4.15. Since in all societies discrimination on the basis of sex often starts at the earliest stages of life, greater equality for the girl child is a necessary first step in ensuring that women realize their full potential and become equal partners in development. In a number of countries, the practice of prenatal sex selection, higher rates of mortality among very young girls, and lower rates of school enrolment for girls as compared with boys, suggest that "son preference" is curtailing the access of girl children to food, education and health care. This is often compounded by the increasing use of technologies to determine foetal sex, resulting in abortion of female foetuses. Investments made in the girl child's health, nutrition and education, from infancy through adolescence, are critical.