NEW DELHI: Extreme temperatures in the Indo Gangetic Plains of India - either too cold or hot - coupled with hazardous pollution is linked to an increase in preterm births, a leading cause of neonatal mortality and associated with long-term physical, neurodevelopmental and socioeconomic effects, a first-of-its-kind study said.
Noting that despite recent improvements, India continues to record preterm birth - when babies are born alive before 37 weeks of pregnancy are completed - at a considerable frequency, especially in the Indo-Gangetic Plains (IGP), in states like Uttar Pradesh, Bihar and West Bengal, which exhibit high climate vulnerability.
Published in the journal BMC Pregnancy and Childbirth, the study warned that in the future, the changing climate is likely to lead to more and more extreme heat in summers and more extreme pollution in winters in densely populated basins like IGP, which threatens to largely reverse the recent progress made in the field of maternal and child health by India.
In 2020, an estimated 13.4 million babies were born preterm globally. With the prevalence of 9.9% preterm births among all births, India alone accounted for 3.02 million preterm births - over 20% of the global total.
What is worrying is that the vulnerability to extreme temperatures is more pronounced among low-income populations, the study said.
India, the sixth-most-affected country globally by extreme weather, has nine states among the top 50 most climate-vulnerable regions.
Speaking to TNIE, Dr Ambarish Dutta, the senior author of the study, and Professor, Epidemiology, Indian Institute of Public Health, Bhubaneswar, Public Health Foundation of India (PHFI), said, “our current study results show that pregnancy outcomes of women living in middle and lower Indo-Gangetic plains of India, comprising UP, Bihar and Gangetic West Bengal, are significantly determined by their exposure to atmospheric temperature during their pregnancy.”
Dr Dutta said their study showed that among pregnant women who were exposed to the highest 20% average temperature during their entire pregnancy as compared to the middle 20% carried an additional risk of 126% to deliver pre-term babies, an outcome which is considered a substantial intergenerational handicap for newborn.
“But more strikingly, women who were exposed to the lowest 20% average temperature during their entire pregnancy also had a very high elevated risk of preterm birth, even though in these areas winter is not at all as harsh as in many other parts of the world,” he added.
However, he added that the likely underlying reason for this phenomenon is that colder weather is synonymous with extreme pollution in this unique climatic basin of the Indo-Gangetic Plains.
“These findings from the most densely populated and most agriculturally productive region of India have considerable potential to unlock policy actions, be it in reducing environmental pollutants during winter in IGP or prioritising special monitoring of pregnant mothers whose pregnancy duration coincides largely with the months with extreme weather,” the study said.
For the study, the researchers, including experts from Mamta Health Institute for Mother and Child, an NGO, used data from the National Family Health Survey (NFHS)-5. The study included 36,851 women from Uttar Pradesh, Bihar, and West Bengal because they are highly vulnerable to climate change and have high poverty rates, making it difficult for the dense population to adapt to environmental hazards.
Dr Dutta said protecting pregnant women from the physiological strain of extreme temperatures requires a unified effort both at the individual and government levels.
“At the individual level, family members should take on all physically demanding tasks to shield expectant mothers from overexertion and environmental stress, and also have access to clean drinking water. State-led initiatives, such as public awareness campaigns, early weather warnings, and guaranteed access to water for hydration and hygiene, must reinforce this personal care,” he said.
He added that further by repurposing health centres as dedicated climate relief stations, the government can provide the essential infrastructure needed to mitigate the health risks posed by a fluctuating global climate.
The serious consequences of preterm birth include cognitive and developmental delays, impaired motor skills, long-term neurological and behavioural problems and increased propensity for developing non-communicable diseases during adulthood, leading to considerable disease and economic burden at the population level.
The researchers, which included Dr Aisurya Samal, Jagyenswar Rath and Dr Jyoti Ghosal from PHFI, selected the Indo-Gangetic Plain for their study because it experiences a subtropical climate with hot summers and short, yet distinctly cool, winters, and, most importantly, recurrent episodes of hazardous air quality.