Background and aims SLE often affects women of childbearing age. Prednisone is safely used during pregnancy. Modified-release prednisone (MRP) is a treatment option, but no data exist regarding gestation: we aimed to compare its safety and effectiveness to the immediate release formulation (IRP) in SLE pregnancies.

Methods During a 5 year period, we enrolled 18 SLE female patients experiencing a pregnancy. Nine (cases), taking low-dose MRP (5 to 7.5 mg/daily) as a baseline treatment, were matched to 9 controls (same age and disease duration), taking the same prednisone dose in the IR formulation. Pregnancy outcome; SLEDAI/SLEPDAI; patient’s VAS and need of treatment changes were assessed at baseline, during pregnancy and at postpartum.

Results SLEDAI at baseline was 2±0.1 among MPR and 2±0.3 among IR women; SLEPDAI, 3±0.9 and 3±0.2 (both, p=ns). No major perinatal complications were detected. Preterm births, caesarean section rates, newborns weight and APGAR scores did not differ between the two subpopulations (all, p=ns). SLEDAI at postpartum was 3.8±0.6 in MRP subjects and 5.4±0.4 in IR (p<0.05). Patients VAS evaluation (MRP vs IR) was, respectively, 30±4 and 20±9 at baseline (p=ns);30±6 and 48±7 during pregnancy (p<0.05) and 31±3 and 52±9 at postpartum (p<0.05). Prednisone regimen changes (add-on strategy), the observed rates involved 1/9 (MRP) and 5/9 (IR) women (p<0.05).

Conclusions Among IR patients, activity was significantly higher during postpartum and treatment had to be increased. VAS was significantly different (higher among IR), both during pregnancy and postpartum. MRP seems to be as safe, but more effective, in comparison the IR, during pregnancy of SLE women.