Anti-D administration after spontaneous miscarriage for preventing Rhesus alloimmunisation

BACKGROUND: During pregnancy, a Rhesus-negative (Rh-negative) woman may develop antibodies if her fetus is Rh-positive, which can cause fetal morbidity or mortality in following pregnancies, if untreated.

OBJECTIVES: To assess the effects of administering anti-D immunoglobulin (Ig) after spontaneous miscarriage in a Rh-negative woman, with no anti-D antibodies.

SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 December 2012).

SELECTION CRITERIA: Randomised controlled trials (RCT) in Rh-negative women without antibodies who were given anti-D Ig following spontaneous miscarriage compared with no treatment or placebo treatment following spontaneous miscarriage as control.

DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion and trial quality. Two review authors extracted data and checked it for accuracy.

MAIN RESULTS: We included one RCT, involving 48 women who had a miscarriage between eight to 24 weeks of gestation. Of the 19 women in the treatment group, 14 had therapeutic dilatation & curettage (D&C) and five had spontaneous miscarriage; of the 29 women in the control group, 25 had therapeutic D&C and four had spontaneous miscarriage. The treatment group received 300 µg anti-D Ig intramuscular injection and were compared with a control group who received 1 cc homogenous gamma globulin placebo.This review's primary outcomes (development of a positive Kleihauer Betke test (a test that detects fetal cells in the maternal blood; and development of RhD alloimmunisation in a subsequent pregnancy) were not reported in the included study.Similarly, none of the review's secondary outcomes were reported in the included study: the need for increased surveillance for suspected fetal blood sampling and fetal transfusions in subsequent pregnancies, neonatal morbidity such as neonatal anaemia, jaundice, bilirubin encephalopathy, erythroblastosis, prematurity, hypoglycaemia (low blood sugar) in subsequent pregnancies, maternal adverse events of anti-D administration including anaphylactic reaction and blood-borne infections.The included study did report subsequent Rh-positive pregnancies in three women in the treatment group and six women in the control group. However, due to the small sample size, the study failed to show any difference in maternal sensitisation or development of Rh alloimmunisation in the subsequent pregnancies.

AUTHORS' CONCLUSIONS: There are insufficient data available to evaluate the practice of anti-D administration in an unsensitised Rh-negative mother after spontaneous miscarriage. Thus, until high-quality evidence becomes available, the practice of anti-D Immunoglobulin prophylaxis after spontaneous miscarriage for preventing Rh alloimmunisation cannot be generalised and should be based on the standard practice guidelines of each country.