An unintended pregnancy can have significant effects on a patient with MS, particularly if she has uncontrolled MS. Family planning is an important part of managing your MS, and there are many available birth control methods to assist with this. Sterilization and long-acting reversible contraceptives (implants and intrauterine devices [IUDs]) result in less than 1 pregnancy per 100 women. Long-acting reversible contraceptives are encouraged as a first-line option for most women (including those with MS). They have a high satisfaction rate and are effective for several years before they must be replaced. Hormonal injections, pills, patch, and vaginal ring are not quite as effective, resulting in an average of 5 pregnancies per 100 women. The rhythm method, withdrawal, spermicides, sponges, diaphragms, and male and female condoms are the least effective of these methods, resulting in more than 15 pregnancies in 100 women.

OBJECTIVE:To provide evidence-based guidance for women and their health care providers on the management of missed or delayed hormonal contraceptive doses in order to prevent unintended pregnancy.EVIDENCE:Medline, PubMed, and the Cochrane Database were searched for articles published in English, from 1974 to 2007, about hormonal contraceptive methods that are available in Canada and that may be missed or delayed. Relevant publications and position papers from appropriate reproductive health and family planning organizations were also reviewed. The quality of evidence is rated using the criteria developed by the Canadian Task Force on Preventive Health Care.BENEFITS, HARMS, AND COSTS:This committee opinion will help health care providers offer clear information to women who have not been adherent in using hormonal contraception with the purpose of preventing unintended pregnancy.SPONSORS:The Society of Obstetricians and Gynaecologists of Canada. SUMMARY STATEMENTS: 1. Instructions for what women should do when they miss hormonal contraception have been complex and women do not understand them correctly. (I) 2. The highest risk of ovulation occurs when the hormone-free interval is prolonged for more than seven days, either by delaying the start of combined hormonal contraceptives or by missing active hormone doses during the first or third weeks of combined oral contraceptives. (II) Ovulation rarely occurs after seven consecutive days of combined oral contraceptive use. (II) RECOMMENDATIONS: 1. Health care providers should give clear, simple instructions, both written and oral, on missed hormonal contraceptive pills as part of contraceptive counselling. (III-A) 2. Health care providers should provide women with telephone/electronic resources for reference in the event of missed or delayed hormonal contraceptives. (III-A) 3. In order to avoid an increased risk of unintended pregnancy, the hormone-free interval should not exceed seven days in combined hormonal contraceptive users. (II-A) 4. Back-up contraception should be used after one missed dose in the first week of hormones until seven consecutive days of correct hormone use are established. In the case of missed combined hormonal contraceptives in the second or third week of hormones, the hormone-free interval should be eliminated for that cycle. (III-A) 5. Emergency contraception and back-up contraception may be required in some instances of missed hormonal contraceptives, in particular when the hormone-free interval has been extended for more than seven days. (III-A) 6. Back-up contraception should be used when three or more consecutive doses/days of combined hormonal contraceptives are missed in the second and third week until seven consecutive days of correct hormone use are established. For practical reasons, the scheduled hormone-free interval should be eliminated in these cases. (II-A) 7. Emergency contraception is rarely indicated for missed combined hormonal contraceptives in the second or third week of the cycle unless there are repeated omissions or failure to institute back-up contraception after the missed doses. In cases of repeated omissions of combined hormonal contraceptives, emergency contraception may be required, and back-up contraception should be used. Health care professionals should counsel women in these situations on alternative methods of contraception that do not demand such stringent compliance. (III-A).