A dose comparison study of IVIG in postpartum relapsing-remitting multiple sclerosis.

Untreated patients with relapsing-remitting multiple sclerosis (RRMS) have an elevated risk of exacerbation in the first 3 months postpartum. Pregnant patients (n =173) with RRMS and with at least one relapse in the two years before pregnancy were enrolled in this multinational, multicentre, randomized double-blind clinical trial investigating different doses of intravenous immunoglobulin (IVIG) treatment in the 6 months postpartum. Group I (unloaded) received 150 mg/kg body weight (BW) IVIG on Day 1, then placebo infusions on Day 2 and Day 3. Group II (loaded) received 450, 300 and 150 mg/kg BW on Days 1, 2 and 3 respectively. Both groups then received 150 mg/kg BW five times in four-weekly intervals. The ratio of patients remaining relapse-free during the first 3 months postpartum did not differ significantly between both groups (81.5% in Group II versus 75.6% in Group I). The ratio of relapse-free patients was independent of dosage in the subgroup of patients breastfeeding for at least 3 months (89% in Group I versus 90% in Group II). The mean annualized relapse rate (ARR) after pregnancy did not show an increased risk for exacerbation, but returned to prepregnancy level within 3 months independent of dosage. The treatment was well tolerated.