Forget IVF gender selection. A team of scientists believe they have found a less controversial way of selecting a baby's gender without spending a cent: blood pressure.
Women can control whether they have a boy or girl by increasing or decreasing their blood pressure before conceiving, Canadian researchers have found.
Those trying for a baby who have higher blood pressure are more likely to give birth to a boy, according to the research.
The team at Mount Sinai Hospital in Toronto found that women with the highest blood pressure readings were about 45 per cent more likely to have a boy than those with the lowest.
Lead researcher, Dr Ravi Retnakaran, said their findings "suggest 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".
A total of 1411 newly married Chinese women who were planning to have a baby took part in the study.
The women underwent a medical at the start and during pregnancy and had their blood pressure, cholesterol, triglycerides, and glucose measured.
They were given a medical assessment at an average of 26.3 weeks before they conceived.
And their pregnancies resulted in the delivery of 739 baby boys, and 672 baby girls.
Researchers then took into account factors such as age, education, smoking, BMI, waist circumference, cholesterol levels, and blood sugar levels - in case these factors had an influence.
Their findings showed systolic blood pressure before pregnancy was higher in women who went on to welcome boys, than those who had little girls.
Those with the lowest readings had a 43 per cent chance of having a boy, while those with the highest had a 62 per cent chance.
The authors noted: "Indeed, higher maternal blood pressure before pregnancy emerged as an independent predictor of subsequently delivering a boy."