Our analyses find that selective female abortion in India has grown in the last two decades and accounts for most of the large and growing imbalance between the number of girls to boys at ages 0–6 years. Sex ratios for births that followed a firstborn girl fell sharply from 1990 to 2005, even though sex ratios for all births (regardless of birth order) did not. Increases in selective female abortion are likely due to persistent son preference11
combined with decreases in fertility: third or higher order births as a proportion of all births fell from 49% in 1990 to 38% in 2005 in our study (and to 32% in 200810
; web table 2
). Son preference varies little by education or income11
, but selective female abortion is more common among educated or richer households, presumably because they can afford ultrasound and abortion services more readily than uneducated or poorer households. Recent increases in literacy1
and Indian per capita income20
might have thus contributed to increased selective female abortion.
While large in absolute terms, selective abortion of female foetuses still accounts for only a minority of all annual female pregnancies (about 2–4%, or roughly 0.3–0.6 million, of the expected number of 13.3–13.7 million pregnancies in 2010 carrying a girl). Women with a first or second order girl are most clearly at risk of aborting subsequent female foetuses. We did not yet see any clear evidence of selective abortion of firstborn female foetuses. This is partly because India does not enforce a one-child policy, which led to the selective abortion of firstborn female foetuses in China.21
However, selective abortions of first-order females might increase if fertility drops further, particularly in urban areas.
Although our birth data were only until 2005, a district-based household survey from 2005–2007 found similar conditional sex ratios for births following a firstborn female.22
Thus, selective abortion remains common among the most recent cohorts of children captured in the 2011 census. shows a remarkable shift in the population living in states where the child sex ratios at ages 0–6 are below 915 girls per 1000 boys; rising from 10% in 1991, to 27% in 2001 and 56% in 2011. Thus, we conclude that most of India's population now lives in states where selective female abortion is commonly practiced.
Distribution of the total population living in states with varying child sex ratios (girls per 1000 boys at ages 0–6 years), 1991, 2001 and 2011, in India
The Indian government implemented a Pre-Natal Diagnostic Techniques (PNDT) Act in 1996 to prevent the misuse of techniques for the purpose of prenatal sex determination leading to selective female abortion.23
It is unlikely that this Act has been effective nationally as few health providers have been charged or convicted.24
This is not surprising given that most primary care occurs with unregulated private providers.25
More than twice the number of districts showed declines in the child sex ratio between 2001 and 2011 censuses compared to the number of districts showing no change or increases in child sex ratio. However, the 170% rate of increase in selective female abortions from the 2000s to the 2010s is slower than the 260% rate of increase from the 1990s to the 2000s. Indeed, the 2011 census noted the child sex ratios at ages 0–6 years had increased somewhat in the states of Haryana and Punjab, and had stabilised in Gujarat1
, as seen in district-level analyses () of the same data. It might be that the PNDT Act, plus the recent public attention to selective female abortion, has reduced the practice in some settings. Our results are consistent with reports that ultrasound and abortions are far more common in second and third order births than in firstborns.26, 27
However, our method based on conditional birth histories is unlikely to be biased by misreporting of ultrasound use.26
Our study has some limitations. First, the sex ratios in the NFHS are based on birth histories, which vary considerably from year to year. This is in part due to random variation from only a few hundred or thousand births, as well as possible systematic under-enumeration of girls and recall biases for birth histories in retrospective surveys.11, 28
However, our key analysis was of trends, where the yearly variation is less important. We therefore relied on actual enumerated children in the censuses to calculate absolute totals of missing girls rather than the NFHS birth histories. The census omission rates are small, and do not vary greatly by gender,16
which might have otherwise resulted in spurious sex ratios. Second, our annual estimates of selective female abortions relying on the census are, by necessity, quite crude. The current study estimates are notably more conservative than those estimated from birth histories in the Sample Registration System (SRS; a large, continuous, nationally representative demographic survey of over 1 million homes).10
Specifically, SRS-based estimates of annual selective female abortions were 0.59–0.74 million in 19978
and 0.48–0.67 million during 2001–20039
(web table 4
). However, the 4–12 million estimate of selective female abortions from 1980–2010 is consistent with our earlier (cruder) estimate of about 10 million selective female abortions from 1985–20058
, as well as Kulkarni's estimate of 8 to 18 million selective female abortions from 1981–2006.29
Third, the exact contribution of selective female abortion to the measured gender imbalance at ages 0–6 years in the censuses also depends on child mortality rates. However, only in recent years did slightly more girls die compared to boys2
, and we adjusted our estimates for higher girl mortality had more girls been born. Fourth, the sex ratio range at birth of 950 to 975 girls per 1000 boys is based on observations in Europe and North America, and might not apply to Asian populations for unknown biological reasons.30
However, such sex ratios at birth were documented in some Indian states as recently as 1991.1
While unmeasured factors might reduce or increase overall sex ratios at birth, they are unlikely to be conditional on birth order.5
Finally, we found in this study, as in earlier reports8,9
and in unpublished data on birth histories in Indian diasporas (data not shown), a small and currently inexplicable excess of third girls following the birth of two earlier boys.
In sum, selective abortion of female foetuses, usually following a firstborn girl, has increased in India over the last few decades, and has contributed to a widening imbalance in the child sex ratio. Reliable monitoring and reporting of sex ratios by birth order in each of India's districts is a reasonable part of any efforts to curb the remarkable growth of selective female abortions.