Asma Rashid, Latif Aftab, Tayyab M, Ahira Tasneem, Naseer Chaudhry.
Hormonal Contraception and risk of Thromboembolism.
Pak Postgrad Med J Jan ;13(3):112-3.

Platelet hyperaggregation in women on hormonal contraception was thought to be an initial disorder leading to thromboembolism. The present study was conducted on subjects taking hormonal contraceptive drugs. Comparison between oral (Group B) and injectable preparations (Group C) was carried out with controls (Group A). Hyperactivity of platelet was seen all those women using ADP and collagen as agonist. Statistical difference between group A & B was significantly high (P<0.001) while it was significant (P<0.05) between group A & C and B & C. So hyperaggregibility of platelet was more in oral contraceptive users as compared to injectable drugs due to direct effect of estrogen on platelet functional activity, progesterone on the other hand, by changing the lipid levels, altered platelet activity.

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