E.J. Mayeaux, Jr., M.D.
Assistant Professor Departments of Family Medicine and Obstetrics and Gynecology
Louisiana State University Medical Center Shreveport, Louisiana
A patients request for contraceptive counseling may occur in conjunction with other problems or be the main reason for a scheduled appointment. It is not only important for the physician to give correct and complete information but also to match the contraception method to the particular needs of each patient. Many factors are important to consider.
Motivation is a very important factor because all methods except IUDs, Norplant System and sterilization require patient involvement. Patients need proper counseling to select an appropriate birth control method and education concerning their chosen method. Typical and actual failure rates are shown in Figure 1.
Periodic Abstinence is a contraceptive method that requires tremendous motivation in the patient and their partner. This method encompasses several adjunctive procedures including cervical mucus testing and symptothermal recording. These adjuncts are used to help determine fertile periods. The typical failure rate is 20% per year. This means 20% of women using this method will experience accidental pregnancy in one year. The main advantage as in barrier methods is no exogenous hormone exposure. Some religious groups only allow the use of this method for contraception.
The Diaphragm, Cervical Cap, and Sponge are all barrier methods of contraception. These can be useful if the partners are very motivated. They work often in conjunction with spermicidal foams or jellies by blocking the passage of sperm through the cervical canal. They are useful when the woman does not wish to or can not use hormonal contraceptives. This is especially useful with chronic drug therapy and breast feeding. The cervical cap and diaphragm require fitting by a doctor and the cervical cap should not be used during menses. They must be inserted or applied before intercourse which occasionally causes problems with spontaneity.
Of the methods listed so far, only IUDs do not require high motivation and attention. How they work is not really understood but it is theorized that they interfere with sperm transport, fertilization, and implantation. However they work, their efficacy rate is about 98%. IUDs may contain copper or a progestin. Several factors must be taken into account before deciding on IUDs. First, IUD users may be at greater risk for pelvic inflammatory disease, particularly in nonmonogamous relationships. However, The most recient studies on modern IUDs do not bear out this relationship. Second, women who become pregnant with an IUD have an increased risk of ectopic pregnancy. It is contraindicated in women with a history of PID or ectopic pregnancy. It is appropriate in a parous woman who is in a monogamous relationship and who wishes reversible contraception. Upon removal of an IUD, 75% of women trying to get pregnant will do so within 1 year.
Sterilization is accomplished by surgical disruption of the vas deferens in the male or the fallopian tubes in the female. It has an almost 100% efficacy rate. You should inform the patient that it is permanent and reversal rates are quite poor. It should only be used with people who feel certain they do not desire additional children. Vasectomy is generally an outpatient procedure. Tubal ligation can be done anytime including post delivery using a laproscope. Complication rates for both are low.
Oral contraceptives (OC) are some of the most effective, easily reversible, and common contraception methods used today. Currently over 13.5 million women use this form of birth control. It is easy and doesn't need to be used just before sex, thus enhancing spontaneity. There has been much concern recently about risks associated with oral contraceptives. It must be remembered that the amount of hormone is much lower in modern oral contraceptives than when they were first introduced and studied. Figure 2 shows some relative risks for various activities women may voluntarily participate in.
Studies in the late 1960s and early 1970s showed that 50 mg estrogen pills did increase the risk from thromboembolic disease. Modern studies have shown that the 30 mg estrogen pills in use today have little to no effect on thromboembolic problems. In fact, the low dose estrogen may have a positive effect on the cardiovascular system and lipids. OCs also decrease the incidence of endometrial cancer by 50% and ovarian cancer by 40%. There has been some concern about OCs and the risk of breast cancer. The largest and best designed studies and meta-analysis on this subject show there is probably no overall increase in risk. Debate is ongoing but the best evidence to date looks promising.
The Norplant System is a new implantable birth control method. Its 6 Silastic capsules release progestins continuously over a 5 year period. It has a 0.2% typical failure rate and needs no attention once it is inserted. There is no age of discontinuation and it has no estrogen dependant side effects. Its main disadvantages are high front end cost (although it is cheaper than OCs for 5 years) and it is less effective in overweight women (>150 pounds). It commonly causes irregular menses for up to a year. It of course requires a minor surgical procedure.
Depot medroxprogsterone acetate or DMPA (Depo-provera, Upjohn, Kalamazoo, MI) can be given every 3 months to provide reversible contraception. Has been used by over 90 million women worldwide. It provides at least 14 weeks of contraception per injection. Mechanisms of action include inhibition of ovulation, thickening of cervical mucus, and endometrial atrophy, and decreased motility of the fallopian tubes. Fecundity usually returns in 4 to 9 months.
Patients best suited to this method include women who: can not consistently use user dependant birth control, can't tolerate or have contraindications to estrogen such as women over age 35, and contemplating but have not decided on sterilization or longer term contraception such as Norplant. It is cntraindicated in known hypersensitivity to the drug, undiagnosed abnormal uterine bleeding, pregnancy, active liver disease, liver tumors, and suspected or active breast cancer, active thrombophlebitis or thromboembolic disorders.
The dose is 150mg IM every 3 months. The injection should be given within 5 days of the onset of menses. If given beyond this time, an alternate birth control method should be used for 1 month. If reinjection is delayed more than 2 weeks, a pregnancy test should be done. It may also be given 6 weeks postpartum. It is excreted in breast milk but causes no other changes in the milk and infants exposed and studied demonstrated no adverse effects. The 150 mg/ml concentration should be used for contraception, not the 400 mg/ml concentration. The injection is given deeply in the gluteal or deltoid muscles using a 21 or 23 gauge needle.
Complications include irregular bleeding and spotting, amenorrhea, weight gain, and less commonly headaches, bloating, dizziness, mood changes, and palpitations. It may increases LDL and total cholesterol. NO association was found between Depo-Provera use and breast cancer in human studies. NO change in clotting parameters at 3 months and no increase in thrombosis at 15 months.
There are more types of effective birth control available than ever before. The key to providing the best service to our patients entails providing complete patient education for each potential method. Then the patient and physician together can decide which method is best for each individual.