Page 164-197, 334 pages Page 1 of 13
Chapter 7: Contraception
• Contraception: Methods intended to prevent or reduce the likelihood of pregnancy, by interfering with
ovulation or fertilization. Some, but not all, also protect against STIs.
• Abstinence is a form of birth control. There are varying definitions, and it is the only 100% effective
• Prior to 1969 amendment of the Criminal Code of Canada by Prime Minister Pierre Trudeau, anyone
who sold or advertised the sale of contraception or provided abortion services could be jailed up to 2
• Laws against abortion were deemed unconstitutional by the Supreme Court in 1988.
• These laws arose from understanding of reproduction as the only legitimate purpose of sex, with
previous statues under “Offences Tending to Corrupt Morals” to protect social values
• Contraception may be used to limit family size, space pregnancies, avoid pregnancy, or avoid high risk
of having a child with defect. They are particularly useful for preventing teen pregnancies.
• Type of contraceptive used affected by woman’s age and relationship status. Worldwide, it is affected
by medical availability, education about contraception, and gender roles.
• Myths include:
o I won’t get pregnant if I have intercourse during my period
o If he withdraws before ejaculation, I can’t get pregnant.
o I can’t get pregnant the first time I have sex
The Combination Pill
• Combination birth control pills contain a combination of estrogen and progestin (synthetic
progesterone), at doses higher than natural levels for 21 days followed by a placebo or no pill for 7 days.
• Variations of duration include Seasonale, with 84 + 7 pills (period every 3 months). Preferred method is
QuickStart with taking pill first day of prescription, regardless of day of her menstrual cycle.
• The pill works by preventing ovulation, since the high levels of estrogen inhibit FSH production needed
for ovulation. The high progesterone also inhibits LH.
• Progestin additionally thickens cervical mucus to prevent sperm migration, and changes uterine lining
to decrease chance of implantation. When the placebo or no pill is used, the uterine lining disintegrates
and causes withdrawal menstruation; the flow is typically reduced due to progestin inhibition of
• Failure Rate: The pregnancy rate occurring using a particular contraceptive method, as percentage of
women who will be pregnant after 1 year of use of this method. E.g. 5 out of 100 pregnant on this method
= 5% failure rate
• Failure rate for perfect users refers to studies of the best use of the method, with user being well-taught
about method and using it with consistency. Failure rate for typical users refers to practical use, including
imperfect use where a condom is not used every time, or forgetting to take a pill.
• Effectiveness: Percentage of non-failure rate, e.g. 95% effective.
• Combination pills have perfect-user failure rate of 0.3% and typical rate of 8%. Failures are primarily
due to forgetting to take a pill for >2 days and not taking it at the same time every day. If forgotten, she
should take one immediately, and the next one at the regular time. Page 164-197, 334 pages Page 2 of13
• If missed >3 days, she should use a back-up method, such as condoms, or abstain from sex until 7
more days of using the pill.
• Serious side effects include slight ↑risk of certain CV diseases, including blood clotting (thromboembolic
disorders) particularly in over-35 smokers. Symptoms include severe headaches, leg or chest pains, and
shortness of breath. Use of the pill can also ↑ risk of high blood pressure.
• No evidence that pill is associated with infertility or difficulty conceiving after termination of use.
• The pill ↓endometrial and ovarian cancer, but may ↑breast cancers and risk of benign liver tumours.
• Pill ↑amount of vaginal discharge and vaginitis due to changing chemical balance of vagina. This can
also ↑susceptibility to chlamydia and gonorrhea.
• Pill may also cause some nausea and weight gain depending on the brand and individual.
• Psychological effects include ↑irritability and depression related to progesterone content, as well as
changes (both increase and decrease reported) in sexual desire and arousal.
Advantages & Disadvantages
• Advantages: Close to 100% effective with perfect use, does not interfere with intercourse, is not messy,
reduces menstrual flow and cramps, reduces acne, protects against PID and ovarian and endometrial
• Disadvantages: Side effects, cost (about $24/month), burden of contraception on the woman, and
education needed for proper use (may not be adequate information available for use in developing
• One criticism is that for a woman who has intercourse infrequently, it may be contraceptive “overkill”
causing increase in side effects for contraception a few times a month.
• No protection against STIs.
