Anti-G in a pregnant patient

BACKGROUND: Anti-G is a red cell (RBC) antibody of the Rh system. It has be en described in pregnant women only in association with anti-D or anti-G; t herefore, the ability of this antibody alone to cause hemolytic disease of the newborn is uncertain. One case in which this antibody caused no clinica l sequelae is reported. CASE REPORT: The patient was a 35-year-old primigravida with type O, D-, C- , E-, c+ RBCs who was given 4 units of type O, D- allogeneic RBCs and 2 uni ts of autologous RBCs 2 years antepartum. She was found to have anti-D and anti-C by an outside laboratory as part of a routine prenatal work-up. Furt her evaluation by our laboratory revealed the presence of anti-G and possib le anti-C without anti-D Titers at 22 weeks' gestation were 64 against r'r RBCs and 16 against R2R2 RBCs; these remained unchanged throughout the preg nancy. Amniocentesis performed at Weeks 28 and 32 showed no evidence of hem olytic disease of the newborn. A healthy 3.3-kg infant was delivered at 36 weeks' gestation. Prophylactic Rh immune globulin was administered antepart um and postpartum. The infant's RBCs were type O, D+, c+ C-, E-, and the di rect antiglobulin test was positive. An acid eluate prepared from the baby' s RBCs revealed anti-G. The total bilirubin was 5.5 mg per dL at birth, and the hematocrit was 66 percent. Total bilirubin peaked on Day 5 at 11.9 mg per dL, and no therapeutic intervention was required. CONCLUSIONS: Anti-G alone caused little if any fetal or neonatal hemolysis in this case. Although further study is needed, invasive fetal monitoring m ay be unnecessary if anti-G is the sole cause of fetomaternal RBC incompati bility.