Effect of subdermal levonorgestrel contraceptive implants, Norplant, on liver functions

Forty-seven normal health women were studied longitudinally for changes in liver functions during the use of the levonorgestrel contraceptive implant system, NORPLANT. Samples were collected before insertion of the implants and after one, three and six months of use. The enzymes studied were the transaminases (SGOT and SGPT), alkaline phosphatase and gamma-glutamyl transferase. Serum bilirubin and bile acid levels were also measured. The protein synthetic function of the liver was tested by estimation of total proteins, albumin, transferrin, hemopexin, ceruloplasmin and haptoglobin. The three main immunoglobulins, G, M and A, were also measured. There were no significant changes in the liver enzymes after NORPLANT use. Serum bilirubin and bile acid concentrations showed rises in the first month of use which ameliorated in subsequent months. Serum albumin was transiently increased during the first and third months. Ceruloplasmin decreased significantly at the sixth month. The concentrations of total serum proteins and the other individual proteins showed no significant change. The results point to safety of NORPLANT implant use, as regards hepatic functions.