Papers And Originals

Oestrogen/Progestogen Oral Contraception and Blood Clotting: A Long-term Follow-up

Br Med J 1971; 4 doi: (Published 11 December 1971) Cite this as: Br Med J 1971;4:648
  1. L. Poller,
  2. Jean M. Thomson,
  3. Wendy Thomas


    In a long-term study of women taking the combined oestrogen/progestogen oral contraceptives Ortho-Novin and Norinyl-1 the follow-up has been continued for three years and four years respectively.

    Acceleration of both “intrinsic” and “extrinsic” clotting tests and of specific factor VII and X assays, reported previously at the nine-month stage, persisted throughout the period of study. Acceleration of Chandler's tube platelet aggregation and hypercoagulable thrombelastographic patterns were recorded. There was, however, no evidence of a cumulative effect after the first nine months.