Contraceptive methods are preventive methods which help women to avoid unwanted pregnancies.
Classification of contraceptive methods
A TEMPORARY METHODS (Spacing methods)
1 Barrier methods: Physical methods Chemical methods Combined methods
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2. Intra – Uterine devices
3. Hormonal methods
4. Post conception al methods
5. Miscellaneous
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B. PERMANENT METHODS (Terminal methods)
1. Male sterilization
2. Female sterilization.
TEMPORARY METHODS
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Barrier Methods
Barrier or occlusive methods suitable for both men and women are available. The aim of these methods is to prevent the sperm meeting the ovum. The barrier methods are further classified as a. Physical methods b. Chemical methods c. Combined methods
PHYSICAL METHODS (Mechanical methods)
They include 1. condom 2. diaphragm 3. Vaginal sponge.
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Condom
It is a male contraceptive. It is made tromp latex. In India, it is commonly known by the trade, name Nirodh. It is fitted on the erect penis before intercourse.
Mechanism: It acts by preventing deposition of semen in the vagina.
Precautions:
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1. It must be free from tears and leaks. So it must be tasted by filling with water.
2. It must be discarded after single use.
3. After intercourse, it must be carefully removed from vagina to prevent spilling of semen into the vagina.
Advantages:
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1. Inexpensive, safe, easy to use and reliable.
2. Affords protection against STD and AIDS.
3. No side effects
4. Light, compact and easily disposable.
Disadvantages:
1. Due to incorrect use, it may slip of or tear during coitus.
2. It interferes with sex sensation locally.
2. Diaphragm
It is a vaginal barrier used by women. It is a shallow cup made of synthetic rubber or plastic material. It has a diameter of 5 – 10 cm. It has a flexible rim made of spring or metal. It is inserted in
Advantages:
Total absence of risks and medical contraindications. Disadvantages:
1. Initially, a physician or a trained person is required to demonstrate the method of insertion.
2. Privacy is required for insertion.
3. If left in the vagina for prolonged period, it may produce a toxic shock syndrome.
3. Vaginal sponge
It is marketed under the trade name Today. It is a small polyurethane sponge measuring 5 x 2.5 cm. It is saturated with a spermicide, nonoxynol – 9.
CHEMICAL METHODS
They make use of chemical spermicides. They are used in the form of:
1. Foams (foam tablets, foam aerosols)
2. Creams, pastes and jelly’s
3. Suppositories4. Soluble films
Mechanism:
These preparations contain surface active agents which attach to the spermatozoa. They inhibit oxygen uptake and kill the sperms.
Disadvantages:
1. High failure rate
2. Must be used immediately before intercourse.
3. Mild irritation, burning and messiness.
INTRA – UTERINE DEVICES (IUD)
Historical aspects
Arabs were the first to use the principle in camel. Introduction of small stones into the uterus of camels prevented conception. In 1909, original devices made of silkworm gut was used. In 1929, Gutenberg, a Gynecologist used an IUD made of silver.
Types of IUD
1. First generation IUDs Lippi’s loop
2. Second generation IUDs : Copper T
Copper 7 Nova T
Multiload devices.
3. Third generation IUDs Progestasert
First generation IUDs
They are inert, non – medicated devices made of polyethylene or other polymers. They appeared in various shapes and sizes like loops, spirals, coils and rings. Lippies loop is the commonly used device.
Lippi’s loop: It is a double – S shaped device made of polyethylene which is non – toxic, non – reactive and durable. It contains a small amount of barium sulfate which allows X-ray examination. Also it has attached threads (tail) which project into the vagina. The feeling of thread in the vagina assures that the loop is in its place.
Advantages
1. Simple and easy insertion
2. Inexpensive
3. Reversible method
4. Does not interfere with sexual pleasure
Disadvantages
Needs a trained person for insertion
Needs adequate follow up
Should be replaced periodically (2-4 years)
Rarely it can produce cancer of uterus or fibroid
Second generation IUDs
The second generation IUDs are copper containing devices. Older devices are copper – 7 and copper T – 200. Newer ones are Nova T and Multiload devices.
Mechanism
They act by releasing copper into he uterus. Copper enhances cellular response in endometrium and alters the composition of cervical mucosa.
Advantages
1. Low expulsion rate
2. Lower incidence of side effects like pain and bleeding
3. Easier to fit even in nulliparous women
4. Increased contraceptive effect
5. Effective as post – coital contraceptive if inserted within 3 to 5 dabs after intercourse
Third generation IUDs
These devices act by releasing a hormone. The currently used device is Progestasert. It is a T – shaped device filled with progesterone, a natural hormone. It acts by releasing 65 micrograms of the hormone daily in the uterus. It has a direct local action on the cervical mucosa and sperms. Since the hormone is gradually depleted, regular replacement of the device is necessary.
