Methods of contraception

By Dr. Elise Dubuc

Choosing a method of contraception that is right for you can be a daunting task as it involves evaluating each method’s risks, side effects, and effectiveness in addition to your overall health, desires, and preferences.

A gynecological examination is not mandatory to have a prescription for contraception; however, your healthcare professional must complete a questionnaire to assess whether you have any contraindications to any of these methods.

Throughout this article, I will differentiate between a “perfect” versus a “typical” use scenario when describing a method’s effectiveness in preventing pregnancy or STI. Perfect use assumes that contraception was used correctly in all sexual situations, while typical use includes oversights generally seen daily.

Contraception is needed if you are in a relationship where one person has ovaries and a uterus, and the other has a penis and testicles, regardless of gender identity.

Natural methods (including symptothermal and calendar)

These methods assume conception can occur when sexual intercourse takes place up to five days before and one day after ovulation. Natural methods of contraception make it possible to avoid having sex during the fertile period; however, it can be used with abstinence or with a barrier method during that same period.

With the calendar method, a woman should know her menstrual cycle for about 6 to 12 months before starting this practice and have relatively regular cycles of 26 to 32 days. To determine the start of the fertile period, subtract 20 days from the shortest cycle length. To determine the end of the fertile period, subtract ten days from the length of the longest cycle. For example, if my shortest cycle was 26 days and my longest cycle was 32, my fertile window would be from day 6 to day 22. During that time, I would have to abstain from sex or use a barrier method.

The symptothermal method identifies symptoms and signs of ovulation, as we will see below.

Cervical mucus: As ovulation approaches, mucus becomes more abundant, clear, and elastic in consistency. Fertility decreases three days after producing more abundant, elastic, clear mucus. After ovulation, the mucus becomes thicker and more opaque and decreases enormously in quantity.

Basal Temperature: Wake-up temperature is measured daily after at least 6 hours of sleep and plotted on a graph. After ovulation, the temperature increases by at least 0.5 degrees Celsius. To avoid pregnancy, a woman should avoid unprotected sex from the beginning of the cycle until after three consecutive days of temperature rise. Women who have a high temperature for reasons other than ovulation, such as a fever, insomnia, or work night shifts, should not use this method.

With perfect use, one-year pregnancy rates are 0.4% for the symptothermal method and 4% for the calendar method. Typical use, however, is a 24% pregnancy rate after one year.

Ovulation Predictor Tests

These tests help those trying to conceive and can help in knowing when ovulation has passed (when the LH reading returns negative) and fertility is now low until menstruation.

Withdrawal (coitus interruptus)

Although not an effective method of contraception (one-year pregnancy rate is 22% in a typical use scenario), it is widely used. In a 2006 study, 11.6% of Canadian women admitted to using the withdrawal method. The failure rate is likely due to sperm present in the pre-ejaculatory fluid and lack of partner control. There is also a high risk of sexually transmitted infections since it involves unprotected sex.

Barrier methods

The male condom: Condoms can prevent pregnancy when used from beginning to end of each sexual encounter. With perfect use, there is a 2% chance of pregnancy, increasing to 18% with typical use. Male condoms may protect against many sexually transmitted infections, but not all. Diseases like the human papillomavirus (HPV) or herpes can still be transmitted via skin-to-skin contact in the genital area, even with a condom.

Latex condoms are the most effective condoms in preventing both pregnancy and STIs. Be careful not to use oil-based lubricants as this can alter the latex and make it less effective. Those allergic to latex can use polyurethane, polyisoprene or silicone condoms, which are slightly more at risk of breaking or slipping. Lambskin condoms are another choice to prevent pregnancy; however, avoid them if trying to prevent STIs.

The female condom: The female condom is a polymer shell which contains two flexible rings. The outer ring is affixed to the outside of the vagina and protects the perineum. The inner ring on the envelope’s closed side inserts inside the vagina. A silicone-based lubricant coats the inner side of the casing. The female condom can be placed in the vagina 8 hours before intercourse and is available at your local pharmacy without a prescription. It is the only contraceptive method that protects against most STIs, specifically for women. The failure rate with perfect use is 5% but goes up to 21% in typical use.

Diaphragm or cervical cap

The diaphragm and cervical caps act as barriers inside the vagina to prevent sperm from entering the cervix. Women must use them with a Contragel type gel which forms an additional cellulose barrier. You can apply it 2 hours before sex, and you must reapply the gel before each new sexual intercourse. The diaphragm and the cap should remain in place for at least 6 hours after intercourse, but no longer than 24 hours (for the diaphragm) and 48 hours (for the cap). These two methods do not protect against STIs. Diaphragms and caps come in various sizes depending on anatomy and are prescribed by a doctor. However, there is a one-size-fits-all diaphragm available without a prescription.

The effectiveness of these methods varies depending on the diaphragms and caps used. With perfect use, 6% of women can get pregnant versus 12-18% with typical use.

The contraceptive sponge and spermicides

The contraceptive sponge is made from polyurethane foam. The only one available in Canada is the Today sponge which contains the spermicide nonoxynol-9 and is available without a prescription in one size only. Its failure rate is 12% to 24%. In addition, spermicides are also among the least effective methods.

Hormonal methods of contraception

These methods change the hormone levels during the menstrual cycle by using synthetic hormones to mimic the action of estrogen and progesterone produced naturally in a woman’s body.

