Is Pregnancy Weight Gain Connected to Baby's Gender?

Cropped high angle shot of a pregnant woman weighing herself on a scale
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People are always looking for patterns to connect pregnancy symptoms with baby's gender. And while we know that even educated guesses at a baby's sex in the womb can't predict the baby's gender identity, many parents-to-be mull over small signs predicting a little-one-on-the-way's sex. And while many such connections are just myth-based, there's hard data to show that the latest pattern to emerge is totally grounded in reality: The more weight you gain during pregnancy, the more likely you are to deliver a boy.

This news comes from a study published in PLOS One, which analyzed data from nearly 70 million births over a close to a quarter-century. It suggested that increased pregnancy weight correlated with male babies.

When moms-to-be gained about 20 pounds, they delivered about 49 percent male babies—so under half. But when pregnant women gained 40 pounds, they delivered boys about 52.5 percent of the time. And when they gained 60 pounds, they delivered boys a notable 54 percent of the time. (Above 60 pounds, the connection went away.)

Why is this the case? Well, it's not completely known. But Kristen J. Navara, the doctor who analyzed the data, wrote, "It is possible that this relationship results from the fact that male embryos and fetuses have higher metabolic rates, and likely need more caloric energy to develop successfully."

Given that I delivered a boy and girl at the same time following my twin pregnancy, I'm never a great test of these theories. But if you're looking to read the tea leaves while you're waiting for your baby to arrive (and then grow into a person with fully-fledged gender identity), you can have some fun reading the scales.

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Alesandra Dubin is a new twin mom, as well as a Los Angeles-based writer and the founder of home and travel blog Homebody in Motion. Follow her on Facebook, Google+ and Twitter.

Photo courtesy of Shutterstock

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