Another similar hormonal device is a T- shaped IUD which releases levonorgestrel. It has an effective life of 5 years.
HORMONAL CONTRACEPTIVES
Hormonal contraceptives are the most effective spacing methods of contraception. These hormonal contraceptives can be administered orally by injection or as implants. But oral pills are more commonly used.
Composition
These contraceptives contain a combination of both estrogen and progestogen or prostogen only.
Mechanism
These contraceptives suppress the regular monthly peaks of pituitary and ovarian hormones which is necessary for ovulation. So ovulation does not occur
Classification of Hormonal contraceptives
Oral pills Combined pill
Progestogen-only pill (POP) Post-coital pill Once-a-month pill Male pill
ORAL PILL (Oral contraceptives)
1. Combined Pill
These pills contain 30 to 35 micrograms of a synthetic estrogen and 0.5 to lmg of a progestogen. One pill daily is given orally, for 21 days beginning on the 5th day of menstrual cycle. A break of 7 days is given and menstruation occurs during this period. The 1st day of bleeding is taken as the 1st day of the next menstrual cycle.
The department of Family Welfare (Ministry of Health and Family Welfare, Gov., of India) has made available two types of pills:
1 .Mala – N which contains
Norethisterone acetate – 1.0 mg Ethyl estradiol – 0.03 mg.
2. Mala – D which contains
D – norgestrol – 0.50mg
Ethyl estradiol – 0.03 mg.
2. Progostogen-only pill (POP)
It is also called as “maniple” or “microfiche”. It contains only progostogen (which is norethisterone or levonorgestrel). It is not very popular because of poor cyclic control and increased pregnancy rate.
3. Post – octal – pill (or morning after)
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Injectable Sub dermal implants Vaginal rings |
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Depot formulations (slow release) |
It is recommended within 48 hours of an unprotected intercourse. It contains either a high dose of oestrogen or double the dose of standard combined pills (i.e. 2 pills).
4. Once-a-month pill
It contains a long acting estrogen (quinestrol) in combination with a short acting progestogen. It is not popular since it has a high pregnancy rate and bleeding is irregular.
5. Male pill
It contain Gossypol which is a derivative of cotton seed oil. it acts by decreasing sperm production and sperm count. It is not widely used since it is highly toxic and produces permanent azoospermia.
Adverse effects of oral contraceptives
1. Cardiovascular: Myocardial infraction and thromboembolic complications.
2. Carcinogenesis: Cancer of breast and genitalia.
3.. Metabolic: Hyperglycemia and glycosuria, at hero sclerosis and elevation of blood pressure.
4. Liver disorders: Hepatocellular adenoma and jaundice.
5. Other effects: Barest tenderness, weight gain, headache, migraine, nausea and vomiting.
Advantages
1: Easy to use by oral route 2. Almost 100% effectiveness
•3. Non-contraceptive benefits like protection from breast disorders, ovarian cyst/cancer, iron deficiency anemia and pelvic inflammation.
Disadvantages
1. Cost is prohibitive and so the government has sub sidised it and also supplies free of cost.
2. Side effects and also contraindications.
3. Reduced breast milk production
4. Return to fertility may be delayed.
DEPOT FORMULATIONS
They include injectable contraceptives, sub dermal implants and vaginal rings.
Injectable contraceptives
Two drugs are available. They are:
1. DMPA (Depot-medroxyprogesterone acetate)
2. NET-EN (Nor- ethisterone enanthate)
They are progostogens and require administration once every 3 months.
Mechanism: The active compound is slowly released which produces 1. inhibition of ovulation 2. thickening of cervical mucus 3. production of a thin atrophic endometrium.
Contraindications
1 Cancer of breast or genital tract 2. Unexplained vaginal bleeding.
Sub dermal implants
The available drug is Norplant. It contains levonorgestrel. It consists of 6 hollow slapstick capsules each containing 36 mg of levonorgestrel. These capsules are implanted below the skin of forearm or upper arm. They provide effective contraception for 5 years. The contraceptive effect is reversible on removal of the capsules. Disadvantages are 1. irregularities of menstrual bleeding 2. surgical procedures are necessary for insertion and removal.
Vaginal rings
They contain levonorgestrel. It is slowly absorbed through the vaginal mucosa. It bypasses the digestive system and liver. So an effective concentration is available even with a lower dose.