Sex selection and family patterns across Vietnam
In general, while there are many local explanations for the emergence of prenatal sex selection, a more solid interpretative framework points to the combination of three factors: supply, demand and fertility decline. The supply dimension pertains to the introduction of affordable prenatal diagnosis technologies such as ultrasound, which allow parents to opt for abortion according to the gender of the foetus. The demand factor corresponds to the biased gender valuation system, usually manifested by a strong preference for sons over daughters. The preference for male offspring is clearly linked to the preponderance of the patrilineal kinship system and to living arrangements, farm labour, inheritance systems, and support to the elderly. The third factor pertains to the declining fertility level since the proportion of parents with no son automatically increases when the average number of children reduces.