Abstract 730: Pregnancy Outcome after Exposure to Biologics: Results from the German Biologics Register RABBIT
Authors:
A. Strangfeld, J. Listing, R. Rau, M. Schneider, F. Hierse, A. Krause, M. Backhaus, A. Zink
Methods
The RABBIT registry was used to explore pregnancy outcomes in RA patients. RA patients identified as having been pregnant or discontinuing therapy for plan of conception were interviewed for confirmation of exposure and determination of pregnancy and delivery outcome. Subjects were compared according to whether mothers discontinued TNF inhibitors prior to conception or whether TNF inhibitors were continued until confirmation of pregnancy.
Results
Among 4,104 females enrolled in the registry, 755 were within reproductive age (defined as < 43 years). Among 545 women of reproductive age treated with biologics, there were 37 in 29 women who received TNF inhibitors prior to conception. Of these, 22 pregnancies (59%) occurred in women who continued TNF inhibitors up to the confirmation of pregnancy. Two pregnancies were exposed to methotrexate or leflunomide (in addition to biologics) up to the confirmation of pregnancy. Mean maternal age was comparable between the two comparison groups (approximately 33 years). There was no significant difference in mean birth weight, preterm delivery rate, or miscarriage between the two groups. No congenital malformations were encountered.
Conclusions
Within a small sample, there was no difference in pregnancy outcomes between women discontinuing TNF inhibitors prior to conception and those who continued up to the time that pregnancy was confirmed.
Editorial Comment
This study highlights the large number of patients required to study pregnancy outcomes in RA patients. This is related to a number of factors, including that women often have had children prior to their RA diagnosis and studies suggest that women chose to have fewer children after diagnosis than they would have if they had not been diagnosed with RA. Even so, most practitioners are faced on a regular basis with the dilemma of whether to continue TNF inhibitors through conception. Despite the small number of pregnancies, the results of this investigation are reassuring and support what many rheumatologists are doing in practice. However, more research is needed with larger numbers of patients to identify whether the risk for less frequent but more severe outcomes are increased. It is important to recognize that there are currently no data addressing whether TNF inhibitors can be safely continued throughout pregnancy, and prudence warrants discontinuation at the latest at the time of pregnancy confirmation. Restarting for severely active disease during pregnancy (thankfully occurring in a minority of pregnant RA patients) must be left to the discretion of the patient and treating physician with acknowledgment of the current deficiencies in knowledge.
