rare, only appearing in one in ever 100 pregnancies each year, but can be utterly exhausting for those who have it, with some ending up losing weight during their pregnancies as they find it impossible to eat or drink without feeling ill. The Duchess of Cambridge famously suffered with extreme morning sickness during all her pregnancies, and was admitted to hospital ahead of the birth of her son, Prince George.