Birth Control, various methods used to prevent pregnancy. Birth control is also known as contraception or family planning.
Pregnancy occurs as a result of a sperm fertilizing an ovum (egg) and implanting in the womb (see Human Reproduction). One ovum is released from a woman’s ovary on day 14 of her menstrual cycle and survives for 48 hours. This process occurs from puberty until menopause. Sperm is produced in the male testes from the onset of puberty. Millions of sperm leave the body by travelling through the vas deferens (the tubes that carry sperm from the testes to the penis), where they join with fluid from the prostate and seminiferous tubules and are ejected from the male’s body through the urethra. This process is called ejaculation. Sperm can live for between three and seven days. For fertilization to occur, the sperm must travel through the vagina, cervix, and uterus to the Fallopian tubes (the tubes that carry the ovum from the ovaries to the uterus). Fertilization usually occurs in the Fallopian tubes, and the fertilized ovum then travels to the uterus where it implants, resulting in pregnancy.
Contraception prevents pregnancy either by preventing sperm from meeting an ovum or by preventing a fertilized ovum from implanting in the uterus. Contraception can be temporary or permanent and can be hormonal or nonhormonal. There are also natural contraceptive techniques. Which type of contraception people use depends on the availability of contraceptive methods, education, risks, benefits, suitability, and effectiveness.
II HISTORY OF CONTRACEPTION
Birth control has been a human concern for thousands of years; the oldest known medical text, from the 19th-century bc, contains information on contraception. The first contraceptive devices were simple mechanical barriers inserted into the vagina that prevented the male sperm, deposited in the vagina during sexual intercourse, from fertilizing the female ovum. Among the many vaginal preparations that have also been used historically to prevent pregnancy are sea sponges, quinine, rock salt, and alum.
In 1798 the British economist Thomas Robert Malthus predicted that the human species would one day outstrip its capacity to feed itself. In succeeding years, as medical care, nutrition, sanitation, and working conditions improved and the death rate began to drop, more attention began to be paid to contraception. The first organized movement towards that end developed during the 19th century. The pioneer Marie Stopes almost single-handedly, and against powerful opposition, succeeded in promoting public knowledge of, and demand for, contraception.
III CONTRACEPTION WORLDWIDE
Contraception is essential for people to be able to control their fertility. Despite this, religious, moral, political, and individual opposition to contraception remains strong in many countries. According to figures from the United Nations in 2006, there are more than 370 million couples worldwide who lack access to modern contraceptive services, mostly in developing countries, and it is estimated that demand for services will increase by 40 per cent by 2025. This is important, as pregnancy is a major cause of death and disability among women around the globe. There are approximately 210 million pregnancies globally per year and 80 million of these are unplanned. About 600,000 women die every year as a result of pregnancy-related illnesses. Children’s health is also improved through parents’ ability to control their fertility and space births. Some contraceptives (barrier methods) also protect people from sexually transmitted infections (STIs), including the human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS).
People being able to control their fertility is also important, given that global population continues to grow towards a situation whereby people’s material needs will not be able to be met by the finite resources on Earth. According to the United Nations Children’s Fund (UNICEF) in its 1992 annual report, “family planning could provide more benefits to more people at less cost than any other single ‘technology’ now available to the human race”.
IV METHODS OF CONTRACEPTION
A Natural Contraception
Natural contraceptive techniques include abstinence, breast feeding, withdrawal or coitus interruptus, and the rhythm or calendar method.
Abstinence is where a person refrains from vaginal sexual intercourse entirely. Breast feeding can be a reliable method of contraception as long as there is exclusive breast feeding, the mother is amenorrhoeic (not menstruating), and the baby is under six months. Withdrawal is a technique where the penis is removed from the vagina prior to ejaculation. This method can be unreliable as some sperm may be present in secretions from the penis prior to ejaculation (pre-come). The rhythm method is based on abstinence from sexual intercourse on days when fertility is probable, and its effectiveness depends on accurately predicting the times when the woman is ovulating. Prediction is attempted either by monitoring changes in the woman’s basal body temperature that signal ovulation, or by identifying changes in cervical mucus and other symptoms that indicate ovulation, or both.
B Barrier Methods
Barrier methods—physical blocks to sperm entering the uterus—are available for both men and women.
Condoms, or sheaths, are the oldest form used by men, and when used properly (and remaining intact) with each act of intercourse they are 98 per cent effective. With younger and inexperienced users, the failure rate of condoms—and indeed, of most birth-control devices and methods—is higher. Because condoms are inexpensive, easy to use and acquire, do not require medical supervision, and have few side effects, they are currently the most common contraceptive devices employed worldwide.
Unprotected sex is sexual intercourse without a condom, and is also termed “unsafe sex”. Condoms also help to prevent infection by STIs, such as gonorrhoea, Chlamydia, and hepatitis B. The use of condoms is also vital in helping to prevent the sexual transmission of HIV, the virus that causes AIDS.
