Will it be a little boy or girl? Any expectant mum wonders endlessly whether she’ll have a daughter or son, but it has always been left to chance – or so we thought…
Scientists now believe there may be a way to control the sex of your baby, and it’s all down to blood pressure.
As The Telegraph reports, researchers at Mount Sinai Hospital in Toronto have discovered that a woman’s blood pressure BEFORE she gets pregnant could have a previously unknown impact on whether she’ll have a boy or girl.
Their groundbreaking discovery has revealed that women with higher blood pressure were 45% more likely to have a boy than those with the lowest readings.
Researcher Dr Ravi Retnakaran says: ‘It suggests that a woman’s blood pressure before pregnancy is a previously unrecognised factor that is associated with her likelihood of delivering a boy or girl.’
High blood pressure can be caused by genetics as well as lifestyle factors including being overweight, not exercising enough and smoking.
The team made the connection while trying to work out what determines the sex ration in populations. They studied 1,400 women who were planning to try for a baby, giving them a medical at the start of the study and then again as soon as they become pregnant. The first check-up was given an average of 23.6 weeks before the women conceived.
A total of 739 boys were born, while the women welcome 672 baby girls.
Taking a number of factors into account, including age, cholesterol levels and BMI, the scientists noticed that women who had higher blood pressure before they became pregnant had a much bigger chance of conceiving a boy. While women with the highest readings had a 62% chance of having a son, those with the lowest readings had only a 43% chance.
Dr Retnakaran added: ‘This study suggests that either lower blood pressure is indicative of a mother’s physiology that is less conducive to survival of a male foetus or that higher blood pressure before pregnancy is less conducive to survival of a female foetus.
‘This novel insight may hold implications for both reproductive planning and our understanding of the fundamental mechanisms underlying the sex ratio in humans.’
Writing in the American Journal of Hypertension, the study authors said: ‘Indeed, higher maternal blood pressure before pregnancy emerged as an independent predictor of subsequently delivering a boy.’
While more research is needed to determine the cause of this link, some fertility experts remain sceptical about the findings. Geoffrey Trew, consultant in Reproductive Medicine and Surgery at London’s Hammersmith Hospital, told the Telegraph: ‘I haven’t heard anything like this before.
‘I would be very surprised that a BP measurement , which is notoriously variable, could dictate sex 26 weeks before, some reptiles can have sex differences due to temperature changes at the time of early fetal growth , but not 26 weeks beforehand.’
