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.
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.
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).
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.