PIP: Clinical profile and toxicology studies on 4 women immunized with processed beta human chorionic gonadotropin conjugated to tetanus toxoid (Pr-beta-HCG-TT) are presented. The women responded to active isoimmunization by production of anti-hcg and anti-TT antibodies. The women were followed for 1 year with monthly clinical examinations including laboratory hepatic function tests, renal function tests, metabolic studies, endocrinal studies, and hematological studies. No abnormality was seen, indicating that active isoimmunization with Pr-beta-HCG-TT has no adverse or undesirable side effects in women of childbearing age.