A female condom (which is inserted into the vagina) was approved for sale in Britain and the United States in 1993-1994. It is the only female-controlled method of contraception which also prevents STI transmission.
Around 1 per cent of women in England use the diaphragm or cap, a shallow hemispherical rubber device that fits over the cervix (neck of the uterus) to prevent the sperm reaching the ovum and fertilizing it. The cap holds a spermicidal (sperm-killing) jelly or cream that immobilizes any sperm that may be present around the edges of the diaphragm. These devices have few side effects and, when used in conjunction with a spermicide with each act of intercourse, their effectiveness is 92 to 96 per cent.
Intrauterine devices, or IUDs, are often T-shaped, but can also be a variety of other shapes, and usually, release small amounts of copper or the synthetic hormone progesterone into the uterus. Their effectiveness ranges from 95 to over 99 per cent. IUDs are thought to work mainly by preventing fertilization, but may also interfere with the implantation of the fertilized ovum into the lining of the uterus. An IUD must be inserted into the uterus by a doctor or nurse, but once inserted it can remain in place for five to ten years. Some women, however, experience increased menstrual flow when using a copper IUD. Women who have the progesterone-releasing IUD often have reduced periods or no periods after 12 months of use.
D Hormonal Methods
Hormonal or chemical methods include “the pill”, contraceptive patches, injections, implants, and hormone-releasing IUDs.
D1 Oral Contraceptives
There are two types of contraceptive pills. The combined pill, or combined oral contraceptive, commonly known as the pill, contains the hormones oestrogen and progesterone. The mini-pill, or progesterone-only pill, contains only the hormone progesterone.
The combined oral contraceptive pill works by altering a woman’s normal hormonal patterns so that ovulation does not occur. The combined pill also causes thinning of the uterine lining (endometrium) and thickening of the cervical mucus, thereby making it resistant to sperm. The pill is 99 per cent effective when taken according to directions, and for a number of years, it was the single most popular form of contraception.
The progesterone in the progesterone-only pill thickens the cervical mucus, preventing the sperm from meeting and fertilizing the ovum. It is 98 per cent effective when used according to instructions.
While concern has often arisen about its safety, the pill is, nevertheless, still the most popular method of birth control in the United Kingdom.
Evidence has been gathered which strongly suggests that women over the age of 35, and particularly women who smoke, should probably not use the combined pill because of the increased risk of blood-clotting disorders such as thrombosis and stroke. Studies thus far have not conclusively linked the use of the pill and a higher risk of the development of breast cancer or cervical cancer, although some research has suggested a possible link. Other research suggests that the chances of ovarian and uterine cancer may even be lowered with its use. Many women notice side effects from pill usage, however, such as changes in mood, as well as positive advantages, such as shorter and lighter periods.
Research is currently underway to develop a male contraceptive, presently in the form of either a combined injection of progesterone and testosterone or a combined delivery of progesterone by a regular pill or injection and testosterone by a permanent patch on the arm or implant under the skin. So far in trials, both methods have proved effective, but it is not expected that a pill will be in commercial production for some years.
Another form of chemical contraception is spermicidal jelly, cream, or foam. Like condoms, spermicides can be used without medical supervision and must be used with each act of intercourse. They have few side effects but are less effective than all other methods.
D3 Injections and Implants
Injections of the hormone progesterone are an effective method of contraception and usually last 12 weeks. There are other preparations that can last for less time than this. It is not reversible in the time period it is being used, and is almost 100 per cent effective.
Implants contain the hormone progesterone and last from three to five years. The implant consists of flexible tubes that release progesterone and which are inserted under the skin of the upper arm. The progesterone makes the cervical mucus thicken, preventing sperm from meeting the ovum.
E Emergency Contraception
Emergency contraception refers to methods that can be used after unprotected sex. These include tablets (the “morning-after pill”) containing progesterone, or oestrogen and progesterone, that are started within five days of unprotected sex. A copper-releasing IUD can also be fitted within five days of unprotected sex.
F Surgical Sterilization
Another form of contraception is surgical sterilization. In women this is accomplished by clipping, tying, or cutting the Fallopian tubes. In men, sterilization is accomplished by a vasectomy procedure—cutting or tying the two vasa deferentia (plural of vas deferens).
Vasectomy is easy to accomplish, with very few side effects and has no effect on male libido or masculinity. It has a failure rate of just 1 in 2,000 procedures. This is in contrast to female sterilization, which requires abdominal surgery to access the Fallopian tubes. This latter procedure does have complications associated with it and is much less effective than vasectomy, with a failure rate of 1 in 200. Both these methods should be considered as permanent and irreversible, as surgery to restore fertility after sterilization is unlikely to be successful.
Marie Stopes International