Researchers have found that an estimated 349,681 pregnancy losses in India, Bangladesh and Pakistan are associated with poor air quality each year.
But the study is likely to be the first of its kind to quantify the effects of environmental pollution on pregnancy loss in South Asia – one of the most polluted regions on earth – and according to the authors, their findings are important for improving public and maternal birth. health, especially in low-income countries.
“South Asia has the largest burden of pregnancy loss worldwide and is one of the most PM2.5 polluted regions in the world. Our findings suggest that poor air quality may be responsible for a significant burden of pregnancy loss in the region, which further justifies calls for urgent action to address dangerous levels of pollution, “said Dr. Tao Xue, lead author of the study, assistant professor at the University of Beijing, China, said.
PM2.5 is a small contaminant of particles that can move deep into the lungs when inhaled and enter the bloodstream. The particles, which consist of dust, dirt, soot or smoke, come from construction sites, unpaved roads, lands, smoke or fire, and can contain various chemicals. But most particles are a mixture of pollutants from the emissions of power stations, industries and vehicles.
Researchers have focused on these small pollutant particles. They found that between 7 and 7% of pregnancy losses in South Asia between 2000 and 2016 were due to mothers exposed to air pollution that exceeded India’s current air quality standard of 40 micrograms per cubic meter of air.
Expectant mothers from rural areas or those who were older were at greater risk than young mothers from urban areas, the study found. Loss of pregnancy associated with air pollution is more prevalent in the Northern Plains region of India and Pakistan.
To reach their findings, researchers examined data from household surveys on health from 1998 to 2016 and exposure to pollution during pregnancy using satellites. Subsequently, they created a model that investigates how exposure to pollution increases a woman’s risk of pregnancy loss, taking into account maternal age, temperature and humidity, seasonal variation, and long-term trends in pregnancy loss.
The study included 34,197 women who lost a pregnancy, including 27,480 miscarriages and 6,717 stillbirths. Of the pregnancy losses, 77% were from India, 12% from Pakistan and 11% from Bangladesh.
According to the authors, poorer air quality can increase the burden of pregnancy loss in low- and middle-income countries, so improving pollution levels can reduce miscarriages and stillbirths and lead to improvements in gender equality.
“We know that the loss of pregnancy can have mental, physical and economic consequences for women, including an increased risk of postnatal depression, infant mortality during subsequent pregnancies, and the costs associated with pregnancy, such as loss of labor,” he said. co-author Dr. Tianjia Guan, of the Chinese Academy of Medical Sciences and the Beijing Union Medical College.
The study warns that more research is needed to determine causality between contamination and loss of pregnancy, as the data from the survey are subject to memory bias. The researchers also could not distinguish between natural pregnancy loss and abortions. They also note that natural loss of pregnancy has been reported due to stigma or the fact that many early miscarriages have been ignored.