eli5: how come only some babies get fetal alcohol syndrome from mother’s alcohol consumption during pregnancy?

Question

also how come some heavy drinking mothers give birth to perfectly healthy babies?

In: 24

Answer 1

Recent research involving mothers who denied alcohol consumption indicates that the father’s alcohol consumption may contribute to FASD.

https://today.tamu.edu/2023/04/12/fathers-alcohol-consumption-before-conception-linked-to-brain-and-facial-defects-in-offspring/#:~:text=Now%2C%20research%20at%20Texas%20A%26M,exclusively%20examines%20maternal%20alcohol%20exposure.