The answer: Before your pregnancy.
You can be born with antibodies.
If for example your mother is rhesus positive and you are rhesus negative, the blood of yours and your mother’s could have mixed when you were in the womb.
That means, your antibodies could have been building while she was pregnant with you meaning that you do not need a shot during your pregnancy, but before, as the antibodies can kill the fetus leading to a chemical pregnancy or miscarriage.
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When should antibody screening be done?
