Nearly half of all pregnancies in the United States are unintended1—a fact that is both astounding and unacceptable in an era of rapid advances in medical technology and pharmacology. The problem is not the result of too few contraceptive options, but rather of ineffective communication about acceptable options. Contraceptive counseling requires a delicate balancing of the needs of each patient with the efficacy, mechanism of action, risks, and benefits of each available method. One study suggests that adherence to contraceptive regimens improves when women are provided with comprehensive information in a respectful, patient-centered approach.2 Because both patient education and respect are foundations of the PA mission, we hold a pivotal role in enhancing contraception.
Influencing factors
In the contraceptive counseling session, try to elicit the reasons that might influence a patient to adhere to a particular method of contraception. Some of these factors include medical history, experience with contraception, partner support, convenience of use, protection against sexually transmitted diseases (STDs), effects on lifestyle, frequency of intercourse, desire for children in the future, and personal, religious, or cultural convictions. The ongoing cost of contraception is another factor to be discussed with the patient. Any provider who offers contraceptive counseling should be familiar with the cost of contraceptive options and assistance programs available in the area.
Because no form of contraception is guaranteed to prevent pregnancy, it is also important to assess how much 
risk a patient is willing accept that a pregnancy may occur. Contraceptive efficacy is measured as the number of women out of 100 who become pregnant unintentionally in the first year a method is used (see Figure 1). This definition is further divided into perfect use (women who report using the method consistently and correctly every time) and typical use (women who report occasional incorrect or inconsistent use). Examples of typical use include occasionally missing a daily pill or occasionally not using a diaphragm. The efficacy numbers generally quoted to patients are the typical use values.
Behavioral methods of contraception
Natural family planning/Fertility awareness methods (NFP/FAM) Some women may be unwilling to employ artificial contraceptive methods for personal, religious, or cultural reasons, preferring NFP or FAM. These approaches can be effective for a woman with regular menses and a partner committed to helping her make the method work. A woman can approximate her time of ovulation by maintaining a calendar of menses, noting changes in cervical mucus, and recording daily basal body temperatures. Near ovulation when fertilization will most likely occur, women may choose to abstain from intercourse (NFP) or use alternate methods such as withdrawal or condoms (FAM) to avoid pregnancy. Because of the variability in each woman's cycle and the discipline required for successful implementation, this method has an inherently high failure rate. Behavioral methods require detailed patient training in order to be effective; educational materials for patients and clinicians are available from the Institute for Reproductive Health at www.irh.org.
Withdrawal (coitus interruptus) This is another option for couples who choose not to use contraceptive devices or pharmacology. In this method the penis is withdrawn completely from the vagina before ejaculation occurs, in order to reduce the number of sperm introduced into the vagina. This method is highly dependent upon the man's cooperation and ability to predict ejaculation. Withdrawal does not require a barrier and thus does not protect from sexually transmitted infections.
Lactation infertility When a baby nurses, a maternal surge in prolactin inhibits ovulation. In most cases, a woman must provide at least 90% of the baby's feedings for this method to be effective. Lactation-induced amenorrhea may cease in as little as 3 weeks, so women who do not desire to become pregnant should use a second method of contraception soon after delivery. Safe options for contraception while breastfeeding are listed in Table 1.
Barriers and spermicides
Male condoms Besides preventing the passage of sperm into the female reproductive tract, latex or other 
synthetic male condoms also prevent the transmission of infectious particles, including HIV. Condoms made from natural membranes (such as lamb cecum) block sperm but may be permeable to smaller infectious particles and do not prevent STDs.
Female barriers Advances in contraceptive technology have provided women with three options for barrier protection: female condoms, diaphragms, and cervical caps. Women can insert these barriers into the vagina up to 8 hours before intercourse, which allows for more spontaneity than do male condoms. Female condoms, which are made of polyurethane and fit loosely inside the vagina with a firm external ring, do not provide adequate protection from STDs; nor do diaphragms and cervical caps, which fit tightly over the cervix and prevent sperm migration into the cervical canal. Diaphragms and caps must be fitted by a health care professional.
