Tranfusion Options For Pregnant Women

This information sheet was prepared for pregnant women and persons considering donating blood for them.

AUTOLOGOUS (SELF-) DONATION (for pregnant women)

Since donating blood during pregnancy is a relatively new procedure, medical experience with this type of donation is less than with regular donations. Donation appears to be safe for both mother and fetus. There is, however, concern that if a pregnant woman develops a fainting (hypotensive) reaction associated with a drop in blood pressure (an event occurring in 2 - 3% of healthy non-pregnant donors), the blood flow to the fetus may be reduced, possibly causing an adverse effect on the fetus. The magnitude of this risk is not known. As with any medical procedure associated with risk, a decision to pursue autologous donation during pregnancy should balance the potential safety and emotional benefits to the mother of receiving her own blood against the risks to the fetus from a hypotensive reaction in the mother.

Blood stored in the liquid state has a maximum shelf-life of six weeks. Therefore, if only one unit (pint) is needed, it should be donated less than six weeks before the expected delivery date. It is best not to donate sooner than one week before delivery. If more blood is needed than can be safely donated during the last six weeks of pregnancy, this may be donated earlier in pregnancy (around twenty weeks), and frozen for later use. Freezing entails additional cost.

DIRECTED/DESIGNATED DONATION FROM THE FATHER OF THE INFANT

Generally speaking, husbands may donate blood for their wives provided that their red cells are compatible in the major ABO and Rh types. There are many other blood types ("minor" antigens) that usually do not have to be matched because transfusion of blood containing one of these antigens to a person lacking this antigen rarely causes antibodies in the patient. When antibodies do develop they do not appear for several months. By this time the transfused red cells have disappeared and therefore they escape damage by the antibody.

For a woman who plans to have pregnancies in the future, receiving blood from the father (or a paternal relative) poses a small increased risk for the infants of these pregnancies. If, after transfusion, the woman develops an antibody to an antigen on the father's red cells, and a subsequent fetus inherits the father's red cell antigen, the antibody from the mother may enter the bloodstream of the fetus causing destruction of the fetal red cells. This may cause serious anemia in the fetus and excessive jaundice in the infant after birth. These conditions are treated with special blood transfusions, using red cells that lack the particular offending antigen. For women who are unable to make an autologous donation, the decision to select her husband as a donor should take this risk under consideration.

Reference:

Kanter MH and Hodge SE. Risk of hemolytic disease of the newborn as a result of directed donation from relatives. Transfusion 1989; 29: 620-625.