Fertility  In the 1970s, the government of Bangladesh declared population as the number one problem of the country. Since then, many programmes have been undertaken by government and non-government organisations as well as by private and international agencies to address the issue. A major activity undertaken is the establishment of a well-designed network for providing door-to-door family planning services by female field workers, known as family welfare assistants (FWAs). The most notable achievement is a remarkable decline in fertility in the last two decades. The Bangladesh family planning programme is now considered a model for developing countries.

In 1901, this part of undivided Bengal had a population of less than 30 million. The annual growth rate was less than 1% up to 1951, when the size was about 44 million. The population started to grow at a high rate since the 1950s. The rate was all-time high (about 2.5%) in the 1960s and in the l970s. The growth rate started to decline in the 1980s, and is now about 1.6%. In 1999, the country had a population of about 130 million.

Table Population Size, CBR, CDR, Natural Growth Rate and Annual Growth Rate (1901-1991)

The fact that the population growth at the beginning of the century was much lower than at the present does not mean that fertility at the beginning of the century was lower than what it is now. The growth of a population depends on fertility, mortality, and migration. Muslims constitute more than 85% of the total population of Bangladesh and the international migration of Muslims living in Bangladesh was almost absent before the independence of the country in 1971. And even since then, the annual number of international migration of Muslims has been very small. On the other hand, the growth of the minority community, represented mostly by Hindus, has been very much determined by their migration to India. At the beginning of this century, the proportion of Hindu population was 33%. This proportion came down to 22% in 1951 as a result of out-migration in large numbers to India after the Partition of Bengal in 1947.

The migration continued throughout the Pakistan period, and the proportion of Hindus in the country's total population came down to 14% in 1974. In the 1991 Population census, the proportion of Hindus came down further to 11%. Although a small part of this decline in the proportion of the Hindus may be attributed to a lower fertility among them compared to Muslims, out-migration of this community to India continues to be the main reason of this decline. Since Hindus constitute a small part of the total population, their migration does not have a large effect on the overall growth of population in the country.

Fertility and mortality have, therefore, been the main factors for the population growth of Bangladesh. Fertility has different measures. The most simple and well-known measure is the crude birth rate (CBR) defined as the number of births in a year per 1,000 mid-year population. This measure is crude, because it does not make any allowance for age and sex. CBR in Bangladesh was more than 50 per 1,000 population until the mid-1960s. It declined during the war of liberation in 1971 and during the famine of 1974-1975. Since then, the declining trend of the CBR has been continuing till now, except for a slight rise in 1976. The present CBR is about 26. The difference of the crude death rate (CDR), defined as the number of deaths in a population in a year per 1,000 population, from the CBR is called the natural growth rate ie, the growth rate without the influence of migration. This growth rate was quite low up to the early l950s, but started to increase since then mainly as a result of the decline in the CDR.

A much more refined fertility measure, widely used by population scientists, is the total fertility rate (TFR). It is an age-sex-adjusted measure of fertility, which takes the account of age details within the childbearing age. The TFR states the number of births a woman would have if she experienced a given set of age-specific birth rates (given by women of different ages in a specific year) throughout her reproductive span. This rate was more than 6 until the 1970s, but started to decline since then and came down to 3.3 in the mid-1990s. If the TFR in a population is close to 2, the population is said to be in the replacement level of fertility, which is a desire of population planners and policy-makers of most developing countries. Important among the factors that determine fertility in Bangladesh are the women's education and empowerment, occupation of husbands, residence (rural vs urban), possession of items and religious beliefs and norms. Education, however, cannot directly affect fertility. It is possible that an educated woman gets married at a higher age and/or uses contraception more frequently. In fact, a socioeconomic, cultural, or environmental variable must work through one or more behavioural or biological variables, such as contraceptive use, frequency of intercourse, abortion, and lactation infecundability. These intermediate variables explain more than 95% of the fertility variations in different countries of the world.

The speed of decline in fertility in developing countries including Bangladesh today is much more than that observed in developed countries during the demographic transition. Family planning programmes have played a significant role in reducing fertility in developing countries, especially in Bangladesh. In the early 1970s, the contraceptive prevalence rate (CPR) in Bangladesh was about 5%, and the TFR was close to 7. At present, the CPR is about 50% and the TFR has come down to about 3.

During the thirty years after independence of Bangladesh, there had been some significant changes in the socioeconomic, cultural, and environmental situation of the country. People now have a perception about the desired family size and thanks to the family planning programmes, eligible couples have their fertility targets. A change in socioeconomic status, particularly in women's education, is expected to bring about a further change in the desired family size. [Radeshyam Bairagi]

Infertility the inability or diminished ability to produce offspring. In fact, the phenomenon indicates a woman's inability to conceive and bear a living child or a man's inability to impregnate a woman. From the medical view point, a couple is considered infertile if pregnancy does not occur within one or two years of unprotected intercourse. Demographers often term a couple infertile if no pregnancies or live births are reported within a certain number of years of unprotected sexual union. For women, failure to bear children often leads to social disgrace and sometimes to divorce.

The extent of infertility varies among countries and even among different populations within a country. WHO estimates that there are 60-80 million infertile couple worldwide. According to the World Fertility Survey Report (1974-79), 2.2% of the sampled 826 women in Bangladesh suffered from infertility. The infertility rate was found 2.8% in Pakistan (sample 990), 3.1% in Nepal (sample 988), and 4.3% in Indonesia (sample 1728).

Little is known about the causes of infertility in Bangladesh. A 14 years data analysis from an infertility clinic shows that about 61% of the cases are without any detectable clinical reason; ovulatory disturbances were responsible for about 30%, and the rest had tubal or other problems. A study of 275 men attending an infertility clinic at Dhaka with their wives recorded that 29% of men were probably infertile. A common cause of infertility of women is the tubal obstruction or pelvic adhesions due to infectious diseases including sexually transmitted diseases (STDs). In men, infertility is often caused by either blockage of sperm ducts or disorder in sperm production. The other causes that may lead to male and female infertility include infectious diseases like tuberculosis, leprosy, mumps; parasitic diseases such as malaria, filariasis, schistosomiasis; malnutrition; excessive smoking and alcohol drinking; therapeutic radiation; ovulation disorders; and endometriosis. Infertility is much higher in women with endometriosis.

Infertility therapy is often unsuccessful and only about a quarter to half of the treated couples achieve a live birth. In addition, most infertility treatments are sophisticated and expensive, and is out of reach of the majority of infertile couples. [SM Humayun Kabir]