I coulda told them that

Mom's heartburn is linked to babies' hair

A small study may confirm what was thought to be a folk tale — the notion that mothers who suffer from heartburn during pregnancy give birth to babies with heads of hair.

Researchers at Johns Hopkins University conducted a study intending to put the claim to rest; instead they confirmed it.

Their study followed 64 pregnant women, including 78 percent suffering from some form of heartburn.
Here's what they learned:— Of the 28 women who reported moderate to severe heartburn, 23 had babies withaverage or above-average amounts of hair.—

Ten of 12 women who reported no heartburn had babies with little or no hair.

Researchers linked the hair to high levels of estrogen and other hormones that can cause heartburn in some women. Those same hormone levels are linked to increased hair growth for unborn babies.