How Do Fetuses Respond to Their Mothers’ Food Choices?

It’s well known that exposing children to a wide range of foods and flavors early can help broaden their palates and encourage them to enjoy a varied diet. And according to a UK study led by Durham University researchers, that exposure could start even before they are born.

In the study, around 100 women who were 32 to 36 weeks pregnant consumed powdered vegetables. One-third had carrots, one-third had kale, and the remainder (the control group) didn’t have either. The women underwent ultrasound scans around 20 minutes later, providing the first known evidence that fetuses’ facial expressions change depending on what food their mothers eat.

The high-resolution 4D ultrasound images revealed that the majority of the fetuses whose mothers ate kale seemed to grimace, while most of those who ate carrots seemed to smile, apparently because of changes in the smell and flavor of the surrounding amniotic fluid. However, the researchers can’t be sure whether these facial expressions are simply muscle movements that automatically react to bitter versus sweet, or whether there is an emotional component. The ultrasound doesn’t provide enough evidence to say the kale made the fetuses unhappy, though it does underscore that in the third trimester, fetuses have fairly well-developed senses of smell and taste.

Perhaps the most interesting part of the research was a follow-up study that tested the taste preferences of the same babies who had had prenatal exposure. The mothers were asked to consume either kale or carrots every day during the last three weeks of pregnancy. Then, during their first month of life, the babies were exposed to the smell of carrots or kale. Preliminary findings indicate that the babies exposed to kale in the womb had fewer “cry-face” reactions when encountering it as newborns.

Eat your veggies, baby!