TIME child development

Health of Mom Key Factor in Baby Size, Study Says

hands on pregnant stomach
Alex Mares—Asia Images RM/MantonGetty Images

And not race or ethnicity, researchers find

The size of a baby at birth has a significant impact on its future health, and a far-reaching new study shows that the greatest disparities in infant size worldwide are due to mothers’ health, not their race or ethnicity.

The large study, led by Oxford University researchers, looked at 60,000 pregnancies in urban areas in Brazil, China, India, Italy, Oman, Kenya, the U.K. and the U.S. During women’s pregnancies, the researchers used ultrasounds to measure the babies’ bone growth in the womb. When the babies were born, they measured their length and head circumference. They found that the babies’ growth in the womb and their size at birth were very similar across countries, if their mothers were healthy and well-educated.

The study debunks the belief that race or ethnicity are the primary factors for a baby’s size at birth. The good news is that the findings suggest if a mother is educated, healthy and well-nourished, her child has an equal shot at good health in the womb and beyond. But the bad news is that women in less fortunate circumstances are already at a disadvantage when it comes to raising a healthy child.

“Currently we are not all equal at birth. But we can be,” lead study author Jose Villar, a professor in the Nuffield Department of Obstetrics & Gynaecology at University of Oxford said in a statement. “Don’t tell us nothing can be done. Don’t say that women in some parts of the world have small children because they are predestined to do so. It’s simply not true.”

The researchers argue that all mothers can have a similar start if they can be educated and nourished and have access to infection treatments and adequate antenatal care.

The ultimate goal of the study is to create international standards for babies’ optimal growth.

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