['To assess the contraceptive effectiveness, safety, and potential health benefits of nomegestrol acetate contraceptive implant use by women with homozygous sickle cell disease (hemoglobin SS).', 'This was a prospective observation before and after insertion of nomegestrol acetate of 20 women with sickle cell disease (test group) compared with 10 women with similar sociodemographic backgrounds. Changes in hematologic and biochemical parameters and symptoms of sickle cell crisis were measured during 12 months of observation.', 'After use of nomegestrol acetate for 1 to 9 months, the women in the test group had symptomatic improvement, with no crisis that required hospitalization and no deaths. Sickle cell symptoms persisted in the women in the control group, with 1 recorded death. Increases in F-cell and fetal hemoglobin parallel the observed clinical improvement in the treated women. There were no adverse hematologic or biochemical changes associated with the use of nomegestrol acetate implants.'] Do nomegestrol acetate contraceptive implant use by women with sickle cell disease?