Midwife Hannah had always longed for a daughter, but, when she met future husband Mark, he broke the news to her that she would only be having sons.
The last girl born was his great-great aunt Bessie, who was born 200 years ago - the same year as Charles Darwin.
“He said you’ll probably have two boys and I accepted it, but always thought it would be nice to have a girl," she explained on ITV's This Morning.
But Hannah wasn't willing to take the news sitting down - and, after giving birth to a boy in 2005, decided to try the Shettles Method.
This conception theory claims that male sperm swim faster but don’t live as long, while female sperm swim slower but last longer.
In a bid to take advantage of this, Hannah and Mark began having sex two to three days BEFORE ovulation, as opposed to after, so that only the female sperm would be able to reach the egg.
And, last year, the pair finally welcomed a baby girl to their family.
Speaking about his daughter, Mark said: “I was astonished - I’ve got three boys, my brother has got a boy.”
Although the couple cannot be sure the science was the reason behind breaking the 200-year run, they have said that they won’t be testing it out again.
“Maybe it was something to do with it, maybe it was complete luck," explained Hannah.
"I had to try it, but I’ve got a boy and a girl now and I’m sticking with that."
The Shettles Theory also advises couples on the best sex positions, insisting those who would like a boy should try those that offer 'deep penetration' (such as doggy style), whilst those who are trying for a girl should choose 'shallow penetration' options, such as the missionary position.
This Morning's Doctor Dawn also added that women who eat cereal for breakfast and have a high potassium diet are more likely to have a boy, compared to women who don't have breakfast.
Despite this, however, doctors have said that there’s no science behind the gender of your baby - and that it is always a “50/50 chance” as to whether you will conceive a boy or a girl.
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