How Effective are Different Types of Contraception?

Women have many contraceptive options nowadays, and women can find options to suit their health, lifestyle, and desire to postpone pregnancy for a few months or several years. They include hormonal and non-hormonal methods.

Hormonal methods

These include several forms which are administered orally in a pill or other methods, such as a vaginal ring or a skin patch. They may contain both estrogen and progestogen, or only progestogen. The commonly used methods include:

• The combined oral contraceptive pill

The combined oral contraceptive pill consists of estrogen in the form of ethinyl estradiol, and a progestin such as levonorgestrel or desogestrel. These are taken daily to sustain a persistently low level of these hormones in the blood and so suppress the natural hypothalamopituitary-ovarian cycle which maintains ovulation. They have the disadvantage of having to be taken at the same time every day for adequate contraceptive effect, and so depend upon the woman’s memory. They are theoretically 99.7 percent effective, but the actual efficacy is 92 percent because many women miss pills quite often.

• The vaginal ring

This device releases estrogen and progestogen in a sustained slow manner to suppress the natural ovarian cycle and inhibit ovulation. It is worn for three weeks and removed for the last week to allow bleeding to occur. It is almost 100 percent effective if properly used, but in reality typical results are 90 percent contraceptive efficacy.

• The contraceptive patch

The contraceptive patch is a patch designed to stick firmly to the skin, and is waterproof. It contains estradiol and a progestin, which are absorbed slowly through the skin. It acts in the same way as the oral contraceptive pill. It has an efficacy of over 99 percent if properly used.

• The mini-pill

This is a progestogen-only pill which thickens the cervical mucus and so hinders the free passage of sperm into the uterine cavity. This inhibits fertilization. It has an effective contraceptive rate of almost 100 percent if properly used, but as most women occasionally skip pills, its actual efficacy is closer to 90 percent.

• The contraceptive injection

The contraceptive injection such as depot medroxyprogesterone acetate (DMPA, Depo-Provera) is used every three months for as long as the woman desires to use this method of contraception. It releases a low dose of progesterone over time to suppress normal ovulation, thicken cervical mucus, and prevent endometrial maturation, thus preventing conception. It is 94 percent effective in practice, but has the potential to be almost 100 percent effective, if used perfectly.

• The contraceptive implant

The contraceptive implant releases a progestin such as levonorgestrel or etonogestrel. It is made up of one or two rods containing the drug. It acts in the same way as the contraceptive injections, but for three years at a time. It is close to 100 percent effective as it does not depend upon individual compliance or memory.

• Hormone-containing intrauterine devices

The progestin-releasing intrauterine devices (IUDs) last for 5 years and act like other progestogen-only methods. They may cause irregular bleeding or amenorrhea. Their contraceptive efficacy is 99.8 percent.

Non-hormonal methods

• Barrier methods

These comprise of  the female condom or vaginal diaphragm, or the male condom:

• The female condom

The female condom is a soft plastic tube or pouch with a ring at one end which is used to line the vagina and so prevent the passage of sperm through the cervix. It can be up to 95 percent effective, but since many women fail to use it consistently before intercourse, or use it improperly, the actual efficacy is around 79 percent.

• The male condom

The male condom is a latex or polyurethane sheath used over the male reproductive oragn when erect, to receive the ejaculated semen and prevent its passage into the vagina. The male condom can be 98 percent effective with perfect use, but its actual efficacy is 82 percent.

• The vaginal diaphragm

The vaginal diaphragm is a silicone cap worn over the cervix to block the passage of sperm from the vagina to the uterus. It can be 88–94 percent effective if used properly all the time, but under actual conditions it achieves about 88 percent efficacy.

• Copper intrauterine devices

The copper-containing IUDs release ionic copper into the endometrial cavity and cause it to become unfavorable to the sperms as well as to the fertilized ovum. Their duration of action is from 5 to 10 years, and they are 99.4 percent effective. They can also be used for emergency contraception.

Natural family planning

• The rhythm or Billings method

This is based upon sexual abstinence until regular menstruation starts, indicating the resumption of the ovarian cycles and fertility. At this time, abstinence is limited to the days outside the fertile period, which is determined using methods such as the basal body temperature chart or cervical mucus charting. This method is about 75 percent effective as used, though with proper use it could avoid pregnancy in 95 to 100 percent of women.

• Withdrawal method

The withdrawal method consists of removing the man's reproductive organ from the vagina just before ejaculation, but is not foolproof for several reasons. The male partner may forget to remove his organ, or some sperm may emerge before ejaculation. It is also possible for sperms ejaculated at the entrance to the vagina to swim up and enter the cervix, resulting in fertilization. Thus, the theoretical 96 percent efficacy is lowered to a more realistic 80 percent protection rate in actual life.

Surgical sterilization

• In females: tubal sterilization

This is a permanent method of contraception, and is safe as well as inexpensive if performed in the immediate postpartum period. The fallopian tubes are transected and ligated. It requires proper and extensive counseling beforehand to ensure that the woman or the couple do not have regrets later. Since this procedure is usually performed within a few days of birth, the decision should be made before labor starts.

• In males: vasectomy

This refers to male sterilization by transecting and ligating the vasa deferentia of the testes, which carry sperms out to the urethra for ejaculation. These methods are 99 percent effective.

Emergency contraception

Emergency contraception is a term used for preventing conception after unplanned and unprotected intercourse. It comprises the following types, which may be used by lactating mothers as well:

• Levonorgestrel-containing emergency pill or the ‘morning after’ pill can be bought over the counter. It is 85 percent effective if taken within 72 hours of intercourse, but less effective thereafter.
• The copper-releasing intrauterine device which is very effective if inserted within five days of the episode of intercourse, and has the additional benefit of providing continued protection against conception.
• The ulipristal acetate pill which is available only under prescription.

References

1. https://medlineplus.gov/ency/article/001946.htm
2. https://www.ncbi.nlm.nih.gov/pubmed/8736720
3. https://www.ncbi.nlm.nih.gov/pubmed/25264698
4. http://www.nhs.uk/Conditions/contraception-guide/Pages/when-contraception-after-baby.aspx
5. https://www.betterhealth.vic.gov.au/health/healthyliving/Contraception-after-childbirth

Further Reading

• All Contraception Content
• Advantages and Disadvantages of the Contraceptive Patch
• Advantages and Disadvantages of the Contraceptive Implant
• Advantages and Disadvantages of the Contraceptive Vaginal Ring
• Do Contraceptive Injections Affect Bones?

Written by

Dr. Liji Thomas

Dr. Liji Thomas is an OB-GYN, who graduated from the Government Medical College, University of Calicut, Kerala, in 2001. Liji practiced as a full-time consultant in obstetrics/gynecology in a private hospital for a few years following her graduation. She has counseled hundreds of patients facing issues from pregnancy-related problems and infertility, and has been in charge of over 2,000 deliveries, striving always to achieve a normal delivery rather than operative.