Patterns of contraceptive side-effect variation: Assessing medical and lifestyle factors associated with side-effects among those using hormonal contraception in the United Kingdom.

INTRODUCTION

Contraceptive counselling typically employs a one size fits all approach and little is understood about variation in experiences of contraceptive side-effects and their drivers. This study set out to identify lifestyle and medical factors associated with experiencing side-effects when using hormonal contraception.

STUDY

DESIGN

We conducted a retrospective case-control study among users of four hormonal contraceptive methods (within the past 10 years) in the United Kingdom. We defined cases as those who discontinued a contraceptive method due to side-effects compared to controls who experienced no side-effects with that respective contraceptive method. We described the prevalence and severity of different side-effect symptoms and examined participant characteristics for associations with being a case versus control using minimally-adjusted multivariable logistic regression.

RESULTS

Of 1133 individuals, 796 were cases and 337 were controls. Mood disorders were the most commonly reported side-effect among those that had discontinuaed a contraceptive method due to side-effects. We found that reporting premenstrual syndrome symptoms when not using contraception was associated with higher odds of having discontinued a combined oral contraceptive pill or minipill due to side-effects (aOR: 2.5, CI 95%: 1.7-3.6, FDR < 0.001; aOR: 2.3, 95% CI: 1.5-3.8, FDR = 0.02 respectively). However, a history of premenstrual syndrome did not show evidence of an association with discontinuation of the hormonal intrauterine device. Individuals reporting anxiety or mood disorders before contraceptive use also had increased odds of having discontinued due to side-effects among combined oral contraceptive users.

CONCLUSION

Individuals with certain pre-existing gynaecological or mental health symptoms may be more likely to experience side-effects whilst using hormonal contraceptive methods that lead to discontinuation. As such, these individuals may require counselling to reflect such risk or extra support to manage contraceptive-related side effects and facilitate switching if desired.