[IzzieC (OP)]

Jeff asks

"What are the complications of marrying someone of blood type A-, when I am B+?"

Can you help?

[evan_au]

In the past, a mother who was Rh- (the "-" at the end of the blood type), having a baby with a man who was Rh+ (the "+" at the end) had a chance that a second or subsequent babies could die from Rh disease.
- If the baby's blood mixes with the mother's bloodstream during birth, the mother's immune system can develop a permanent response against the Rh factor. This is dangerous for the next baby.
- The reverse scenario does not carry this risk (ie father Rh-, mother Rh+).

However, since the 1960s, mothers in this situation are now given an injection of Rh antibodies after birth of the baby, so her immune system does not get activated, with dire consequences for a subsequent baby. These injected antibodies dissipate after a few weeks. Sometimes additional injections are given during the pregnancy.
See: https://en.wikipedia.org/wiki/Rh_disease