The planning of the size of a family means how many children a couple wish to have or can afford to have so that they may be able to take care of them properly, educate them well and provide for other facilities. One also has to consider the wider implications of a large family. Each member of the family contributes to the population of the society and country at large. Each person has a role to play in creating an impact on the whole world. With increase in population resources of this earth are bound to deplete rapidly. The environmental quality is going to be affected and all this might spell door for mankind. It is, therefore, extremely important to keep the size of a family to a reasonable limit of two to three. It requires the use of the methods which prevent fertilization of ova.
Fertilization of the egg and its implantation or nidation is referred to as conception or pregnancy. Prevention of conception is called contraception. There are several ways by which conception can be prevented.
1. Natural methods:
If there is no coitus or sexual intercourse, sperms would not be discharged in the vagina and there would be no chance of fertilization of the ovum. The ovum is released from the ovary of woman two weeks (14 days) before the expected date of next menstruation. The date of ovulation is, therefore, in between the two menstruation cycles. If copulation is avoided for a few days i.e., around 14th day after the menstruation of the woman, which is the likely date of ovulation, there will be no fertilization. As usual, the ovum will be released on the expected date of ovulation, and it will come down the oviduct and finally get out of the body in 48 hours of its ovulation. If there is no sexual intercourse during the expected period of ovulation, there is no chance of sperm coming in contact with ovum. This practice of avoiding sexual intercourse during ovulation period is called rhythm method of contraception. Even if there is sexual intercourse, the sperms should not be discharged into the vagina. One recourse may be the withdrawal of penis just before sperms are going to be ejaculated. This is called coitus interrupts.
2. Mechanical Methods:
There are a number of such methods available for use. One of them is to use a rubber tube called condom. This is worn over the penis before sexual intercourse. The ejaculate is collected in this tube, and is not discharged in the vagina. In this method the seminal fluid does not have any contact with the vagina. It also prevents spreading of venereal diseases and AIDS which spread due to the real contact between the genital organs.
A diaphragm or cap can also be applied to the neck of the vagina, i.e., the cervix. This is fitted into the woman by a doctor. Diaphragm does not allow the seminal fluid to go towards the fallopian tube.
Intrauterine device (IUD) or loop is another device which can be used by a woman to prevent conception. IUD is made up of plastic or stainless steel. It is inserted in the uterus. Its insertion causes irritation in the uterus lining. As a result there is a lot of mucus secretion which prevents implantation of the embryo.
3. Chemical Methods:
These methods call for the use of some chemicals which are spermicidal, i.e., which kill the sperms. The vagina can be flushed with such solution immediately after sexual intercourse. It is also called the douche method. The application of spermicidal cream or jelly before intercourse can also prevent fertilization.
Oral contraceptives are tablets which a woman has to take everyday. These are also called birth control pills. Of all the contraceptive measures, oral contraceptive pills are most effective. A classical oral pill contains progesterone-like substance and a small does of estrogen. These compounds are absorbed by the intestine and taken in the blood. They finally reach the hypothalamus of brain and thereby serve to prevent the release of luteinizing hormone (LH). You will recall that LH is responsible for ovulation in the female. The net result of the intake of thee pills is that the ovum is not released from the ovary at all. Since the ovum does not come into the fallopian tube, the question of is fertilization does not arise.
4. Surgical Methods:
Testis is situated in the scrotum. From each testis arises a tube called vas deferens which carries with it the sperms produced by the testis to the urethra. If this tube is tied by a thread, the sperms will knot be able to go past the tied point. This tube can be exposed by a slight incision at the base of the scrotum. This incision and subsequent ligature (tying by thread) of the vas deferens by a surgeon is called vasectomy. In a vasectomised person, sperms are produced but these do not come in the seminal vesicle. When such a person ejaculates, his ejaculate does not contain sperms. In women, ligature of the fallopian tube can be done (tubectomy) to prevent passage of ova down the fallopian tube.