Blood pressure before pregnancy can determine sex of baby

A link has been found between a mother’s blood pressure before conception and the gender of their baby

Scientists in Canada have discovered that a mother’s blood pressure can predict the sex of a baby before it is even conceived. Blood pressure readings at around 26 weeks before insemination determine whether she will give birth to a boy or a girl, with high systolic blood pressure signalling a boy, and low, a girl. The mean systolic blood pressure for women who had boys was 106mmHg, compared to 103mmHg for girls.

Dr Ravi Retnakaran, endocrinologist at Mount Sinai Hospital in Toronto, said; “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.”

The study looked at 1,411 newly married Chinese women, all of whom were trying to become pregnant. Their blood pressure was checked at around 26 weeks before conception, and then monitored throughout pregnancy. After taking into consideration factors such as age, smoking, BMI, cholesterol, systolic blood pressure before pregnancy was found to determine gender.

There are other factors that can affect the gender of a baby, too. During stressful events, such as wars and natural disasters, the proportion of boys and girls born can differ.