These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Effect of levonorgestrel contraceptive implants, Norplant, on blood coagulation.
    Author: Shaaban MM, Elwan SI, el-Kabsh MY, Farghaly SA, Thabet N.
    Journal: Contraception; 1984 Nov; 30(5):421-30. PubMed ID: 6440738.
    Abstract:
    A longitudinal study of coagulation parameters was carried out on 47 women using the levonorgestrel subdermal implants, NORPLANT. The study comprised measurement of platelet count, prothrombin time, thrombin time, partial thromboplastin time with kaolin, clotting factors I, II, V and VI through XIII, plasminogen, antithrombin III (AT III), alpha 1 antitrypsin, alpha 2 macroglobulin and fibrinogen degradation products. The tests were done at admission and after one, three and six months of NORPLANT use. Parallel and similar studies were done on two groups of oral contraceptive users; the first group used a pill containing 1 mg norethisterone and 50 micrograms mestranol, and the second a pill consisting of 150 micrograms levonorgestrel and 30 micrograms ethinylestradiol. Results from this ongoing study have indicated that women using NORPLANT implants evidenced lack of effects on most of the parameters tested except for factor VII activity which was increased and AT III concentration which was decreased after six months of use. The combined pill users evidenced marked changes in the platelet count, the screening tests and in most of the coagulation-promoting factors; the changes were apparent after three months of use and became more pronounced after six months. The results demonstrate, with marked contrast, that the implants had less pronounced effects on the blood coagulation system than did the combined pills used in this study. The effect of Norplant, a subdermal contraceptive implant containing levonorgestrel, on blood coagulation factors was investigated in 47 healthy women. Coagulation parameters were also measured in 55 subjects who were taking combination type oral contraceptives (OCs) (either a pill containing 1 mg norethisterone and 50 mcg mestranol or a preparation containing 150 mcg levonorgestrel and 30 mcg ethinyl estradiol). Blood sampling was carried out at admission and after 1, 3, and 6 months of contraceptive use. Parameters measured included platelet count, prothrombin time, thrombin time, partial thromboplastin time with kaolin, clotting factors I, II, V, and VI-XIII, plasminogen, antithrombin III, alpha 1 antitrypsin, alpha 2 macroglobulin, and fibrinogen degradation products. Norplant users showed a lack of effect on the factors tested, except for factor VII activity, which was increased, and antithrombin III concentration, which was decreased after 3 months of use. In contrast, the combined OC users evidenced marked changes in platelet count, the screening tests, and most coagulation promoting factors. These changes became more pronounced after 6 months. Women taking the levonorgestrel-ethinyl estradiol OC evidenced less pronounced changes in some coagulation parameters than those taking the norethisterone-mestranol preparation; however, the high dropout rate among OC users limits the conclusions that can be drawn from these results. These results point to a relative lack of effect of Norplant implants on the blood coagulation-fibrinolytic system, presumably due to the absence of estrogen and the low dose of progestogen delivered to the body.
    [Abstract] [Full Text] [Related] [New Search]