• Termination of pill-use can be followed by a brief delay (2-3 months) in becoming pregnant, but
pregnancy rates are similar for women who never took the pill.
• Anti-tuberculosis drugs and St. John’s Wort decrease effectiveness of pill, and up to 30 others may
interact with the pill – important to check with doctor or pharmacist about possible interactions.
• The pill may also reduce metabolism of some drugs, making them more potent and requiring a
decrease in dosage; this includes anti-anxiety drugs, anti-inflammatory corticosteroids, and theophylline
Other Kinds of Pills
• Combination pills vary between brands in dosages of estrogen and progestin, typically with estrogen in
range of 30-35mg as higher doses have higher risk of bloodclotting. On the other hand, high progestin
may cause vaginitis and depression. Depending on side effects to be avoided, a woman can choose
particular brands and dosages.
• Triphasic Pills (Ortho 7/7/7) contain a steady level of estrogen and 3 phases of progesterone, intended
to more closely mimic a woman’s natural hormone cycle and reduce total hormone exposure.
• Stacking is done with monophasic pills, typically up to three months, to avoid menstruation; however,
during this time the endometrium continues to thicken, which may lead to spotting. Triphasic pills cannot
• Progestin-Only Pills (Micronor) are also called mini-pills, containing only a low dose of progestin and
no estrogen designed to avoid estrogen-related side effects. The dosing starts on the first day of her
period and continues every day at the same time daily. Page 164-197, 334 pages Page 3 of13
• Progestin-only pills work by thickening cervical mucus, inhibiting implantation, and inhibiting ovulation
(but less effective – about 40% of women still ovulate consistently). They have a failure rate higher than
• Major side effect is irregular menstrual cycles, but useful for women over 35 who smoke or women who
have history of high BP or clotting problems. They are also useful for women who are breastfeeding
(estrogen reduces breast milk production), although neither kind should be used in first 6 weeks after
birth since trace amounts can be transmitted to the baby.
• The patch (Ortho-Evra) contains the same combination hormones, but administered transdermally in a
thin, beige, Band-Aid sized adhesive patch with protective polyester.
• The patch lasts for 7 days, with the woman using a patch for 3 weeks followed by a patch-free week. An
advantage is the convenience without having to take a pill daily; the hormones also enter through the
skin, rather than being digested through the stomach (there is concern the dosage may be higher).
• Expected to have similar benefits and side effects as the pill, with typical failure rate of 1% -- even
somewhat more effective than the pill.
The Vaginal Ring
• The vaginal ring (NuvaRing) is a flexible, transparent ring made of plastic and filled with hormones like
the combination pill, in lower doses. The ring is placed around the cervix and remains for 21 days,
removed for 7.
• It is very effective at stopping ovulation, may have lower failure rate than the pill because it removes the
problem of missed pills due to problems remembering.
• Emergency Contraception (Plan B) is used for emergencies involving unprotected intercourse that
may result in an unwanted pregnancy, such as a condom breaking. It contains high doses of
levonorgestrel (a progestin), and is best used 72 hours and up to 120 hours after unprotected intercourse
• Side-effects include nausea, irregular bleeding, fatigue, headache, dizziness, and breast tenderness.
• It may work in various ways depending on place in the cycle: stop ovulation, inhibit sperm function,
prevent fertilization, or inhibit endometrial development – but it does not cause abortions or harm existing
• Effectiveness between 75-89% for most fertile period, with actual failure rate 0.5-2%.
• Plan B is available over-the-counter, does not require a physician prescription. This has increased its
use, but not due to promotion of irresponsible contraception; most were used one time due to birth
• Research shows availability of Plan B does not increase unprotected intercourse of number of sexual
• Insertion of a copper IUD up to 7 days after unprotected intercourse is also an effective form of EC,
which can be left in place to provide on-going birth control.
• Thin rods of tubes containing progestin are inserted under the skin of the arm, effective for 3 years.
• Norplant was removed from market due to health concerns; Implanon is available in the US but not
Depo-Provera Injections Page 164-197, 334 pages Page 4 of13
• Depo-Provera (DMPA) is a progestin administered by injection every 3 months, working by inhibiting
ovulation, thickening mucus, and inhibiting growth of endometrium. It has typical failure of 3%, more
effective than pill. It has the highest dosage due to being one single-time shot and distance from cervix.
