Your blood's
Rh factor is either positive (Rh+) or negative (Rh-).
The Rh+ gene is more common than the Rh- gene, and is dominant.
- If one of your two Rh genes is Rh+ and the other
is Rh-, your blood type is Rh+.
- It takes a pair of Rh- genes to
make your blood type Rh-.
When an Rh- woman conceives with an Rh+ man, it is probable that
their offspring will be Rh+.
- If the father has two Rh+ genes, the fetus will
inherit an Rh+ gene. That Rh+ gene, paired with the mother's Rh- gene, will
result in an Rh+ fetal blood type.
- If the father has one Rh+ and
one Rh- gene, the fetus will inherit one of them, either:
- An Rh+ gene, resulting in an Rh+ fetal blood
type, or
- An Rh- gene which, when paired with the mother's Rh- gene,
results in an Rh- fetal blood type.
