He's Positive, She's Negative: What's That Do to Baby?
He's Positive, She's negative; What's That Do To Baby?
By Carolyn Strange
A: It's always a good idea for any couple to think ahead and prepare for pregnancy, so Mom and baby can be as healthy as possible. When facing the potential for Rh disease, as you two are, it's even more important. You'll probably want to educate yourselves about Rh incompatibility. And in any case, make sure you find a health-care provider who understands Rh disease, and with whom it's easy to communicate.
One thing is clear -- your baby will have type O blood. What's not clear is whether your baby's blood will be Rh-positive or Rh-negative, and that's what makes all the difference.
Rh disease of the newborn arises from incompatibility of the Rh factor between the mother and baby. It's a bit simplistic, but you can think of the Rh factor as a protein that is either present (positive) or absent (negative) on red blood cells. Exact percentages vary with race, but most people are Rh-positive.