RESUMO
BACKGROUND: A declining sex ratio at birth has been documented during censuses in India. The decline is especially more in the northern states of Haryana and Punjab. We attempted to assess the role of society (preference for a male child, awareness and acceptability of the practice of sex determination), technology (availability and affordability) and government regulation in the adverse ratio for girls in the Ballabgarh block of Haryana in northern India. METHODS: The population (about 80 000) in the Ballabgarh block has been under constant demographic surveillance for the past 30 years and the data are stored electronically. This was used to determine the sex ratio at birth in the area since 1990. The data on availability of ultrasound machines was collected from the district authorities, as registration of these machines was made mandatory under the Prenatal Diagnostic Techniques Act, 1994. We interviewed 160 mothers and grandmothers to determine the awareness and acceptability of sex determination methods and practices. RESULTS: The demographic data for the past 10 years showed a declining sex ratio-from 881 in 1990-91 to 833 in 2000-01. The data support the view that in the initial part of this period, ultrasound was used for sex determination of all-order births but subsequently was used more in higher-order births. Our interviews with the mothers and grandmothers of the area showed that the practice of sex determination is prevalent and the attitude of the society is ambivalent. The increased availability of ultrasound machines in the area in the past 10 years corresponded to the decline in sex ratio. When the government made the practice illegal, the sex ratio improved only to fall again as the law was not implemented. Later years saw a more stringent implementation of the law and the sex ratio improved again. CONCLUSION: There is a 'demand' for sex determination technology and, therefore, this would continue to be 'supplied'. At most the 'supply' can be regulated. Social engineering efforts need to be targeted at reducing the demand if the sex ratio is to be improved.