***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Megestrol acetate given orally has been assessed in its effect on sickling in vitro . Per cent sickling rates were reduced by the drug compared to placebo . The results indicate the need for further assessing the clinical advantage of oral progestins in patients with sickle cell disease which may also be relevant to their use as contraceptives Forty-three homozygous ( SS ) female sickle cell anemic patients with a history of at least one painful crisis per month and desiring a reversible contraceptive were administered DMPA/3 months or Microgynon monthly . A third group of 16 surgically sterilized patients served as control . Patients were followed for 1 year to assess possible effects of the contraceptives on the patients ' painful crises . No changes were observed in any of the groups in the hematological parameters . At the end of the study , 70 % of the patients receiving DMPA were pain-free and only 16 % of those still reporting painful crises rated them as intense . Patients receiving Microgynon also had an amelioration of the painful crises , although at a lower rate ; after 12 months , 45.5 % still experienced some crises . Although less marked than in the other groups , 50.5 % of the control patients also reported an improvement of their painful crisis , which may be a result of closer medical care OBJECTIVE To assess the safety of Norplant contraceptive implant use by women with mild-moderate homozygous sickle cell disease ( HbSS ) . METHOD Prospect i ve observation of women pre- and post-insertion of Norplant  , with each woman serving as her own control . PARTICIPANTS 25 women 18 - 40 years of age who attended a hospital sickle cell clinic ; post-insertion data were available for 23 women . OUTCOME MEASURES Changes in hematologic parameters including PCV , MCV , reticulocytes , ISCs , HbF and bilirubin ; changes in biochemical parameters including HDL cholesterol , aspartate transaminase , alkaline phosphate , serum creatinine and serum albumin . RESULT With a mean follow-up of 12.4 months ( range 1 - 29 months ) , there were no clinical ly or statistically significant group or individual changes in the hematologic or biochemical parameters after Norplant insertion . CONCLUSION Norplant appears to be a safe and appropriate contraceptive for women with mild-moderate HbSS disease 
    Output:
    
Although data are limited , these studies suggest that progestogen-only contraceptives are safe for women with sickle cell anemia