Quick starting hormonal contraception after using oral emergency contraception: a systematic review

Abstract

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 – an evidence‐based practice guide

“…Recommendations are more complex following use of UPA given concerns that UPA may interact with other forms of hormonal contraceptive due to its role as a progesterone receptor modulator . A recent systematic review of commencing hormonal contraception following EC use identified limited studies on which to base treatment recommendations, but did find evidence to suggest that initiation within 5 days of UPA use may negatively impact on its ability to delay ovulation, exposing women to the same risk of pregnancy faced without use of EC . Therefore, if UPA is used then alternative hormonal contraception should not be commenced for 5 days, at which point an additional barrier method of contraception should be used until contraceptive cover is provided.…”