Widespread elective abortion of female fetuses – particularly among families with girl children already – is the likeliest reason for a marked gender imbalance among Indian children in recent decades, researchers have learned.
Currently, the sex ratio in children aged 6 years and younger in India is 915 girls to 1,000 boys, the lowest ever recorded in India. The normal expected ratio would be between 950 and 975 girls per 1,000 boys.
The new study, published online May 24 in the Lancet, was the first to identify as a likely culprit the selective abortion of second-order girls, using data from national birth cohorts and censuses (Lancet 2011 May 24 [doi:10.1016/S0140- 6736(11)60649-1]).
For their research, Dr. Prabhat Jha of the Dalla Lana School of Public Health at the University of Toronto, along with his colleagues in India, analyzed sex ratios by birth order in surveys of 250,000 births in 1990-2005. They estimated totals of selective abortion of girls by assessing records of children through 6 years of age in the 1991, 2001, and 2011 censuses.
In 1990, the researchers found, there were 906 girls born for every 1,000 boys in India among all second-order births; in 2005, female second-order births had dropped to 836 for every 1,000 males, representing an annual decline of 0.52%. While sex ratios for births after a firstborn girl fell sharply in this period, sex ratios for births after a firstborn boy did not change – suggesting that families were aborting to ensure themselves at least one son.
The trend was seen in a majority of states in India and shown to be most pronounced among both higher-income and more-educated families, suggesting that India’s recent increases in literacy and per-person income might be contributing to increased selective abortion of second-order girls.
Selective abortion has been prohibited by Indian national law since 1996, Dr. Jha and his colleagues wrote in their analysis, yet few practitioners have been convicted for it, and it appears to be practiced in all states. While preference for sons is widespread among all social classes in India, wealthier people have more access to ultrasound and abortion services, including those offered illegally for sex selection.
Dr. Jha and his colleagues calculated the number of selective abortions by adjusting for excess mortality rates in girls, with each 1% decline in child sex ratio between birth and age 6 years representing between 1.2 and 3.6 million more selective abortions of girls. They estimated that selective abortions of girls rose from fewer than 2 million in the 1980s, to between 1.2 and 4.1 million in the 1990s, to between 3.1 and 6 million in 2000-2010.
The estimates of the actual numbers of selective abortions, Dr. Jha and his colleagues wrote, "are, by necessity, crude." They also noted as a potential weakness of their study that "the exact contribution of selective abortion of girls to the measured sex imbalance at ages 0-6 years in the censuses" was dependent on child mortality, which has tended historically in India to be heavier among girls, presumably because of resource allocation favoring boys. Also, not all births in India are recorded, and the family surveys used by Dr. Jha and his colleagues rely on a mother’s recall of her birth history.
Although "unmeasured biological factors, such as infections, might reduce or increase overall sex ratios at birth, they are unlikely to be conditional on birth order," Dr. Jha and his colleagues wrote.
Although Dr. Jha and his colleagues noted that the rate of increase in selective abortions of girls seems to have slowed, from 260% between 1991 and 2001 to 170% in the last decade. Still, they wrote in their analysis, "selective abortions of first-order girls might increase if fertility drops further, particularly in urban areas."
In an editorial accompanying Dr. Jha and his colleagues’ findings, Dr. S.V. Subramanian, Ph.D., of the Harvard University School of Public Health, Boston, and Daniel J. Corsi. Ph.D., of McMaster University, Hamilton, Ont., wrote that they found the decline in sex ratios "counterintuitive, in view of India’s progress in recent decades in improving the levels of female literacy and increases in income per person" (Lancet 2011 May 24 [doi:10.1016/S0140-6736(11)60709-5]).
With the sex ratio of children through 6 years in India at 915 girls for 1000 boys— "the lowest ratio recorded since data became available in 1961," Dr. Subramanian and Dr. Corsi wrote, the prospects for normalization appeared "grim."
The findings, they wrote, show that socioeconomic development has not offset the "dominance of the son-preference norm" in India. "The overall problem of sex imbalance seems to arise throughout India, including in Kerala, which has often been characterized as a model state for social development and gender equality."