My best friend is having a csection on april 28 she just stopped smoking marijuana a couple days ago.. will it show up in her or the baby system? does every hospital test every mother and baby? she lives in ohio?

If the baby's meconium, first stool, is tested, it will likely be positive for use of weed. Not every baby is tested, unless there is a medical or social reason to do that. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get HPV and Covid vaccines.