Effect of biologic disease-modifying anti-rheumatic drugs for patients with rheumatoid arthritis who hope to become mothers

Objectives: We examined the effect of biologic disease-modifying anti-rheumatic drugs on the time to pregnancy in patients with rheumatoid arthritis who hope to become mothers. Additionally, we evaluated adverse pregnancy outcomes and risk factors of these drugs.

Method: We retrospectively investigated 25 pregnancies of 19 patients who were taking disease-modifying anti-rheumatic drugs. In 15 pregnancies, patients continued biologic disease-modifying anti-rheumatic drugs until conception (group A). In 10 pregnancies, patients discontinued biologic disease-modifying anti-rheumatic drugs and conventional synthetic disease-modifying anti-rheumatic drugs at the time of planning to conceive (group B). We used tumor necrosis factor inhibitors (certolizumab pegol and etanercept) for group A patients.

Results: The mean time to pregnancy was shorter in group A than in group B (5.9 ± 3.8 vs 11.0 ± 6.5 months, P = 0.04). The mean birth weight of newborns was lighter in group B than in group A (2446.5 ± 352.4 vs 2969.4 ± 459.9 g, P = 0.007). There were no significant differences in the rates of preterm birth, light-for-date, and premature rupture of the membranes between the groups. In patients with preterm birth or light-for-date newborns, the mean dose of corticosteroids during pregnancy was significantly higher compared with that in those with full-term birth or non-light-for-date newborns (P = 0.02, P < 0.01, respectively).

Conclusions: In patients with rheumatoid arthritis who hope to conceive, continuing biologic disease-modifying anti-rheumatic drugs at the time of conception could shorten the time to pregnancy. Using biologic disease-modifying anti-rheumatic drugs before pregnancy does not affect abortion, preterm birth, light-for-date, and premature rupture of the membranes.