The availability and application of safe and modern methods of contraception have allowed women to avoid or decrease the number of unplanned, teenage pregnancies. Birth spacing of a minimum of 2 years is recommended by doctors as a minimum gap that should be maintained to keep the mother healthy. Conception can be avoided by various methods which are currently available and each of the methods has its advantages and limitations. Some methods are better suitable for younger women while some are more suitable for slightly older people who have completed their families.
Before one considers a birth control method best suitable for them, they need to consider its effectiveness in preventing pregnancy, its side effects, its advantages, and disadvantages over the other methods. A method of evaluating each contraceptive method is considering its ‘Pearl index’. It is the failure rate expressed in hundred women-years (HWY) and is calculated by dividing the number of unintended pregnancies by ‘number of months of exposure to pregnancy’ multiplied by 1200. According to the pearl index, the highly effective methods of contraception include Tubal ligation/ vasectomy and combined oral contraception. The methods with the highest failure rates are coitus interuptus and the vaginal foam and creams if used alone.
Contraception methods can be divided into 2 categories, Reversible methods, and Irreversible methods. Reversible methods include the following; Periodic abstinence, Coitus interuptus, condoms for men, Barrier methods for women (including condoms and diaphragms), hormonal contraceptives, and intrauterine devices. The irreversible methods include Vasectomy in males and tubal ligation in females.
Reversible methods
Periodic abstinence
In this method, couples are to abstain from sexual intercourse between the woman’s fertile periods. The fertile period is 14+ – 3 days from the start of a woman’s menstrual cycle. This type of method has a very high failure rate. And is hugely dependant on the male partner’s cooperation in the matter.
Coitus interuptus
The coitus interuptus or withdrawal method is one of the oldest methods of contraception. It is hugely dependant on the male partner’s identification of the pre-ejaculatory phase and his effectiveness in withdrawal of the penis before ejaculation. Due to the risks in the timing involved and also because some sperms are present in the lubricating fluid secreted before ejaculation, this method also has a high failure rate and its use is on the decline. (Oats J, 2005).
Male Condoms
A barrier method for men, the condom is the most frequently used contraceptive used nowadays. It has the advantage of being cheap, easily available, and requires almost no time to be properly placed. An added advantage of this method is that male condom are the only contraceptive methods that prevent transmission of sexually transmitted diseases. The male just has to wear the condom before the sexual act. This method is highly effective with a very low failure rate, especially when used in combination with spermicidal agents. It has the disadvantage in that it can break in between the act and this can lead to sperm spillage. But this is a rare occurrence.
Barrier methods for women (cervical cap and Vaginal diaphragm)
The vaginal diaphragm and the cervical cap both are either plastic or rubber dome-shaped apparatuses with a spring circular rim. The diaphragm is easier to use. Once the correct size suitable has been determined by the doctor, the woman can manually insert the diaphragm diagonally across the vagina using the index and the middle fingers. This method requires practice to perfect. It has the disadvantage that it does not protect against most STDs. If used with nonoxynol-9-spermicidal cream, it is known to destroy HIV viruses to some extent. The effectiveness of this method in preventing conception is uncertain. The cervical cap is placed using the same method as the diaphragm but requires a small-sized healthy cervix to work properly. (Oats J, 2005).
Hormonal contraceptives
Hormonal contraceptives either contain estrogen and progesterone combined or progesterone alone. These work as estrogen suppresses the follicle-stimulating hormone (FSH) secretion and decreases LH secretion thereby preventing ovulation from occurring. The progesterone further prevents the release of LH and also changes the mucus consistency of the cervix making it impenetrable by the sperms. The advantage of these is that progesterone allows withdrawal bleed. This is an effective way of contraception and is easy to use as the hormones either come in the form of oral pills or injectables. Benefits of this method include reduction of menstrual cycle disorders, reduction in pelvic inflammatory diseases, no need for insertion of foreign objects into the vagina which can risk irritation and inflammation. Other non-contraceptive benefits include a reduction in the incidence of various carcinomas of the breast, ovaries, and uterus. Disadvantages include pulmonary embolism, deep vein thrombosis in rare instances. Common side effects include acne, chloasma, mild increase in blood pressure, increase vaginal secretions; headaches, etc. combined contraceptive pied to be taken daily for 25 days, and then a 5-day gap is given to allow for breakthrough bleeding. Contraindications include hypertension, hyperlipidemias, estrogen dependant cancer, acute liver disease. (Hales, 2008).
Progesterone only contraceptive is used when combined pill is contraindicated or for breastfeeding mothers. It is available in the form of sub-dermal implants or injectables. The administration is required once every 2 to 3 months. They have a disadvantage in that, in the first 4 to 6 months menstruation may be irregular or the person may go through an ammonia phase.
IUDs Intrauterine devices
The 2 types are currently in use are the Copper T and the Levonorgestrel IUD. They are placed into positions in the females by physicians. They are usually recommended for females in their 40s, these devices work by incapacitating the sperms making them unsuitable for fertilization. They have a failure rate of only one percent. They have the advantage in that if no complications or side effects arise, they can prevent pregnancy for 3 to7 years. The disadvantages associated include perforation of the viscera during insertion, displacement from position and expulsion, allergic reaction of the body to the device and the resultant inflammation, and lastly pelvic inflammatory diseases. (Hales,2008).
Irreversible methods
Vasectomy and tubal ligation
It is recommended for people who have completed their families and do not plan to have any more children. In both procedures, the pathways of the gametes is disrupted by the surgical dissection and tubes in males and females respectively. It has the advantages of being permanent and the disadvantages of the risks that come with all invasive procedures which include pain tenderness in the initial days, risks for infection.
References
Oats J, Abraham S. Fundamentals of Obstetrics and Gynecology. Toronto: Elvsevier Mosby, 2005.
Hales, Diann. An Invitation to Health. Wadsworth, 2008.