What Harm Does Intake Of Meth Cause During Pregnancy?

Hi i have a dear friend who has been clean from meth since she found out she was pregnant but the other day she went around her ex and did it again she swears just once but she 37 weeks pregnant and im scared it will show up if her and the baby if they get drug tested after birth she has promised to leave this man alone and is now living with me but i herd if you have medicaid the hospital has to drug test both her and the baby anyways will she be ok or will it still be in the babys stool