@manhal hello and let me also extend a warm welcome to Mayo Clinic Connect. Like Erika mentioned, we are not medically trained moderators, however, I did find what I believe may be a helpful resource for you.
Mayo Clinic: Rh Factor Blood Test: https://www.mayoclinic.org/tests-procedures/rh-factor/about/pac-20394960
Excerpt from the article:
If you're Rh negative, you might need to have another blood test — an antibody screen — during your first trimester, during week 28 of pregnancy and at delivery. The antibody screen is used to detect antibodies to Rh positive blood. If you haven't started to produce Rh antibodies, you'll likely need an injection of a blood product called Rh immune globulin. The immune globulin prevents your body from producing Rh antibodies during your pregnancy.
If your baby is born Rh negative, no additional treatment is needed. If your baby is born Rh positive, you'll need another injection shortly after delivery.