An analysis from two identically designed randomized, placebo-controlled, multiple center studies conducted in Europe, Australia and North America assessed the effectiveness of combined oral contraceptive (COC with estradiol valerate plus dienogest) in reducing menstrual blood loss (MBL) in women with objectively confirmed heavy menstrual bleeding. Women aged ≥ 18 years were randomized to COC (n=220) or placebo (n=135) for 7 treatment cycles. At study end, the proportion of women successfully treated (MBL below 80 mL and ≥ 50% reduction in MBL) with COC and placebo were 63.6% and 11.9%, respectively; with 68.2% and 15.6% of women with MBL below 80 mL, and 70.0% and 17.0% with MBL reduction ≥ 50% (all p<.001).
A Cochrane review included only one small study (n=45). The study found no significant difference between groups treated with oral contraceptives, mefenamic acid, low dose danazol or naproxen.
Comment: The quality of evidence is downgraded by study quality (lack of blinding) and by imprecise results (limited study size for each comparison).
The combined contraceptive pill is both an effective contraceptive and effective treatment for menorrhagia when compared with other medical treatments. It is not, however, possible to expand upon this statement as there is a lack of good quality data, and the use of the contraceptive pill in this area has been insufficiently studied.