• Advantages: Does not interfere with intercourse, far less reliance on memory, available for women who
cannot use the combination pill
• Disadvantages: Amenorrhea or spotting (but may be an advantage – relieve anemia, treat
endometriosis), irreversible bone loss after 2 years on drug
• Reversible by not getting another injection; may remain infertile for 6-12 months after but will then
become pregnant at normal rates.
THE IUD & IUS
• Intrauterine Device (IUD) is a small plastic device sometimes combining metal or a hormone, inserted
into the uterus for contraception by a doctor or nurse practitioner; a couple of plastic strings hang down
through the cervix for the woman to check it is in place. It remains until removal is desired.
• The Intrauterine System (IUS) is also T-shaped and contains progestin (Mirena), a hormonal form of
IUD. It contains the lowest dose of hormonal methods due to proximity to the fallopian tubes.
• The IUD prevents fertilization by changing the environment of the uterus and fallopian tubes, so sperm
are immobilized. The egg may also move more swiftly through the tube, reducing chances of fertilization.
• The use of copper alters the enzymes needed for implantation, may be used as emergency
• The IUS release of progesterone reduces the endometrium, thickens mucus, and disrupts ovulation.
• The IUD is extremely effective, with 0.7% failure rate in first year of use and lower after that. The
copper IUD is effective for 12 years, and Mirena for 5 years.
• Most failures occur in first 3 months due to expulsion or unknown reasons; expulsion may occur in
women who have never been pregnant, younger women, and women during menstruation.
Advantages & Disadvantages
• Advantages: The IUD/IUS is a fairly cheap means of contraception long-term, with an initial cost of $80-
$350 for the device and physician visit covered by health insurance. Very low typical failure rate of 0.8%,
better than combination pill. Also simple to use, does not interfere with intercourse, tampon use, or
menstruation, and can be used while breastfeeding.
• Side effects of copper include increased menstrual cramps and flow, and irregular bleeding in 10-20%
of women, typically immediately after insertion.
• Mirena reduces menstrual flow, may cause weight gain, depression, or decreased sexual interest.
• Removal of the device by a physician can allow a woman to get pregnant immediately.
CERVICAL CAPS & THE SPONGE
• The diaphragm was common up to the 1960s, but today
most prefer other methods
• FemCap and Lea’s Shield are vaginal barrier devices.
FemCap is a silicone cap with a dome that covers the cervix
and a brim that conforms to the vaginal walls; it comes in 3
sizes depending on the woman’s obstetric history of pregnancy
and vaginal delivery. Lea’s Shield is a rubber cap which also
fits over the cervix, with a one-way valve to provide suction. Page 164-197, 334 pages Page 5 of13
• Cervical caps can be inserted several hours before intercourse and left in place for up to 48 hours
(leave in for at least 6hrs until all sperm die), and can be reused for about two years. They are typically
used with spermicides.
• Primary action is mechanical by blocking sperm from the entrance of the uterus, and use with a
spermicide can kill any sperm that manage to get past the barrier.
• Typical failure rate is 20%, mostly due to improper use – not using every time, poor fit, not leaving it in
long enough, or not using with a contraceptive cream.
• Even perfect use failure rate is 9% -- should be combined with a condom around ovulation.
Advantages & Disadvantages
• Advantages: Inexpensive (about $40 for 2 year use, plus spermicide cost), few side effects compared
to hormonal or IUD methods, reduction of rates or cervical cancer, some protection against chlamydia
but not most STIs
• Disadvantages: Involves vaginal insertion, prior preparation with insertion and applying a spermicide,
high failure rate
• The contraceptive sponge is another vaginal barrier method, made of polyurethane and shaped like a
round pillow with a concave dimple on one side.
• It contains spermicide, inserted over the cervix, and is effective for 24hrs (must leave in for at least
6hrs). However, there is risk of toxic shock syndrome if left in for over 24hrs.
• Available over-the-counter without prescription. Perfect failure rate is 10-20%, typical failure rate 16-
The Male Condom
• The male/phallic condom is a thin sheath that unrolls to fit over the penis, typically made of latex
• The rubber condom was first developed around 1843, although sheaths have been used to cover the
penis for centuries for both contraception and protection against diseases.
• Proper use includes coverage before penis ever enters the vagina, not just before ejaculation since
some pre-ejaculate may also contain sperm, and to protect against STIs. The maintenance of an air-free
space at the tip of the penis and holding the rim of the condom during withdrawal help prevent leakage.
