Introduction Unprotected intercourse after oral emergency contraception (EC) significantly increases pregnancy risk. This underlies the importance of promptly starting effective, ongoing contraception – known as ‘quick starting’. However, theoretical concern exists that quick starting might interact with EC or hormonal contraception (HC) potentially causing adverse side effects.
Method A systematic review was conducted, evaluating quick starting HC after oral EC [levonorgestrel 1.5 mg (LNG) or ulipristal acetate 30 mg (UPA)]. PubMed, EMBASE, The Cochrane Library, ICTRP, ClinicalTrials.gov and relevant reference lists were searched in February 2016. A lack of comparable studies prevented meta-analysis.
Results Three randomised controlled trials were identified. Two biomedical studies suggested HC action was unaffected by quick starting after UPA; one study examined ovarian quiescence (OR 1.27; 95% CI 0.51–3.18) while taking combined oral contraception (COC). Another assessed cervical mucus impenetrability (OR 0.76; 95% CI 0.27–2.13) while taking progestogen-only pills (POP). Quick starting POP reduced the ability of UPA to delay ovulation (OR 0.04; 95% CI 0.01–0.37). Side effects (OR 1.22; 95% CI 0.48–3.12) and unscheduled bleeding (OR 0.53; 95% CI 0.16–1.81) were unaffected by quick starting COC after UPA. Another study reported higher self-reported contraceptive use at 8 weeks among women quick starting POP after LNG, compared with women given LNG alone (OR 6.73; 95% CI 2.14–21.20).
- emergency contraception
- quick start
- ulipristal acetate
- systematic review
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Contributors This study was undertaken as an undergraduate research project by LM, supervised by ZEC. LM produced and registered the protocol. LM and VW conducted the systematic literature search and assessed the included study quality. ZEC and SC reviewed and edited the drafts and final manuscript.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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