What are Contraceptive Methods?
Contraceptives, or birth control methods, prevent or reduce the chance of pregnancy. They work by interfering with conception: blocking ovulation, blocking fertilization, or making the uterus hostile to implantation.
Before starting any method, work the assessment:
- Run a pregnancy test first to confirm the woman is not already pregnant.
- Get the OB history, any past STDs, the status of past pregnancies, and any method that failed before.
- Assess her needs, preferences, desires, and feelings about family planning.
- Assess sexual practices, frequency, number of partners, and any latex allergy.
Natural Family Planning
Natural methods introduce no chemical or foreign body. They appeal to patients with religious objections to other methods and to those who want the lowest cost.
Abstinence
Abstaining from intercourse is the most effective natural method, with an ideal 0% fail rate, and the most effective way to avoid STIs. Most people find it hard to sustain, so few rely on it.
Calendar Method
Also called the rhythm method. The woman avoids coitus on her fertile days. She is likely to conceive 3 or 4 days before and 3 or 4 days after ovulation. To find her safe days, she records her menstrual cycle for 6 months, subtracts 18 from her shortest cycle (the first fertile day) and 11 from her longest cycle (the last fertile day), and avoids coitus from the first fertile day through the last. Ideal fail rate 5%, typical fail rate 25%.
Basal Body Temperature
BBT is the woman's temperature at rest. It falls 0.5°F before ovulation, then rises a full degree at ovulation from progesterone and holds that level through the rest of the cycle. She takes her temperature early every morning before any activity. A slight dip followed by a rise means she has ovulated, and she abstains for the next 3 days. Ideal fail rate 9%, typical use fail rate 25%.
Cervical Mucus Method
Based on cervical mucus changes at ovulation. At ovulation the mucus is copious, thin, and watery, and shows spinnbarkeit: it stretches at least 1 inch and feels slippery. The fertile window lasts as long as the mucus is copious and watery, plus one day after, so she avoids coitus during that time. Typical fail rate 25%.
Symptothermal Method
A combination of BBT and cervical mucus. She takes her temperature every morning before getting up and notes daily mucus changes. She abstains for 3 days after a temperature rise or on the fourth day after the mucus peak. Ideal failure rate 2%.
Ovulation Detection
An over-the-counter kit that predicts ovulation by detecting the luteinizing hormone surge 12 to 24 hours before ovulation. It tests a urine specimen for LH. The kit is 98% to 99% accurate and is becoming a method of choice.
Lactation Amenorrhea Method
Exclusive breastfeeding suppresses ovulation. It only works with exclusive breastfeeding. Advise the woman to plan another method after 3 months of exclusive breastfeeding.
Coitus Interruptus
One of the oldest methods. The man withdraws before ejaculation to deposit sperm outside the vagina. Pre-ejaculation fluid carries a few sperm that can fertilize, so it is only 75% effective.
Hormonal Contraception
Hormonal methods manipulate the hormones that drive the menstrual cycle so ovulation does not occur.
Oral Contraceptives
The pill contains synthetic estrogen and progesterone. Estrogen suppresses FSH and LH to block ovulation. Progesterone decreases cervical mucus permeability to limit sperm access to the ovum.
- She takes the first pill on the first Sunday after menstrual flow begins, or as soon as it is prescribed.
- The first 7 days give no protection, so the couple uses another method during those 7 days.
- If she skips one day, she takes it as soon as she remembers, then resumes the regular schedule.
- If she misses more than one day, the couple uses alternative contraception to avoid ovulation.
- Side effects: nausea, weight gain, headache, breast tenderness, breakthrough bleeding, vaginal infections, mild hypertension, depression.
- Contraindications: breastfeeding, age 35 and above, cardiovascular disease, hypertension, smoking, diabetes, cirrhosis.
Transdermal Patch
Combines estrogen and progesterone in a patch. For three weeks, she applies one patch a week to the upper outer arm, upper torso, abdomen, or buttocks. No patch in the fourth week, when menstrual flow occurs. The site should be clean, dry, free of other applications, and without redness or irritation. She can wear it bathing or swimming. If it loosens, she replaces it immediately. If it has been loose less than 24 hours, no backup is needed. If she is unsure how long it has been loose, she replaces it, starts a new week cycle, and uses a backup method.
Vaginal Ring
A silicone ring that releases estrogen and progesterone and surrounds the cervix. Inserted vaginally, it stays for 3 weeks and comes out in the fourth week for menstrual flow. She is fertile as soon as it is removed. Same effectiveness as oral contraceptives.