• The condom catches semen and thus prevents its entrance into the vagina. Condoms may also be
coated with spermicide, but they may become allergens and are likely not enough to kill sperm compared
to use of a foam.
• Polyurethane varieties are available, but they are less flexible and need more lubrication (slightly lower
efficacy due to improper use) – although thinner, transmit more heat.
• Perfect failure rate of 2%, and typical failure rate of 18% from improper or inconsistent use – chances of
defects in condoms themselves are small. Can be combined with contraceptive foam or vaginal barrier
Advantages & Disadvantages
• Advantages: Only contraceptive method available for men other than sterilization, cheap and readily
available, protect against STI transmission by being a barrier against genital secretions (chlamydia,
gonorrhea, trichomoniasis, hepatitis B, HIV) and some skin-to-skin contact
• Disadvantages: Must be put on just before intercourse, reduction of sensation and pleasure for the
penis (though may help delay ejaculation) Page 164-197, 334 pages Page 6 of 13
The Female Condom
• The female/reality condom is made of polyurethane, with one ring at each end; one ring is inserted
into the vagina and the other spread over the vaginal entrance. It can also be used in the anus, with inner
• It provides a barrier against sperm, keeping it from entering the vagina and uterus. A new female
condom must be used with each act of intercourse.
• The typical failure rate is 21%, and perfect failure rate of 5% -- this is unacceptably high.
Advantages & Disadvantages
• Advantages: Woman can active prevent STI transmission, inserted up to 8 hours before intercourse
• Disadvantages: Spontaneity problem, awkward to insert and makes rustling noises while in use, least
effective method, higher cost than male condoms, polyurethane is more susceptible to tearing and
• Few side effects, although some experience vaginal irritation.
• Spermicides are substances (nonoxynol-9) that kill sperm, and come in foams, creams, and jellies
which may be applied with an applicator from a tube or as a film (VCF). They must be left for 6-8hrs after
• Spermicides use a chemical to kill sperm, while the inert base mechanically blocks the cervical
• Failure rates are as high as 25%, with foams being the more effective medium. Spermicides are only
highly effective when used with a condom or vaginal barrier method, such as a diaphragm.
• They are also abrasive, and can cause microscopic tears in the mucosal membrane – partner being
penetrated may be at increased risk of STIs.
• Advantages: Readily available, stop-gap method before a woman can see a physician and get a more
effective form of contraceptive
• Disadvantages: Some have an allergic reaction to spermicides, no protection against STIs, taste
• Douching is flushing the inside of the vagina with a liquid. It is not effective as a contraceptive method
since it only takes seconds for some sperm to reach the cervical mucus, with douching not able to occur
quickly enough after ejaculation to prevent some from entering the uterus. The douche itself may push
sperm up into the uterus.
• Withdrawal is the most ancient form of birth control, with the man withdrawing his penis from his
partner’s vagina before he orgasms, ejaculating externally.
• Failure rate of 27% since pre-ejaculate fluid may carry enough sperm for conception to occur; semen
that occurs outside the vagina but near or on the vulva can still reach the uterus. The man may not
withdraw in time.
• Worrying about ejaculating before withdrawal may contribute to sexual dysfunctions.
• Advantages: Last-minute method which can be used when nothing else is available, free
• Disadvantages: Ineffectiveness, requires motivation on the part of the man with self-conscious control
and worry for the woman about withdrawing in time Page 164-197, 334 pages Page 7 of 13
FERTILITY AWARENESS (RHYTHM) METHODS
• Fertility Awareness (Rhythm) Methods are the only form of “natural” birth control, involving
abstaining from intercourse during the woman’s ovulation period; various forms involve various ways to
determine this fertile period.
• Calendar Method: This determines ovulation by keeping a calendar record of the woman’s menstrual
cycles, assuming ovulation occurs 14 days (or 13-15 range) after onset of menstruation.
• The couple must thus abstain from intercourse from day 10-17 (previously deposited sperm can live for
a few days, and eggs may be long-lasting).
• A woman who is not perfectly regular must record her cycles for 6 months to 1 year to determine the
variability of her cycles. The preovulatory safe period is calculated by subtracting 18 from days in the
shortest cycle, an