Table 10.4 Cost per Patient per Year of Contraceptive Methods a For every $1.00 spent on vasectomy, the amount shown would be spent on the method indicated. From Ashraf T, Arnold SB, Maxfield M. Cost effectiveness of levonorgestrel subdermal implants: comparison with other contraceptive methods available in the United States. J Reprod Med 1994;39:791–798, with permission.
Several contraceptive methods are as effective as sterilization, but are completely reversible. All have the important advantage of being “forgettable,” that is, little is required of the user after the method is begun, very much in contrast to methods like the condom that must be used with each act of intercourse, or the OC, which must be taken daily. These forgettable methods have pregnancy rates in typical use of less than 2 per 100 woman-years, are effective for at least 3 months without attention from the user, and are among the safest methods. They include the injectable progestins, depomedroxyprogesterone acetate (DMPA) and norethindrone enanthate, the etonogestrel and levonorgestrel subdermal implants, copper-bearing intrauterine devices such as the copper T380A and the levonorgestrel-releasing intrauterine system (9,10).
Coitus Interruptus Coitus interruptus is withdrawal of the penis from the vagina before ejaculation. This method, along with induced abortion and late marriage, is believed to account for most of the decline in fertility of preindustrial Europe (11). Coitus interruptus remains a very important means of fertility control in many countries. Eighty-five million couples are estimated to use the method worldwide, yet it has received little recent formal study. This method has obvious advantages: immediate availability and no cost. The penis must be completely withdrawn both from the vagina and from the external genitalia. Pregnancy has occurred from ejaculation on the female external genitalia without penetration. Coitus interruptus reduces transmission of human immunodeficiency virus (HIV) in mutually monogamous couples (12). Theoretically, some reduction of risk from other STDs would be expected, but this phenomenon apparently was not studied. Efficacy is estimated to range from 4 pregnancies per 100 women in the first year with perfect use to 27 per 100 with typical use (Table 10.2). Jones and colleagues offer a modern review of this practice and conclude that it likely is as effective as the condom (13).
Breastfeeding Breastfeeding can be used as a form of contraception and can be effective depending on individual variables. The use of contraception during lactation should take into consideration the women’s needs and the need to maintain lactation.
Ovulation is suppressed during lactation. The suckling of the infant elevates prolactin levels and reduces gonadotropin-releasing hormone (GnRH) from the hypothalamus, reducing luteinizing hormone (LH) release and thus inhibiting follicular maturation (14). Even with continued nursing, ovulation eventually returns but is unlikely before 6 months, especially if the woman is amenorrheic and is fully breastfeeding with no supplemental foods given to the infant (15). For maximum contraceptive reliability, feeding intervals should not exceed 4 hours during the day and 6 hours at night, and supplemental feeding should not exceed 5% to 10% of the total amount of feeding (16). Six-month pregnancy rates of 0.45% to 2.45% are reported for couples relying solely on this method (17). To prevent pregnancy, another method of contraception should be used from 6 months after birth or sooner if menstruation resumes. Breastfeeding reduces the mother’s lifetime risk of breast cancer (18).