Continuous Use of Etanercept During Pregnancy Does Not Affect TNF-Alpha Levels in Umbilical Cord Blood

TNF-alpha-targeted therapies during pregnancy is a topic of interest in rheumatology. Etanercept (ETN) is expected to have lower transplacental transfer, however, clinical evidence is lacking on the usefulness and safeness of continuing etanercept throughout pregnancy. We here described the first reported case of relapsing polychondritis where continuous use of ETN throughout pregnancy was required. The patient was a pregnant Japanese woman who presented with bilateral ear cartilage redness, swelling, saddle nose and severe subglottic oedema. Due to severe systemic and life-threatened disease, we decided to continue using ETN throughout pregnancy and resulted in successful vaginal delivery. The treatment with ETN was successful and TNF-alpha levels in umbilical cord blood were not affected. The infant did not have any signs of chondritis although levels of anti-type 2 collagen antibodies in maternal and umbilical cord blood were similar, suggesting that anti-type 2 collagen antibodies crossed the placenta. This case is an important clinical experience that strengthens the safety to continue ETN during the entire pregnancy if necessary.