Menstrual problems and contraception in women of reproductive age receiving oral anticoagulation

Oral anticoagulation is associated with increased bleeding complications. The aim of this study was to assess the changes in menstrual loss and pattern in women taking anticoagulant treatment.

Women on oral anticoagulant (OA) treatment at the Royal Free Hospital were interviewed and completed a questionnaire about their menstrual cycle before and after commencing oral anticoagulation treatment. They were then asked to complete a pictorial bleeding assessment chart (PBAC) during their next menstrual bleeding episode.

Fifty-three women between the ages of 20 and 50 years participated in the study. Of these, 47 women completed a PBAC. The mean duration of menstruation increased from 5 days before starting OA therapy to 7 days after the commencement of treatment. Thirty-one (66%) of the 47 women who completed the PBAC had a score that was greater than 100. The number of women who experienced flooding or clots during menstruation and intermenstrual or postcoital bleeding also increased. In total, 29 (54.7%) women changed their method of contraception during OA treatment. Seventeen women who did not want to become pregnant were not using contraception, including 10 women who were on hormonal contraception prior to starting anticoagulant therapy.

Women of reproductive age experience heavy and prolonged menstrual bleeding whilst on OA therapy. Women of reproductive age on OA therapy should be monitored for menstrual disorders to ensure that prompt and appropriate treatment is instituted. Advice about appropriate contraception should also be part of the medical care provided for these women. Barrier contraception, sterilization and progestin-only contraception are all suitable methods of contraception in this patient group.