Revision of the 'missed pill' rules.

In 2005, the Clinical Effectiveness Unit (CEU) of the then Faculty of Family Planning and Reproductive Health Care adopted the World Health Organization (WHO) ‘missed pills’ guidance (Figure 1).1 Many clinicians criticised this change2–5 as these new rules appeared to be complex and caused confusion at the grass roots level.6–8 There were also concerns that liberalising the ‘missed pills’ guidance (Box 1)9 would lead to additional unplanned pregnancies among pill-takers and did not support safer sex messages or the importance of correct and consistent pill-taking.2 3 5 Unfortunately the 2005 changes appeared to have been based on old papers since superseded.10–16 Even at that time there was evidence contradicting a relaxing of the rules.17–19 The CEU admitted they did not consider recently published evidence from 2003 and 2004,10 which was worrying as Pierson et al.19 demonstrated presumed ovulation in 13–19% of 30–35 μg triphasic pill-users following a 3-day dosing error thereby extending the pill-free interval. Since then further evidence has been published suggesting that hormone-free intervals of 7 or more days can result in breakthrough ovulations and a significant increase in pill failure.20–22 One of the arguments posed suggested that even though studies reported higher ovulation rates, failure had not been linked with the ‘pill-free’ interval10 and these women did not become pregnant. However, it should be pointed out that women taking part in these studies used abstinence or barrier methods when pills were missed. Studies exploring ovarian follicular activity when extending the hormonefree interval include small numbers of women and are not powered to detect wide individual variation.23 Authors of a systematic review in 2006 acknowledged that these studies also gave varied definitions of ‘ovulation’ and this inconsistency questions their methodology.23 Accurate detection of ovulation requires frequent and detailed endocrine and ultrasonic evaluation. The ‘missed pill’ guidance in combined hormonal contraceptives’ Summary of Product Characteristics leaflets is overcautious, particularly if pills are missed mid-packet (Box 1).9 In 2010, the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) recognised that there was a need to simplify these rules. The MHRA organised a meeting with representatives from a number of key UK organisations including the Faculty of Sexual and Reproductive Healthcare (FSRH), the FPA (Family Planning Association) and the pharmaceutical industry. The aim was to produce standardised guidance on the starting of combined hormonal contraceptives and on ‘missed pills’, emphasising the need for regular pill-taking and not ‘missing pills’ around the pill-free interval. The MRHA ‘24-hour missed pill advice’ (Box 2) is clear.24 No action needs to be taken until 24 hours or more has elapsed from the usual ‘pill-taking’ time. If this occurs, anywhere in the packet, the forgotten pill needs to be taken and the next pill when it is due – this may mean taking two pills in 1 day. No additional contraception is required. If two or more pills are forgotten (more than 48 hours late) only the last ‘forgotten’ pill is taken and the next pill taken at the usual time – this may mean taking two pills in 1 day. Additional contraception is needed for the next 7 days. If there are fewer than seven pills left in the pack, the pack should be finished and a new pack started the next day missing out the break. The ‘emergency contraception (EC)’ advice, however, is confusing. The MHRA suggest that only women “who have unprotected sex in the previous 7 days and have missed two or more pills in the first week of their pack” should seek advice about EC. What about those who have repeated unprotected sex from the start of the hormone-free interval? Clinical Director, Sexual Health Services, Newcastle Hospitals Community Health, New Croft Centre, Newcastle upon Tyne, UK