The influence of a low-dose combined oral contraceptive on menstrual blood loss and iron status

Abstract

The influence of a low-dose combined oral contraceptive (ethinyl estradiol 30 μg + desogestrel 0.15 mg) on menstrual blood loss (MBL) was evaluated in 20 healthy, young women. MBL prior to commencing oral contraception was 60.2 ± 5.6 ml (range 22–116 ml), and decreased (p < 0.001) to 36.5 ± 5.2 ml (range 7–80 ml) and 33.7 ± 4.1 ml (range 5–70 ml) after 3 and 6 months' oral contraceptive medication, respectively. The reduction in MBL during oral contraception was most apparent during the first two days of menstruation. Five women had an MBL > 80 ml prior to commencing oral contraceptive medication. In all of these women, MBL during the 6th menstrual period after commencing oral contraception was < 80 ml. All the women included in this study had a normal blood hemoglobin concentration, hematocrit and erythrocyte indices and there were no significant changes in these variables during the course of the study. Serum ferritin concentration prior to commencing oral contraception was 44.2 ± 9.0 μg/l and was largely unchanged after 6 months' oral contraception (39.7 ± 6.3 μg/l). On admission to the study, two women had a serum ferritin < 10 μg/l, indicative of low iron stores. Both these women had an MBL > 80 ml at the baseline assessment. Serum ferritin concentration increased during oral contraceptive medication in both women (from 8.5 μg/l to 12.0 μg/l and from 5.4 μg/l to 6.8 μg/l, respectively).The duration of menstruation (p < 0.01) and the number of women suffering from dysmenorrhea (p < 0.05) was reduced during oral contraception.