I had absolutely NO heartburn during my pregnancy ... Yet my daughter was born with the biggest mop of dark hair - even one of the (male) midwives that was present at the birth came to visit me the next day purely to see 'the baby with a ton of hair' again ... and he had been doing midwifery for over two decades

To think I myself as a baby had no hair until I was 18mths old and then it was fine & like a silver blonde

DD got her Daddy's hair ... he had heaps of dark hair when he was born