Why IVF raises the chance of having a baby boy

IVF makes parents more likely to have a baby boy than a girl – and now we know why.

When IVF doctors choose one of several embryos to transfer for pregnancy , they are unintentionally selecting male embryos over female ones, scientists have found.

That is because embryos are chosen based on how well they are growing and developing, and male embryos grow slightly faster in the first few days after conception. New Feature

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“When you equate faster with better, then what happens is you favourably select male embryos over female embryos,” said Dr Helen O’Neill, a fertility specialist at University College London.

“The tools we’re using are selecting males,” added Dr O’Neill, who led the research and presented it at New Scientist Live