A Cochrane review «Combined oral contraceptive pill for primary dysmenorrhoea»1 «Schroll JB, Black AY, Farquhar C et al. Combined o...»1 included 21 studies with a total of 3723 women; 11 studies compared different oral contraceptive pill (OCP) preparations with placebo and 8 compared different preparations with each other.
OCPs were better in pain relief than placebo (moderate reduction in pain; standardised mean difference [SMD] −0.58, 95% CI −0.74 to −0.41; I² = 28%; 6 RCTs, n=588). The data suggested that in women with a 28% chance of improvement in pain with placebo or no treatment, the improvement in women using combined OCP will be between 37% and 60%. OCPs increased the risk of any adverse events (RR 1.31, 95% CI 1.20 to 1.43; I² = 79%; 7 RCTs, n=1025).
Continuous use of OCPs reduced pain in women with dysmenorrhoea more effectively than the standard regimen (SMD −0.73, 95% CI −1.13 to 0.34; 2 RCTs, n=106 women). There was insufficient evidence to determine if there was a difference in pain improvement between ethinylestradiol 20 μg and ethinylestradiol 30 μg OCPs. There was little or no difference between third- and fourth-generation and first- and second-generation OCPs (RR 0.99, 95% CI 0.93 to 1.05; 1 RCT, n=178). The standard regimen of OCPs may slightly increase the risk of any adverse events over the continuous regimen.There were insufficient data to determine whether OCPs were more effective than NSAIDs for pain (only 1 trial, n=91).