Birth control methods can be divided into non-permanent and permanent options. Permanent options include tubal occlusion and hysterectomy in the female and vasectomy in the male.

Various factors may affect the reliability of a particular non-permanent birth control method. These include 1) frequency of intercourse, 2) whether factors affecting fertility are present (such as endometriosis), 3) patient weight, 4) other medications used, and 5) proper and consistent use of the method chosen. Overall, 48% of the pregnancies that occur in the United States are unintended. Also, women of any reproductive age may become pregnant unexpectedly. The most effective methods are those that do not require much effort by the user.

Reversible or non-permanent contraception or birth control can be divided into several categories.

• rhythm
• withdrawal
• barrier methods

The fewest number of failures of contraception with resulting pregnancy are found with the following:

• intrauterine device
• hormonal contraception

The rhythm method involves avoiding intercourse around the time of ovulation. Ovulation normally occurs about 14 days before the onset of the next menses. Using this fact, the time of ovulation can be calculated with reasonable accuracy. Also, many women notice a thick, clear, sticky mucous 1-2 days prior to ovulation. If intercourse occurs more than a few hours after ovulation, the chance of pregnancy is very small. In most cases, avoiding intercourse a few days before ovulation markedly reduces the chance of pregnancy. But, pregnancy has been documented with intercourse occurring 9 or 10 days prior to ovulation.

Withdrawal of the penis before ejaculation reduces the chance of pregnancy but is certainly not foolproof. Some sperm are ejaculated prior to the sensation of ejaculation, which can result in undesired pregnancy.

Barrier methods include spermicidal film, gel, and foam. Male and female condoms, the cervical cap, and the diaphragm are also barrier methods. The major drawback of these methods is that they have to be used at the time of intercourse. Most studies show an overall pregnancy rate of approximately 25% over a 6-month period of time with barrier methods.

The intrauterine device received a bad name due to complications associated with an IUD called the Dalkon Shield. There were a number of serious infections associated with the Dalkon Shield causing it to be taken off of the market in the mid 70’s. Two IUD’s are currently available including the Paraguard T® and Mirena®. The Paraguard T is a small T-shaped plastic device that is wrapped with copper; the device may be left in place for 10 years for contraception. The Mirena IUD contains a progestin, levonorgestrel, and is approved for use for 5 years. The IUD is usually inserted in your doctor’s office during your menses. Some physicians will give a local nerve block in the cervix to reduce discomfort with insertion. Most patients describe moderate menstrual-like cramping with the insertion. The major risk of the IUD is an infection involving the uterus, tubes, and ovaries, which can potentially block the tubes and cause sterility. The IUD may a good choice for women who have finished their childbearing and who should not take the oral contraceptive pill for various reasons.

Hormonal contraception includes:

• oral contraceptive pills
• quarterly injections
• hormonal patch
• vaginal ring

An oral contraceptive pill (OCPs) is the most popular choice for non-permanent birth control for women in the United States. When used properly, OCPs are very effective in preventing pregnancy. A missed pill is the most common reason for unplanned pregnancy while using OCPs. The OCP is most often started on the first Sunday after the onset of the menses. If the menses begins on a Saturday, the pill is started the next day. If the menses begins on a Sunday, the pill is started the following Sunday. In most cases the pill is effective the first cycle. To be on the safe side, a barrier method of birth control should be used the first cycle. Most women take the pill at the same time every day, perhaps when brushing your teeth or washing your face first thing in the morning or just before going to bed. If one pill is missed, take it as soon as it is realized the pill was missed. Missing one or more pills can cause break-through bleeding and increase the chance of pregnancy.

Most OCPs are combination pills containing both an estrogen and a progestin. Modern combination OCPs contain 35 micrograms or less of estrogen, compared to much higher dosages in previous OCPs. The lower dosages have resulted in fewer side effects. A few OCPs contain progestin only. The progestin-only OCPs may be used while breast-feeding and if there is a history of blood clots (usually in the pelvis, legs, or lungs). These pills have a higher incidence of break-through bleeding and unplanned pregnancy.

