This article is about the methods of diagnosis of the child selection of the sex of offspring. For the evolutionary concept, see sexual selection. Sex selection is the attempt to control the sex of the offspring to achieve a desired sex.
It can be accomplished in several ways, both pre- and post-implantation of an embryo, as well as at childbirth. It has been marketed under the title family balancing. According to the United Nations Population Fund, the reasons behind sex selection are due to three factors and provide an understanding for sex ratio imbalances as well as to project future trends. Low fertility which increases the need for sex selection by reducing the probability of having a daughter in smaller families. Local fertility restrictions and spontaneous rapid fertility decline below replacement levels tend to compel parents who want both a son and a small family size to resort to sex selection.
In many cultures, male offspring are desired in order to inherit property, carry on the family name and to provide support for parents in old age. In countries such as India, China, Indonesia and Nepal sons have been favored over daughters. A 2009 study at the University of Ulster found that having sisters, as compared to brothers, can enhance the quality of an adult’s life. The one child policy in China has contributed to the imbalanced sex ratios. There is a preference of parents to have a son over a daughter in many countries. This can be observed through sex ratios of children in various countries.