Reproductive Health, Contraception, and STIs

Reproductive health means physical, mental and social well-being in matters related to the reproductive system; it includes safe contraception to prevent pregnancy and the prevention and treatment of sexually transmitted infections (STIs). In brief: barrier methods such as condoms prevent pregnancy and also reduce the risk of most STIs, hormonal methods such as the pill prevent ovulation, and only abstinence is fully effective against both pregnancy and STIs. Many STIs show no symptoms, so regular testing matters.

This article gives general health education at a school level. It is not medical advice, and anyone with questions about their own health should speak to a doctor, nurse or sexual health clinic. The guide explains the aims of reproductive health, how contraception works, how effective the common methods are, how STIs spread and are prevented, a worked example on effectiveness and common misconceptions.

What is reproductive health?

The World Health Organization describes reproductive health as a state of complete physical, mental and social well-being in all matters relating to the reproductive system, and not only the absence of disease. It includes the ability to have a satisfying and safe sex life, the freedom to decide if and when to have children, access to information and health services, and safe pregnancy and childbirth.

Good reproductive health depends on accurate knowledge, access to health care, good hygiene, regular check-ups and respect in relationships. It includes screening for conditions such as cervical cancer, which can be detected early with regular tests, and vaccination against the human papillomavirus (HPV), which causes most cervical cancers.

How does contraception work?

Contraception, or birth control, prevents pregnancy. Methods work in one of four ways: they stop sperm from reaching the egg, stop ovulation, prevent implantation or permanently stop gametes from meeting.

Barrier methods

Male condoms (a thin sheath worn on the penis) and female condoms (a pouch placed in the vagina) form a barrier that stops sperm from entering the vagina. They are the only methods, other than abstinence, that also give good protection against most STIs, including HIV. The diaphragm and cap are placed over the cervix and used with spermicide, but they do not protect well against STIs.

Hormonal methods

The combined pill contains estrogen and progesterone-like hormones, and the mini-pill, implant and injection contain progestogen only. They mainly prevent ovulation and thicken cervical mucus so that sperm cannot get through. They are very effective when used correctly, but offer no protection against STIs, and some women have side effects. They require a prescription in many countries.

Intrauterine devices (IUDs)

A small T-shaped device is placed in the uterus by a health professional. Copper IUDs release copper ions, which are toxic to sperm and prevent implantation. Hormonal IUDs release progestogen. They work for several years and are among the most effective reversible methods.

Surgical methods

Sterilization is intended to be permanent. In vasectomy, the sperm ducts of a man are cut or sealed. In female sterilization, the oviducts are blocked or cut. Both are very effective.

Natural methods and emergency contraception

Fertility awareness methods track the signs of ovulation to avoid intercourse on fertile days. They require care and are less reliable. Emergency contraception, such as a pill taken within a few days of unprotected intercourse or a copper IUD, can reduce the chance of pregnancy but is not meant for regular use. Abstinence, not having sex, is the only method that is 100 percent effective.

Contraceptive methods compared

These figures are approximate values quoted by health agencies, and they vary between sources and studies. “Typical use” includes human error, and “perfect use” gives lower numbers: about 2 for condoms and 0.3 for the pill.

What are sexually transmitted infections?

STIs, also called sexually transmitted diseases, are infections that spread mainly through sexual contact, including vaginal, anal and oral sex. Some can also spread from mother to baby during pregnancy or birth, or through blood.

• Bacterial STIs: chlamydia, gonorrhea and syphilis. They can be cured with antibiotics, but untreated infections can cause pelvic inflammatory disease and infertility. Antibiotic-resistant gonorrhea is a growing concern.
• Viral STIs: HIV, genital herpes, hepatitis B and HPV. Viruses cannot be treated with antibiotics. Antiviral drugs can control HIV and herpes, but they cannot cure them. Vaccines exist for hepatitis B and HPV.
• Parasitic STIs: trichomoniasis and pubic lice, treated with specific drugs.

HIV (human immunodeficiency virus) attacks the helper T cells of the immune system. Without treatment, it can lead to AIDS, in which the immune system is so weakened that serious infections occur. With modern antiretroviral therapy, people with HIV can live long and healthy lives, and effective treatment reduces the virus to levels at which it cannot be passed on to partners.

How can STIs be prevented and treated?

• Use condoms correctly and consistently.
• Limit the number of partners, and talk openly with partners about testing.
• Get tested regularly, since many STIs have no symptoms. Early treatment prevents complications and further spread.
• Get vaccinated against HPV and hepatitis B.
• Do not share needles.
• Contact tracing: partners of an infected person should be informed and tested.

Worked example: understanding effectiveness rates

Suppose a method has a typical-use failure rate of 13 pregnancies per 100 women per year, as for condoms in the table. What does this mean for a group of 500 women, and over two years?

1. One year, 500 women: 13 ÷ 100 × 500 = 65 pregnancies expected.
2. Probability of no pregnancy in one year: 1 − 0.13 = 0.87 (87 percent).
3. Probability of no pregnancy in two years: assuming that the rate stays the same and the years are independent, 0.87 × 0.87 = 0.757, which is about 76 percent. So the chance of at least one pregnancy in two years is about 24 percent.
4. Compare with the implant: with a failure rate of 0.05 per 100 (0.0005), the chance of no pregnancy in two years is 0.9995² ≈ 0.999, or 99.9 percent.

The calculation shows why effectiveness differences accumulate over time. Real couples vary, and the failure rate tends to be lower in people who use a method consistently and correctly. The figures are examples, not predictions for individuals.

How have attitudes and methods changed?

People have used methods of birth control for thousands of years, including condom-like sheaths and herbal methods. Margaret Sanger and Marie Stopes opened clinics in the early twentieth century to give women information. The contraceptive pill became available in the 1960s and had a large impact on family planning. Penicillin made syphilis curable in the 1940s. HIV was identified in 1983, and effective combination therapy became available in the mid-1990s.

Which misconceptions are common?

Mistake 1: Believing that the pill protects against STIs

Hormonal methods prevent pregnancy only. Condoms are needed to reduce STI risk.

Mistake 2: Thinking that a person who looks healthy cannot have an STI

Many infections have no symptoms. Testing is the only reliable way to know.

Mistake 3: Believing that pregnancy cannot occur the first time or during menstruation

Pregnancy can occur at any time, and sperm can survive for several days, so ovulation can follow soon after a period in short cycles.

Mistake 4: Using two condoms or reusing a condom

One new condom per act, used correctly, is most effective. Two at the same time increase friction and the chance of tearing.