2 Collect one unit of blood from the mother. Centrifuge the whole
blood and remove as much plasma as possible. Resuspend her RBCs in group AB
3 Use fresh donor blood that possesses the antigen and is
(b) Incompatible blood has been used with success in many cases,
and one should not hesitate to use it if no compatible blood is available, the mother's
donor status is questionable, and the clinical situation is urgent.
2-20. RhO(D) IMMUNE GLOBULIN (HUMAN)-RhIG
a. Experience has shown that the routine administration of RhIG to
nonimmunized RhO-mothers who deliver Rh-positive babies is an effective means of
preventing Rh-alloimmunization. Candidates for this prophylaxis are mothers who are
Rh-negative and DU-negative, have no detectable anti-RhO(D) antibody, and have an
Rh-positive, or DU-positive newborn.
b. Since Rh antigens have been found on fetal RBCs quite early during
gestation, all Rh-negative women who have abortions are candidates, unless the father
or fetus is known to be Rh-negative.
c. The following women are not RhIG candidates:
RhO-negative women who deliver Rh-negative babies.
(2) RhO-negative women whose serum contains anti-RhO(D), RhO(D)
negative women who deliver Rh-positive babies and whose serum contains other
unexpected antibodies (for example, anti-KelI) are candidates.
RhO-positive or DU-positive women.
d. Administration of RhIG is indicated, but sometimes inadvertantly omitted after
several common events such as amniocentesis, antepartum hemorrhage, or ectopic
(1) If pregnancy in an Rh-negative woman terminates before 13-weeks
gestation, a dose of 50 ug is adequate to cover the small fetal blood volume during the
first trimester. From 13 weeks until term, the standard 300 ug dose should be given.
(2) Since fetomaternal hemorrhage may accompany amniocentesis, the
procedure can cause Rh immunization. The Rh-negative woman who has
amniocentesis at 16 to 18 weeks for genetic analysis should receive a 300 ug dose of
PhlG. A second dose should be given 12 weeks later, or at 28 weeks gestation, and a
third dose given after delivery if the baby is Rh-positive. Amniocentesis performed in
the second or third trimester of pregnancy on the non-immunized Rh-negative woman