Sunday, January 10, 2021

Air pollution likely led to 29% pregnancy loss in #India, #Pakistan, #Bangladesh — Lancet study


  

Study in Lancet Planetary Health also finds that pregnancy loss associated with air pollution is more common in the northern plains of India and Pakistan.

Poor air quality has been associated with a significant proportion of pregnancy loss in India, Pakistan, and Bangladesh from 2000-2016, according to a study published in Lancet Planetary Health.

The epidemiological case-control study — the first to quantify the impact of air pollution on pregnancy loss in South Asia — said that exposure among mothers to ambient particulate matter (PM 2.5) was associated with pregnancy loss, which included stillbirths and miscarriages. 

It also stated that in India, Pakistan and Bangladesh, air pollution might have contributed to as much as 29 per cent of pregnancy losses.

The annual PM 2.5 standard of India is 40 mg/m3. Worldwide, 10 of the top 20 cities with the highest PM 2.5, are in India.
The Lancet study, published this month, stated that South Asia was one of the polluted regions in the world and had the highest burden of pregnancy loss globally.
Lead author of the study, Dr Tao Xue, from Peking University in China, said, “South Asia has the highest burden of pregnancy loss globally and is one of the most PM 2.5 polluted regions in the world.”“Our findings suggest that poor air quality could be responsible for a considerable burden of pregnancy loss in the region, providing further justification for urgent action to tackle dangerous levels of pollution,” he added.
Findings of the study
The data for the study was collected from the Demographic Health Surveys from India, Pakistan, and Bangladesh during 1998–2016, for women who reported at least one pregnancy loss and one or more live births.
The researchers estimated exposure to PM 2.5 air quality during a woman’s pregnancy by studying various modelling outputs.
They created a model to examine how exposure to air quality of PM 2.5 increased women’s risk of pregnancy loss. They did this by calculating the risk for each increase in 10 micrograms per cubic metre (10 mg/m3) in PM 2.5 after taking into account maternal age, humidity, seasonal variation, and temperature.
The team then calculated the number of pregnancy losses, which might have been caused in the region from 2000-2016 due to exposure to PM 2.5. It found that a 7 per cent annual pregnancy loss was due to exposure to PM 2.5 when India’s air quality exceeded the acceptable limits for that time period.
The study also found that a woman’s risk of pregnancy loss increased by 3 per cent with each increase in 10 mg/m3, and that air pollution could have contributed to 29 per cent of the pregnancy losses.
The study included 34,197 women in the region, who had lost a pregnancy, which included 27,480 miscarriage and 6,717 stillbirths. Out of these, 77 per cent of the pregnancy losses were from India, 12 per cent from Pakistan and 11 per cent from Bangladesh. The study also stated: “During 2010-15, 178 million (25.5 per cent) of 698 million babies born globally were born in India, Pakistan, and Bangladesh combined, but 9,17,800 (35.0 per cent) of 26,20,000 stillbirths occurred in these countries.”
Limitations
The study also revealed that pregnancy loss associated with air pollution was more common in the northern plains of India and Pakistan.
The researchers, however, pointed out some limitations in their study.
They said gaps such as the under-reporting of pregnancy losses — either due to stigma or ignoring pregnancy losses that occurred during the early gestational stage — could result in an underestimation of the link between poor air quality and pregnancy loss. https://theprint.in/health/air-pollution-likely-led-to-29-pregnancy-loss-in-india-pakistan-bangladesh-lancet-study/581519/

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