Except for allergy to a particular component, no conditions in the US MEC contraindicate hormonal EC methods. With progestin-only regimens, levonorgestrel is taken as a single, onetime 1.5-mg dose (Arowojolu, 2002). his is now recommended instead of two 0.75-mg doses separated by 12 or 24 hours (Ngai, 2005). Dosing begins ideally within 72 hours of unprotected coitus but may be given up to 120 hours. Notably, the singledose regimen is available over-the-counter without a prescription to all reproductive-aged women (Food and Drug Administration, 2013,r2015a).
One progesterone-receptor modulator currently available for EC is ulipristal acetate and is marketed as Ela. It is taken as a single 30-mg tablet up to 120 hours after unprotected intercourse (Brache, 2010; Watson, 2010).
Also known as the Yuzpe method, this older EC method provides a minimum of 100 jLg of ethinyl estradiol and 0.5 mg of levonorgestrel in each of two doses. As shown in Table 38-3, a suicient dose may be achieved by two or more pills. he first dose is taken ideally within 72 hours of intercourse but may be given up to 120 hours. The initial dose is followed 12 hours later by a second equivalent dose.
The major mechanism with all hormonal regimens is inhibition or delay of ovulation. Of oral methods, failure rates are lowest with ulipristal (1 to 2 percent) and greatest with the Yuzpe method (2 to 3.5 percent) (Cleland, 2014). IfEC fails to prevent pregnancy or is mistimed, no associations with major congenital malformation or pregnancy complications have been noted with these hormonal methods (Jatlaoui, 2016; Levy, 2014).
With EC administration, nausea and vomiting can be an important side efect (American College of Obstetricians and Gynecologists, 2015b; Gemzell-Danielsson, 2013). Accordingly, an oral antiemetic may be prescribed at least 1 hour before each dose (Rodriguez, 2013). If a woman vomits within 2 hours of a dose, the dose is repeated.
For women who are candidates, Cu-IUD insertion is the most efective emergency contraceptive method and provides an efective 10-year method of contraception (Cheng, 2012). If an IUD is placed up to 5 days after unprotected coitus, the failure rate approximates only 0.1 percent (Cleland, 2012; Wu, 2010).
For mothers who are nursing exclusively, ovulation during the irst 10 weeks after delivery is unlikely. Nursing, however, is not a reliable method of family planning for women whose infants are on a daytime-only feeding schedule. Moreover, waiting for first menses involves a risk of pregnancy, because ovulation usually antedates menstruation. Certainly, after the first menses, contraception is essential unless the woman desires pregnancy.
As shown in Table 38-2, all methods may be suitable for nursing mothers after the initial weeks, during which thromboembolism risks are still great. With all hormonal methods, very small quantities are excreted in breast milk, but no adverse efects on infants have been reported (Phillips, 2015; World Health Organization, 1988). Although not robust, some older studies link decreased infant weight gain or milk volume with early initiation of combination oral contraceptives before 6 weeks postpartum (Lopez, 2015c; Tepper, 2016a).