A cultural preference for boys has left more than 63 million women statistically "missing" across India, government officials have said.
The skewed ratio of men to women is largely the result of sex-selective abortions, as well as better nutrition and medical care for boys, according to the government's annual economic survey.
In addition, the survey found that "families where a son is born are more likely to stop having children than families where a girl is born".
Accoridng to scientists statistics indicate that India has 63 million fewer women than it should have.
The birth of a son is often a cause for celebration and family pride, while the birth of a daughter can be a time of embarrassment and even mourning as parents look toward the immense debts they will need to take on to pay for marriage dowries.
Studies have long shown that Indian girls are less well-educated than boys, have poorer nutrition and receive less medical attention. Many women - including educated, wealthy women - say they face intense pressure, most often from mothers-in-law, to have sons.
By analysing birth rates and the gender of last-born children, the report also estimated that more than 21 million Indian girls are not wanted by their families.
"The challenge of gender is long-standing, probably going back millennia," wrote the report's author, chief economic adviser Arvind Subramanian, noting that India must "confront the societal preference for boys".
The report also noted that increasing wealth does not mean an end to male preferences among families, with some comparatively wealthy areas, including New Delhi, faring worse over the years.
Many of the best scores for women's development, the report noted, were in India's north-east - "a model for the rest of the country" - a cluster of states on the edge of the country where most people are ethnically closer to China and Burma, and where some do not regard themselves as Indian.
- Press Association