Before starting any hormonal contraception, you should consult a health care professional to verify that you have no contraindications to these hormones. For example, women who have migraines with auras or have already had venous thromboembolism (i.e. a clot in the legs, lungs or brain) cannot take birth control with estrogen.

Combined hormonal methods

These methods contain both estrogen and progestogen. Women can take them cyclically, i.e., a few days to a week without hormones to allow regular menstruation, or continuously without a break. They work by preventing ovulation, thickening cervical mucus, making it difficult for sperm to pass through, and thinning the endometrium.

These methods can be taken as pills, a patch on the skin, or a vaginal ring. They all have the same effectiveness with a failure rate with perfect use of 3% and 9% with typical use. They can also be used to regulate the menstrual cycle, treat pain during menstruation, painful ovulation, repetitive functional cysts and polycystic ovary syndrome.

The birth control pill should be taken every day, ideally at the same time of the day.

The patch is applied weekly on clean, dry skin and different parts of the body (except the breast). You can put it on for three weeks in a row and take a one-week break if you wish to cycle.

The vaginal ring is inserted in the vagina for three weeks and can be removed from a few days to a week if you wish to have regular menstruation. I often recommend that my patients who use the ring put it on the 1st of the month and take it off on the 25th, making it easier to remember.

When starting any of these methods, the most common side effects are irregular bleeding, headache, and nausea, which go away after a few weeks to months of use. Serious side effects are rare in healthy women who have no contraindications. The beneficial effects are a reduction in acne and facial hair, a reduction in the risk of endometrial, ovarian and colon cancer, and may reduce certain symptoms of perimenopause. Women over 35 and who smoke cannot use methods containing estrogen.

Progestin-only methods, such as the progestin-only pill

These methods can be used by women who have contraindications to estrogen, who are 35 years old and who smoke or women who are breastfeeding.

Some women may experience hormonal side effects such as mood swings, increased acne and body hair, headaches and breast pain.

The injection (Depo-Provera)

The progestin injection is given by a healthcare professional every 12 weeks (3 months). It can reduce the amount of menstruation and sometimes even stop them, which can be an advantage if they are heavy or painful. The failure rate is 2% in perfect use and 6% in typical use. In addition to those mentioned with progestogen, side effects can include irregular periods and sometimes even daily spotting, especially at the start of use, and a change in appetite with an average weight gain of 2 kg in some users. The injection may also decrease bone mineral density, but this is reversible upon discontinuation. It would help if you still got enough calcium, vitamin D, and exercise to promote bone health.


The implant is 4cm long and 2mm wide and is inserted by a medical professional in the arm just under the skin under local anesthesia. It’s highly effective contraception with a failure rate of 0.05% for five years. Its primary disadvantage is irregular bleeding and discomfort during installation and removal.

The intrauterine device containing levonorgestrel

For this method, the device is inserted by a healthcare professional during a gynecological examination and does not require anesthesia. The device can cause uterine cramping, which can be alleviated by taking a pain reliever or anti-inflammatory before the procedure.

It is very effective contraception with a failure rate of 0.2%—side effects with progestogen contraceptives can include irregular bleeding after insertion. Many women will have fewer or almost no periods after a few months. Complications with insertion such as infection, perforation of the uterus or expulsion of the device are rare. These IUDs are effective for 5 to 7 years, depending on the amount of levonorgestrel.

The copper intrauterine device

The copper device does not cause the hormonal side effects seen with hormonal contraception methods and is very effective, with a failure rate of 0.8%. Insertion complications are rare, as with the levonorgestrel release device. The main side effects are menstruation which may be heavier and more painful. Like hormonal methods, it does not protect against STIs.

The great advantage of intrauterine devices is that they are invisible, and you may even forget it’s there. They are also reliable and reversible.

Permanent methods of contraception

A vasectomy can be an interesting option in cases where permanent contraception is sought. The procedure is performed under local anesthesia and involves cutting the vas deferens, the channels that bring sperm to the penis. Vasectomies are very effective, involve little risk and do not require a long recovery.

Tubal ligation, either with clips or salpingectomy (i.e. when the tubes are removed), is also an irreversible option. General anesthesia is required, and rare operative risks include bleeding, trauma to adjacent organs (such as bowel, bladder, and blood vessels) and wound infection. Ligation is less recommended nowadays as less risky alternatives exist, such as vasectomy. Often, women who have had ligation will eventually have to opt for hormone therapy for heavy or painful irregular periods.

Definitive methods sometimes cause regret. Life is long, and sometimes a change of partner leads to the desire to start a new family even if an individual was convinced they never want to have children.

Emergency contraception methods

Emergency contraception methods can be used if you have unprotected sex, forget to take your usual contraception, the condom broke or slipped off, or have non-consensual sex.

The morning after pills: Two types of morning-after pills exist. The first is levonorgestrel based, a progestogen. Two doses are taken 12 hours apart, and effectiveness is most significant when taken within 24 hours of unprotected intercourse. However, it can be taken much later (up to 5 days) with less efficiency. This morning-after pill is available in pharmacies without a prescription.

The other morning-after pill is ulipristal acetate based and is available only by prescription. It is more effective over a more extended period, up to 5 days and is more effective than levonorgestrel for people with a BMI over 25.

Copper Intrauterine Device: The most effective emergency contraceptive method is the insertion of a copper IUD within seven days of unprotected intercourse. It also provides a reliable method of contraception for the future.

Regardless of which contraceptive method(s) you decide on, your health care professional is your primary information resource and can answer any questions when making a decision.