Subdermal Implants
Two rod-like implants placed under the skin during menses or on the 7th day of menstruation to confirm she is not pregnant. They contain etonogestrel, desogestrel, and progestin. Effective for 3 to 5 years. Fail rate 1%.
Hormonal Injections
Medroxyprogesterone and progesterone, given intramuscularly once every 12 weeks. It inhibits ovulation and changes the endometrium and cervical mucus. Do not massage the site, so it absorbs slowly. Almost 100% effective. Because it risks decreased bone mineral density, advise adequate dietary calcium and weight-bearing exercise.
Intrauterine Device
A small, T-shaped device inserted into the uterus through the vagina. It creates a local sterile inflammatory condition that prevents fertilization and implantation. Only a physician fits it, and it goes in after menstrual flow to confirm she is not pregnant. It contains progesterone and is effective for 5 to 7 years. Advise her to check her menstrual flow and the IUD string monthly and to have a yearly pelvic exam.
Chemical Barriers
Spermicides, vaginal gels, creams, and glycerin films kill sperm before they enter the cervix and lower vaginal pH so it is not conducive to sperm. They do not prevent STIs but need no prescription. Used alone, spermicides are among the least effective methods, with a typical use failure rate of about 28 percent (CDC).
Diaphragm
A circular rubber disk that fits the cervix and blocks sperm from entering. Placed before coitus. With spermicide, the failure rate is 6% ideal and 16% typical. A physician fits it. It stays in for 6 hours after coitus and no more than 24 hours total to avoid inflammation or irritation.
Cervical Cap
A soft rubber barrier shaped like a thimble with a thin rim, fitted on the rim of the cervix. Stays in place no more than 48 hours.
Male Condoms
A latex or synthetic rubber sheath placed on the erect penis before penetration to trap sperm at ejaculation. It prevents STIs and is bought over the counter with no fitting. Ideal fail rate about 2 percent; typical use fail rate is about 18 percent from breaks, slippage, or inconsistent use (HHS Office of Population Affairs). Remove and dispose after intercourse.
Female Condoms
Latex sheaths designed for females and prelubricated with spermicide. An inner ring covers the cervix and an outer open ring sits against the vaginal opening. Disposable, no prescription. Fail rate 12% to 22%.
Surgical Methods
Surgical sterilization is among the most effective methods and is permanent. One version is for males, one for females.
Vasectomy
A small incision on each side of the scrotum. The vas deferens is tied, cauterized, cut, or plugged to block sperm. Done under local anesthesia, with mild local pain afterward. Sperm can stay viable in the vas deferens for 6 months, so the patient uses a backup method until two negative sperm counts. Accuracy 99.5%, with few complications.
Tubal Ligation
The fallopian tubes are cut, cauterized, or blocked to stop sperm and ova from meeting. Done after menstruation and before ovulation through a small incision under the umbilicus, with a laparoscope for visualization and local anesthesia. She may resume sexual activity 2 to 3 days after. The menstrual cycle continues. Coitus before ligation must be protected to avoid ectopic pregnancy. Effectiveness 99.5%.
Frequently Asked Questions
What is the difference between ideal and typical use failure rates? Ideal (perfect) use assumes the method is used correctly every single time. Typical use reflects how people actually use it, including missed pills, late patches, and condom slips. Typical rates are always higher, which is why patient teaching matters as much as the method itself.
Which methods are most effective? The implant and intrauterine devices are the most effective reversible methods, with failure rates under 1 percent in typical use, because they remove the chance of user error. Sterilization (vasectomy and tubal ligation) is permanent and over 99 percent effective (HHS Office of Population Affairs).
Which methods protect against sexually transmitted infections? Only abstinence and male or female condoms reduce STI risk. Hormonal methods, IUDs, and sterilization do nothing against infection, so a patient using one of those for pregnancy prevention may still need a condom for protection.
How effective are spermicides used alone? Not very. Used by themselves, spermicides have a typical use failure rate of about 28 percent, so they work best paired with a barrier method like a diaphragm or condom (CDC).
What should the nurse assess before starting any method? Confirm the patient is not already pregnant, take an OB and STI history, review past method failures, and ask about preferences, frequency of intercourse, number of partners, and any latex allergy. The right method is the one the patient will actually use consistently.
How long after a vasectomy is a man considered sterile? Not immediately. Sperm can remain viable in the vas deferens for up to several months, so the couple uses a backup method until two semen analyses confirm no sperm.