In addition to providing contraception, OCPs may reduce heavy bleeding, menstrual cramping, and in certain instances complexion problems. The choice of the particular OCP should be an individual one between the physician and the patient.

There are certain situations when caution should be exercised in considering use of OCPs.

• overweight – Recent studies have shown that women who weigh more than 155 pounds are more likely to become pregnant while using OCPs.
• blood clots (venous thromboembolism or VTE) - Women with a history of VTE should not take the combination OCP unless they are currently taking anticoagulants, and then should be used with caution
• over 35 years of age – OCPs may be used in women over 35 years of age if they are non-smokers and have no other contraindications for their use. The risk of heart attack increases significantly in women over 35 who smoke who take an OCP with 50 micrograms or more of estrogen. Most OCPs today have less than 50 micrograms of estrogen, but the lower dosages have not yet proven to be safe when over 35 and smoking.
• smoking – All women should be encouraged to quit smoking. The safest choice in a smoker of any age may be to choose another method of contraception. This definitely applies to women over 35 years of age.
• chronic high blood pressure (HBP) - Because of the risk of VTE, combination OCPs should not be used by women with HBP. The progestin-only OCP may appropriate for women with HBP
• diabetes – Women with diabetes who are non-smokers and have no evidence of HBP or kidney, eye, and vascular disease may safely take OCPs.
• migraine headaches – OCP’s may be used by women with migraine headaches who have no focal neurologic signs, do not smoke, are under 35, and are otherwise healthy.
• family history of breast cancer or personal history of fibrocystic breast disease – There is no evidence of any increased risk of breast cancer in women using OCPs.
• high cholesterol – Women with uncontrolled LDL cholesterol (160mg/dL) or with other risk factors for coronary artery disease should consider use of other contraceptive methods. Women with controlled LDL cholesterol without other risk factors for heart disease may take OCPs.
• breast feeding – Women may take the progestin-only OCP while breastfeeding.
• other medications – Certain medications may interact with OCPs and may reduce the effectiveness.
• anticonvulsants – Barbituates, phenytoin, carbamazepine, felbamate, topiramate, and vigabatrin reduce the levels of hormones in women taking OCPs. Valporloc acid, gabapentin, lamotrigine, and tiagabine do not have this effect.
• antibiotics – Rifampin and griseofulvin reduce the levels of hormones in women taking OCP’s. Tetracycline, doxycycline, ampicillin, metronidazole, and quinolones have been implicated in anecdotal reports reports of pregnancy while taking OCPs. But these latter antibiotics do not reduce the levels of hormones in women taking OCPs.
• uterine fibroids (leiomyomata) – OCPs may be used in women with uterine fibroids and may reduce cramping and bleeding. If cramping and bleeding persist, other therapies should be considered. The patient should be aware of the possibility that estrogen may make fibroids grow.

The quarterly injection (depo-provera®) has been used for a number of years. The medication, depo-medroxyprogesterone acetate, is given initially during the menstrual cycle, and subsequently every three months. This method should not be used if pregnancy is desired within a year. After the initial one or two injections, many women have no menstrual bleeding at all; some women have irregular bleeding that is usually not heavy. Occasionally premenstrual syndrome is worsened and some patients may experience weight gain when using this method. Recent medical study has raised a concern about increased risk of osteoporosis in women using depo-provera®. You should discuss this with your physician.

The hormonal patch (ortho evra®) contains ethinyl estradiol 20 mcg and norelgestromin 150 mcg. One patch per week is applied for 3 weeks of a 4 week cycle. The patch should not be applied to the breasts.

The vaginal ring (nuvaring®) releases the lowest dose of ethinyl estradiol (15 mcg) in addition to etonogestrel (120 mcg). The ring is self inserted and removed, worn for 3 out of 4 weeks.

No matter which method of contraception is chosen, consistent usage is very important to prevent unplanned pregnancy. The only methods of contraception that prevent/reduce sexually transmitted disease.  The decision to choose the best method should be one that you and your physician make together.