Despite overall progress in bringing down low birthweight numbers across India over the past 30 years, rates remain stubbornly high in certain states, with Uttar Pradesh, Bihar, Maharashtra, and West Bengal, accounting for almost half of all such births, finds research published in the open access journal BMJ Global Health.
Low birthweight is important, because it often signals underlying maternal health issues and poor nutrition as well as the child's future cognitive development and susceptibility to chronic conditions in later life, note the researchers.
While some states have made rapid progress in bringing down the prevalence of low birthweight, others have found it more difficult, they add.
To try and build an accurate picture of progress across the country over the past 30 years, the researchers drew on data for women and girls aged 13 or 15 to 49 in five waves of the nationally representative National Family Health Survey spanning the period 1992–3 to 2019–21. Low birthweight was defined as less than 2500 g.
Of the total 626,087 live births during the study period, 165,073 (26.5%) newborns weren't weighed and the information was missing for 20,814 (just over 3%); and 440,200 (just over 70%) were weighed. The size of 614,428 (98%) was subjectively assessed by the mother.
The number of recorded births rose from 48,959 in 1993 to 232,920 in 2021. And the proportion of these babies who were weighed increased over time, resulting in 7,992 being included in the analysis in 1993 (16%) to 209,266 in 2021 (90%).
The state-level average prevalence of low birthweight fell across the 5 surveys from 25% in 1993 and 1999; to 20% in 2006; 17% in 2016; and 16% in 2021. And the overall prevalence of low birthweight across India fell by 8 percentage points from 26% in 1993 to 18% in 2021.
The greatest prevalence of low birthweight in 1993 was observed in Rajasthan (48%) and Chhattisgarh (42%) while the lowest was observed in Mizoram (6%) and Nagaland (11%).
In 2021, the greatest prevalence was observed in Punjab (22%) and the union territory of Delhi (22%) while the lowest prevalence was observed in Mizoram (4%), Nagaland (5%), and Manipur (7%).
The 2019–21 survey suggests that there were 4.2 million low birthweight babies in a single year in India. Just four states—Uttar Pradesh (858,000), Bihar (430,000), Maharashtra (399,000, and West Bengal (318,000)—accounted for almost half (47%) of all these births.
The figures suggest a degree of convergence, where states with greater prevalence in 1992–93 experienced faster falls.
The 2021 survey also indicated that in a single year 2.5 million children were born smaller than average size, as assessed by their mothers.
The largest number were born in the same four states as those with a high prevalence of low birthweight: Uttar Pradesh (462,000); Bihar (318,000); Maharashtra (261,000); and West Bengal (208,000), accounting for 50% of such births.
For both low birthweight and smaller than average size babies, the 2021 survey showed that these children were considerably more likely to be born to women with little or no formal education and from the poorest households.
"Low birth weight is likely to be more prevalent among non-weighed children since weighing correlates strongly with healthcare infrastructure and being born in a health facility. Also, low socioeconomic status is linked to both lack of access to healthcare and low birth weight," explain the researchers.
"The insights from data spanning nearly three decades shed light on both promising progress and enduring challenges. Our results point to a general decline in the prevalence of low birth weight and convergence between states over time," they suggest.
"However, the levels and specific numbers should be interpreted with caution due to data quality issues, particularly low levels of recorded birthweight in the older surveys," they caution.
They conclude: "Despite the overall progress, the persistence of high prevalence of low birth weight in certain states highlights the need for ongoing efforts to address maternal and neonatal health disparities. Despite improvements, data collection at healthcare facilities must also be further enhanced, to provide quality data for decision making across India."
