Mariette X, et al. - The goal of this investigation was to assess placental transfer of certolizumab pegol (CZP), an Fc-free anti-tumour necrosis factor drug, from CZP-treated pregnant women to their infants. A lack of in utero foetal exposure during the third trimester was suggested by the observed no to minimal placental transfer of CZP from mothers to infants. When considered necessary, continuation of CZP treatment during pregnancy was supported.