Spermicide To further prevent sperm from entering the cervical os, any method may be combined with the use of spermicide, which decreases sperm motility and nutrition by inhibiting fructolytic activity. The OTC spermicide most commonly available in this country is nonoxynol-9, formulated as vaginal cream, film, foam, gel, suppositories, and tablets. Spermicidally-coated condoms are also available, but they do not deliver enough spermicide to provide protection beyond condom use alone. Note that spermicides do not protect against STDs and may actually increase the risk of HIV transmission.3 In 2001, the World Health Organization (WHO) declared that nonoxynol-9 spermicide should not be used by women at risk of HIV infection.4 All sexually active persons with risk factors for acquiring STDs must be strongly encouraged to use synthetic barriers with every sexual contact, regardless of need for contraception.
Pharmacologic contraception
Pharmacologic contraception exploits the physiologic actions of estrogen and progestin to block ovulation, alter cervical mucus, and stimulate atrophic change in the endometrium. The mechanism of progestin alone provides contraceptive benefit, although estrogen alone should not be used because it causes endometrial hyperplasia and increases the risk of endometrial cancer.
Combined oral contraceptive (COC) pills These regimens are currently the mainstay of contraceptive therapy, with most women experiencing only mild side effects. Despite their popularity, clinicians should be aware of the potential complications associated with COC use (see Table 2). Clinicians discovered many of the complications two decades ago when hormone concentrations were greater than 50 mcg per pill; WHO now recommends using the lowest effective dosage of hormones.5 Combined pills with less than 50 mcg of estrogen are safe and effective in women who have none of the contraindications to exogenous estrogen listed in Table 3.
Hormonal contraceptives increase the risk of stroke, acute MI, and venous thromboembolic disease. However, the risk attributable to COC use is low because the overall incidence of cardiovascular disease in women of reproductive age is low.6,7 For women with relative contraindications or those who have significant side effects, the clinician and patient must determine together if the risks outweigh the benefits of remaining on a COC regimen. Alternatives may include a different form of contraception or a progestin-only oral contraceptive.
Commercially packaged COC pills provide 21 days of hormone followed by 7 days of placebo pills to allow for withdrawal bleeding. Recently, extended-cycle COCs have been introduced that allow for 1 week of withdrawal bleeding every 3 months with efficacy and safety equal to standard 28-day COCs.8 Any monophasic pill (equal quantity of hormone in each tablet) can theoretically be used in the same way by skipping the seven placebo tablets and starting a new package after taking the 21 active pills. Multiphasic pills are also available; these contain varying amounts of estrogen and progestin in the active pills and attempt to mimic natural hormone fluctuations and to provide the lowest effective dosage of hormone. Because of the varying amount of hormone in multiphasic pills, they must be used in only in the prescribed 4-week cycles.
Combined contraceptive patch Various delivery methods for hormonal contraception have been developed in 
an attempt to improve the poor adherence rates seen with daily pill ingestion. In one, a 4.5-cm square patch containing hormones is applied to the skin, allowing estrogen and progestin diffusion at a constant rate. Patients apply a new patch to the abdomen, buttocks, upper arm, or torso (but not breasts) every week and remove it for the fourth week to allow withdrawal bleeding. The patch may be less effective in women weighing more than 90 kg (198 lbs).9 When compared to COCs, the patch causes slightly increased nausea, breast pain, and irritation at the application site.10 Patch contraception has efficacy similar to COCs, and its unique delivery system improves compliance.10,11
Combined contraceptive vaginal ring This system involves a 2-inch flexible ring that delivers low-dose estrogen and progestin directly into the vagina. The patient inserts one ring into the vagina and leaves it there for 3 weeks; then she removes it for 1 week to permit menstrual bleeding. Vaginal rings remain effective with minor deviations from the recommended protocol, and they have contraceptive benefit similar to COCs with the added advantages of improved hormone delivery and convenience.12,13 Ninety-five percent of women reported that the ring was easy to insert and remove. In addition, 80% of women and 70% of partners did not sense the ring during intercourse.14 Ring and patch delivery systems maintain a constant serum hormone level, which decreases the side effects associated with pulsatile delivery from pill ingestion.