Okay, stop me if you've heard this old wive's tale: There's a pregnant mom I know and she had lots and lots of heartburn during her pregnancy. And now she just had her baby and the baby has more hair than I've ever seen. True statement! (Actually, it is...)
According to researchers from Johns Hopkins University, there is a correlation between the severity of heartburn in pregnancy with the amount of hair your baby has at birth. While the study was small, it may be that the same hormones that control the basics of heartburn related illnesses also correspond to hair growth of the fetus, researchers report in the journal Birth.
Costigan KA, Sipsma HL, DiPietro JA. Pregnancy folklore revisited: the case of heartburn and hair. Birth. 2006 Dec;33(4):311-4.