Birth Control The term birth control refers to the volitional (自觉的) control of the number and spacing of children in a family. It encompasses the wide range of rational and irrational methods that have been used in the attempt to regulate human fertility, as well as the response of individuals and of groups within society to the choices offered by such methods. Birth control has been and remains controversial. The U. S. reformer Margaret Sanger coined the phrase in 1914～1915 and, like the social movement she founded, the term has been caught up in a quest for acceptance, generating many synonyms, family planning, planned parenthood, responsible parenthood, voluntary parenthood, contraception, fertility regulation, and fertility control. Human reproduction involves a range of activities and events, from sexual intercourse through birth, and depends as well on a series of physiological interactions, such as the timing of ovulation within the menstrual cycle. The visible events are central to the transmission of life and have been subject to social and religious control. The invisible factors in human reproduction gave rise early on to speculation and in modern times have become the topic of scientific investigation and manipulation. New knowledge relevant to birth control has diffused at different rates through various social groups and has not always been available to those with the greatest need. Hence, the conflicts and controversies surrounding birth control have been complex and impassioned. The disagreement over birth control arises in part from the debate over what is natural and what is artificial (and, to some, unacceptable). In 1790 a Venetian monk, Gianmaria Ortis, concluded that human population growth could not continue indefinitely. Malthus' work a few years later stimulated more discussion and also provided the intellectual clue that inspired Charles Darwin's theory of biological evolution through the survival of the fittest. In 1798 Thomas Malthus wrote An Essay on the Principle of Population. It posed the conundrum (大难题) of geometrical population growth's outstripping arithmetic expansion in resources. The debate about human numbers remained academic, however, until the 1950s, when a surge in population occurred as a result of the comparative peace and prosperity following World War Ⅱ. In Malthus' time world population was under 1,000,000,000, and when Sanger and Stopes opened the first birth control clinics population was still less than 2,000,000,000. In 1960 global population surpassed 3,000,000,000, and the next 1,000,000,000 was added in a mere 15 years. In the 19th century the population of industrialized nations rarely grew by more that 1 percent per annum, but in the 1960s and '70s many developing countries exploded at a rate of 2 to 3 percent per year. Rapid population growth has several economic consequences. It requires heavier investment in education, health, and transport merely to maintain these services at their previous level yet, the working population has a higher burden of dependence to support, making both individual and national saving more difficult. Although population growth is not the only problem dividing rich and poor countries, it is one important variable that has widened the gap in growth in per capita income between developed and developing nations. Advocates of birth control see it as a means to prevent the personal and social pressures that result from rapid population growth. There is a marked relationship between patterns of reproduction and the risk of death to the mother and her child. Maternal deaths and infant mortality are up to 60 percent higher among girls under 15 than among women who have a child in their early 20s. The risk of death to the mother and her child rises again in the second half of the 30s. Maternal and infant mortality is lowest for the second and third deliveries.