Contraception: Indications and Types

Contraception refers to the collection of practices involved with the process of preventing pregnancy in a woman to help her exercise control over her reproductive life. There are many methods of contraception which have evolved over the years with varied rates of success at preventing pregnancy.

Indications of Contraception

• Desire to postpone or space pregnancy.
• Currently taking medications that may be harmful to a growing fetus.
• Patient with a medical condition which can worsen during pregnancy. This includes certain heart and lung disorders.
• For protection from sexually transmitted diseases: The barrier methods are the only ones effective
• Polycystic Ovarian Syndrome: This is a condition marked with imbalances in the sex hormones. The oral contraceptive pill exerts control over the sex hormone axis helping to normalise menstrual cycles

A summary of the available methods with their success rates at preventing pregnancy have been enumerated below

What are Natural Methods of Contraception?

These are archaic methods which are however still used by couples who wish to avoid using medicines for contraception. They have a high failure rate.

• Rhythm method: In which the woman and the couple would avoid sexual intercourse on fertile days of the monthly menstrual cycle. There is a 24% failure rate.
• Withdrawal: This involves removal of the penis from the vagina just prior to ejaculation. This has a failure rate of 22%

What are Barrier Methods of Contraception?

This prevents the female egg from coming in contact with the sperm, thereby preventing fertilisation of the egg.

• Male Condoms: these are very commonly used and are the only method of contraception which also prevents the transmission of sexually transmitted infections (STIs). When used correctly it has a failure rate of only 2%, however improper use can increase this to 18%. Rarely, individuals who have latex allergy can have allergic reactions. Several latex free options are also available.
• Female condoms: these are dome-shaped and are placed within the vagina to protect the opening of the cervix. With appropriate use, it has a failure rate of 5% only, but can have up to 20% failure otherwise. This is cumbersome to use and does not offer any added advantage of preventing STIs.

What are the Hormonal Methods of Contraception?

• Oral contraceptive pill (OCP) or just called the pill is among the most effective means of preventing pregnancy in women, with a failure rate of only 0.3% with accurate use. This is a medication containing progesterone alone or in combination with estrogen. These sex steroid hormones are at a low level, which is adequate to suppress the intrinsic hormonal variations thereby preventing ovulation or the release of the egg. OCPs have helped empower woman as they were given the opportunity to take control of their own contraception. The two major types are:
  • Combined low dose estrogen and progesterone pill
  • Progestin-only pill (POP)

It is important to bear in mind that these pills need to be taken every day without any change in schedule to get the best contraception rates. In case of missing a dose, alternative barrier methods of contraception must be used to prevent pregnancy. Avoid using OCPs if you smoke as there is an elevated risk for clot formation in the veins. Individuals with a history of breast or endometrial cancers are also advised against taking OCPs.

• Hormonal implants: These are small drug-loaded structures that are inserted into the subcutaneous tissue. They work by releasing hormones into the body similar to OCPs but they last for several weeks to months and thus do not require scheduled drug intake. The failure rate is as low as 0.05%
• Injectable hormones: medroxy progesterone inserted into the subcutaneous tissue as a depot that is effective for 3 months with a failure rate of 0.2%
• Hormone releasing rings or patches such as nuvaring and Evra patch can be alternate methods which rely on changing hormone balance in the body. They have a failure rate of 0.3%
• Intrauterine Contraceptive Devices (IUCDs): These are objects which are placed within the uterus through the vagina and cervix. These methods are very effective at preventing pregnancy and depending on the type can be left in place for 5 to 10 years. They cause a local inflammatory reaction in the uterus preventing the implantation of a fertilized egg into the uterus. These are ideal for spacing children although can be used by any woman at any time. There are several side effects of reported bleeding, vaginal discharge and abdominal pain. The two major types of IUCDs are
  1. Copper releasing IUCD
  2. Progesterone releasing IUCD (Mirena) : this has an added benefit of reducing the level of bleeding during menses and is thus used frequently to control heave menstrual bleeds.

What are Terminal Methods of Contraception?

These are irreversible procedures which are done to sterilize the person to prevent pregnancy

• Female sterilisation or tubal ligation: this is a minor operation in which the fallopian tubes (tubes through which the eggs gets passed from the ovary to the uterus) are tied up or clamped. The failure rate is 05% and is a result of improper ligation or reattachment of the tubes after the procedure.
• Male sterilization or vasectomy is a very simple procedure where the vas deferens (the tube that carries sperm from the testes) is cut and tied off. It is important to keep in mind that following a vasectomy, residual sperms linger in the rest of the reproductive tract for 3 months. During this time additional methods of contraception are to be used.

What are Spermicidal Jellies and Sponges?

All the methods described above can be used along with spermicides which kill the sperm attempting to enter the cervix. The failure rate when used lone is about 18%.

The choice of contraception is determined on a case-by-case basis. It is best to consult your Family practitioner or Gynaecologist before initiating any particular method to help fully understand if it would indeed be the right method for you and to explore different options.

References:

• Choosing a Birth Control Method: Contraceptive Failure Rates: Table [Internet]. [cited 2018 Jul 5]
• Contraception | Reproductive Health | CDC [Internet]. 2018 [cited 2018 Jul 5]