The boffins analysed data covering all the births in Norway between 1967 and 2004, studying information available on men and women and their first born children. This meant that the researchers looked at the data of a total of 387,555 parent and child units. They found that it was twice as likely that babies of men and women who had been delivered in breech would also be born in the same position, reports the BMJ. Researchers also found that babies delivered naturally, not by caesarean, were at the biggest risk of a breech delivery.
They then noted that the risk was equally high if one or both parents were the result of a breech delivery, after studying 35,056 men who had children with two different women.
This, the boffins suggest is a strong indication that the risk of breech delivery is inherited, and that genes predisposing to a breech delivery are transferred to the foetus which then increases the risk of the mother having a breech delivery.
It was also noted that only full-term babies were at an increased risk. Breech delivered parents, born prematurely, had no increased risk of breech delivered offspring. Breech deliveries carry significantly greater risks for the baby: they are more likely to die or suffer from health problems.