The hormones that are produced only during pregnancy are human Placental Lactogen (hPL), human Chorionic Gonadotrophin (hCG) and relaxin. hCG Promotes maintenance of the corpus luteum during the beginning of pregnancy. It is used for testing pregnancy. hPL Produced by placenta facilitates the energy supply of the foetus by modifying metabolic state of the mother during pregnancy. Relaxin Its role is to relax the joints, in the pelvis so, to make a room for the baby to pass through the birth canal.