A study on placental transfer of diclofenac in first trimester of human pregnancy

Diclofenac is a commonly used non-steroidal anti-inflammatory drug in women of reproductive age. It has teratogenic effects in animals. The aim of this study was to investigate the placental transfer of diclofenac in the first trimester of human pregnancy. Thirty patients undergoing surgical termination of pregnancy between 8 and 12 weeks gestation were given two doses of diclofenac before the procedure. Corresponding samples of maternal serum, amniotic fluid, coelomic fluid and fetal tissue were analysed by high-performance liquid chromatography. Diclofenac was detectable in all fetal tissue samples, with a concentration similar to that found in maternal venous samples. However, diclofenac was detectable in only 56.7 and 23.3% of the coelomic and amniotic fluid samples respectively, and the highest concentration attained was 80 and 5% of the maternal concentration respectively. In summary, we confirmed that diclofenac crosses the human placenta readily during the first trimester. Further studies are required to investigate the potential teratogenic effect of diclofenac in human embryos.