Placebo‐controlled trial of active immunization with third party leukocytes in recurrent miscarriage

Abstract

OBJECTIVE: To investigate whether active immunization with third party leukocytes improves pregnancy outcome in women with unexplained recurrent miscarriages. DESIGN: A double-blind prospective placebo-randomized trial. PATIENTS: Sixty-six patients with unexplained recurrent miscarriages achieved pregnancy after having received active immunization or placebo. INTERVENTIONS: Among the patients who achieved pregnancy, 43 were immunized with third party leukocytes and 23 received autologous leukocytes. MAIN OUTCOME MEASURES: Frequency of new miscarriages in actively immunized women compared with placebo. RESULTS: In the total group of patients, 71% of the actively immunized patients had a successful pregnancy compared with 48% of the placebo treated patients (not significant, RR = 0.6; 95% confidence limits = 0.3-1.1). In a subgroup of patients with primary recurrent miscarriages the success rate was 76% compared with 38% in the placebo group (p < 0.02, RR = 0.4; 95% confidence limits = 0.2-0.9). In this subset of patients, median birthweight was also significantly higher in actively immunized patients than in placebo treated patients (3445 g versus 3000 g; p < 0.05). CONCLUSIONS: Active immunization did not provide any benefit in the overall group of women with recurrent miscarriages. However, among women with primary recurrent miscarriages it may improve outcome with respect to the number of livebirths and birthweight.