Missed pills: frequency, reasons, consequences and solutions.

OBJECTIVES: Oral hormonal contraception is an effective contraceptive method as long as regular daily intake is maintained. However, a daily routine is a constraint for many women and can lead to missed pills, pill discontinuation and/or unintended pregnancy. This article describes the frequency of inconsistent use, the consequences, the risk factors and the possible solutions. METHODS: The article comprises a narrative review of the literature. RESULTS: Forgetting one to three pills per cycle is a frequent problem among 15-51% of users, generally adolescents. The reasons for this are age, inability to establish a routine, pill unavailability, side effects, loss of motivation and lack of involvement in the initial decision to use oral contraceptives. The consequences are 'escape ovulations' and, possibly, unintended pregnancy. Solutions are either to use a long-acting method or, for women who prefer to take oral contraceptives, use a continuous or long-cycle regimen to reduce the risks of follicular development and thus the likelihood of ovulation and unintended pregnancy. A progestogen with a long half-life can increase ovarian suppression. CONCLUSIONS: For women deciding to use oral contraceptives, a shortened or eliminated hormone-free interval and a progestogen with a long half-life may be an option to reduce the negative consequences of missed oral contraceptive pills.

The effect of deliberate non-adherence to a norgestrel progestin-only pill: A randomized, crossover study.

OBJECTIVES: To estimate the effects on cervical mucus, ovarian activity and theoretical contraceptive protection of a 6-hour delay and of missing one norgestrel 0.075 mg progestogen-only pill. STUDY DESIGN: In a prospective, two-site, randomized, crossover study, healthy women aged 18 to 35 with BMI <32.0 kg/m² and regular ovulatory cycles completed a baseline 28-day cycle with correct daily pill use followed by two intervention cycles in which, around mid-cycle, one pill was taken 6 hours late or missed completely. We undertook ovarian ultrasonography, estradiol and progesterone measurement, and cervical mucus assessments every 3 to 4 days (daily around the time of the incorrect use) and based the theoretical contraceptive protection score on ovarian activity status, cervical mucus and their temporal relationship. RESULTS: Of 91 potential participants screened, 52 started the study and 46 provided complete data for each intervention cycle. Fourteen participants (30%) ovulated in each of the two intervention cycles, with four during the delayed pill cycle and two during the missed pill cycle having an abnormal luteal phase. Seven participants in the delayed pill cycle, and six with a missed pill had elevated cervical mucus scores temporally associated with the intervention. However only two women, one in the delayed pill cycle and one in the missed pill cycle, had cervical mucus scores in the range considered favorable for fertility. CONCLUSIONS: Delayed or missed intake of a single norgestrel 0.075 mg progestogen-only pill appears to have little effect on theoretical contraceptive efficacy. IMPLICATIONS: This biomedical study suggests that taking a norgestrel 0.075mg progestogen-only pill 6 hours late or missing one pill have little effect on ovarian activity or cervical mucus and may not jeopardize contraceptive efficacy. Correlation with typical use outcomes is necessary to confirm pregnancy risk with delayed or missed norgestrel intake.

Assessing the Pregnancy Protective Impact of Scheduled Nonadherence to a Novel Progestin-Only Pill: Protocol for a Prospective, Multicenter, Randomized, Crossover Study.

BACKGROUND: Progestin-only contraceptive pills (POP) are commonly reserved for women with medical comorbidities but in actuality, POPs can be safely used by anyone wanting to prevent pregnancy. This wide safety profile makes them an ideal candidate for being available over the counter without a prescription, but adherence issues may be more common with over-the-counter use. We need a better understanding of the ability of POPs to prevent pregnancy when adherence issues occur in the form of a missed or delayed pill. OBJECTIVE: This study aims to determine cervical mucus characteristics following a 6-hour delayed pill intake or after one missed pill as compared to typical daily use of norgestrel 75 mcg. METHODS: This prospective, multicenter, randomized, crossover study assesses the effect of norgestrel 75 mcg (Opill) on cervical mucus and ovarian activity during reported compliant daily use, after a 6-hour delayed intake mid cycle, and after a mid-cycle missed pill. Subject participation will last approximately 4.5 months. We will recruit at 2 US sites: Oregon Health & Science University, Portland, Oregon and University of California Davis Health, Sacramento, California. Reproductive-aged subjects with regular menstrual cycles (21-35 days), BMI <32 kg/m2, and proven ovulation (screening luteal phase progesterone >3 ng/mL [>10 nmol/L]) are eligible to enroll. Participants cannot be at risk for pregnancy during the study period and not use other hormonal methods. Norgestrel 75 mcg will be taken at the same time daily except for one day in each of treatment periods 2 and 3, when the pill will be taken either 6 hours late (delayed pill) or omitted completely (missed pill). Every 3-4 days, we will monitor subjects for follicular activity with transvaginal ultrasound (TVUS) examination, cervical mucus, and blood sampling for ovarian hormones and gonadotropins. Subjects will undergo serial cervical mucus sampling on the days with missed and delayed pill intake at 8 hours after pill intake on the day before the delayed or missed pill, 3 hours following the scheduled time of pill intake if intake was delayed, 6 hours after the scheduled time if intake was omitted, and on the next day 30 minutes before the time of scheduled pill intake. The primary objective of the study is to determine the effect of a delayed or omitted pill intake on cervical mucus characteristics based on a modified Insler score compared to reported daily use. RESULTS: Our protocol was successfully approved by a central institutional review board (Advarra, Columbia, MD), received ethical approval on March 23, 2018, and was registered with ClinicalTrials.gov (NCT03585712). As of January 2020, the study completed enrollment of 52 subjects. Analyses are pending. CONCLUSIONS: Our protocol was approved by a central review board, and study procedures were successfully executed with completed proposed enrollment. TRIAL REGISTRATION: ClinicalTrials.gov NCT03585712; https://clinicaltrials.gov/ct2/show/NCT03585712. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/29208.