New Delhi: Delhi’s toxic air is no longer just choking lungs and damaging hearts — it is now silently entering the womb and harming unborn children, according to a landmark study conducted by the All India Institute of Medical Sciences (AIIMS), Delhi.
In a shocking revelation, researchers have found that fine particulate matter, especially PM2.5, can breach the placental barrier of pregnant women and directly affect the developing embryo, restricting foetal growth and increasing the risk of low birth weight, premature birth and pregnancy complications.
The ICMR-funded study, published in EMBO Molecular Medicine in June 2026, is being described as one of the most comprehensive Indian studies explaining exactly how air pollution attacks the unborn child at a molecular level.
The AIIMS team discovered that toxic particles from polluted urban air trigger inflammation inside the placenta and suppress IGFBP3 — a critical protein responsible for maintaining placental balance and healthy embryo growth. Once this protein is disrupted, the placenta fails to form blood vessels properly and cannot transfer nutrients efficiently to the foetus.
Researchers warned that the consequences go far beyond birth. Babies exposed to pollution inside the womb may face developmental delays, poor motor coordination, anxiety-related disorders and long-term health complications extending into childhood.
The study analysed 994 deliveries from heavily polluted Delhi and comparatively cleaner Deoghar in Jharkhand. The findings showed a clear link between high PM2.5 exposure in Delhi and increased cases of low birth weight and preeclampsia among pregnant women.
Deoghar, where pollution levels were significantly lower, reported fewer adverse pregnancy outcomes, strengthening the evidence that urban air pollution is directly affecting maternal and foetal health.
In laboratory and animal studies, scientists mapped the entire biological pathway showing how PM2.5 and PM10 particles penetrate the placenta, trigger oxidative stress and inflammation, and gradually interfere with foetal development.
Dr. Subhradip Karmakar
The findings also support broader national data. A geostatistical analysis using NFHS-5 and satellite pollution mapping had earlier shown that every 10 microgram per cubic metre rise in PM2.5 exposure during pregnancy increases the risk of low birth weight by 5 per cent and preterm birth by 12 per cent. Northern India, particularly Delhi and adjoining regions, showed the strongest association.
According to Dr. Subhradip Karmakar, Professor in the Department of Biochemistry at AIIMS Delhi, previous research had examined isolated aspects of pollution exposure, but this study mapped the “entire pathway” of damage caused by polluted air during pregnancy.
“While this has been studied before, it has been done in a piecemeal way. We showed the entire pathway,” he said.
Dr. G. C. Khilnani
The study has intensified concerns among doctors and public health experts, who say pregnant women living in highly polluted cities are among the most vulnerable populations in India.
According to Dr. G. C. Khilnani, Chairman of PSRI, expectant mothers are advised to minimise exposure by using indoor air purifiers, wearing N95 masks during severe pollution days, avoiding outdoor activities during peak pollution hours, and ensuring regular prenatal monitoring.
(Cover Representative Image: pmsma.mohfw.gov.in)
