What heartburn while pregnant could mean about your baby
Some women report heartburn during the pregnancy and the science exists to explain why.
But first we take it to the baby in the womb’s first poop. What that is, is pretty pretty weird. In the second trimester, babies develop a fine layer of hair called lanugo. In the third trimester they shed it and eat it, then poop it.
So the first poop is the digested remains of their hair.
The hair on their head is a bit different. Not all babies in the womb have it.
In 2006, for a study in the journal Birth, a team of researchers from Johns Hopkins University followed 64 women throughout their pregnancies, 28 of whom reported moderate or severe heartburn.
Within that group, 23 women ended up having babies of average or above-average hairiness. On the opposite end of the spectrum, of the 12 women who reported no heartburn at all, ten of them gave birth to kids who were less hairy than the average newborn.
But here’s a perfect example of correlation not equaling causation. The heartburn wasn’t a result of the hair, or vice versa. Rather, the study authors argued, both were caused by a third factor: pregnancy hormones.
Specifically, the same hormones that contribute to hair growth in the womb have also been shown to relax the muscles that keep stomach acid contained in the stomach.
So you can technically blame the baby for that fiery pain in your chest, but the link isn’t quite as direct as the old wives’ tale implies.