The sex ratio at birth (SRB) in India has become more masculine in the recent decades. The imbalance in sex ratios stems from strong son preference combined with declining fertility,
and the availability of and access to sonographic scanning during pregnancy. The practice of gender biased sex selection continues even though India has enacted laws banning the use of pre-natal diagnostic techniques for sex detection. The instances of gender biased sex selection are obviously not recorded but the numbers of cases can be estimated indirectly based on the deviation of the observed SRB from the natural level.