Is Having a Big Baby Hereditary?

True or false: If you were a big baby at birth, your babies will be big too. We've got the answer.
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ByJames O’Brien, MD
OB-GYN
Updated
May 2017
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Yep, giving birth to big babies can be hereditary. In general, babies tend to be in the same weight range as their parents. In other words, if you were nine pounds, eight ounces at birth, it’s incredibly unlikely that you’ll give birth to a five-and-a-half-pound peanut.

Of course, there are other factors that can affect baby’s birth weight, though, including:

• Birth order. Younger siblings tend to be larger than their older brothers/sisters.

• The baby’s sex. Newborn baby boys typically weigh more at birth than girls.

• Your weight. Heavier moms are more likely to give birth to larger babies.

• Your pregnancy weight gain. The more weight you gain during your pregnancy, the more likely you are to have a bigger-than-average baby.

• A history of diabetes or gestational diabetes. High blood sugars can cause the baby to gain weight. That’s why it’s so important to keep your blood sugars under control during pregnancy.

• A history of large babies. If your last two babies were both eight pounds-plus at birth, you’ll probably have another eight-pounder (or so).

Don’t freak out, though, if you were a “big baby.” Women’s bodies are designed to give birth, and odds are, you and baby will do just fine.

Plus, more from The Bump:

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