Air Pollution Impact on Pregnancy and Early Childhood Development (APiPED) in India: Protocol for a Cohort Study

The impact of air pollution on early childhood development in low-pollution settings is well known. However, comprehensive evidence from high-pollution environments such as the Delhi National Capital Region in India remains limited.

This maternal-child cohort study aims to investigate the impact of air pollution on pregnancy outcomes and early childhood development, providing critical insights to inform targeted interventions and public health policy.

This longitudinal maternal-child cohort study will enroll 2500 pregnant women from rural and urban Delhi National Capital Region and follow their children up to 2 years of age. Maternal data on pregnancy complications, delivery mode, parity, and gestational weight gain will be collected from clinical records and structured questionnaires, while newborn outcomes (gestational age, birth weight, anthropometry, and congenital anomalies) will be assessed from birth records and clinical examination. Early childhood development will be evaluated through standardized anthropometry and the Developmental Assessment Scale for Indian Infants. For a 10% subsample, trimester-specific and postnatal indoor and outdoor air pollution exposure (particulate matter with a diameter of less than 2.5 micrometers and particulate matter with a diameter of less than 10 micrometers) will be monitored using portable air quality monitors, along with household surveys and time-activity diaries. Maternal and infant blood samples will be analyzed for inflammatory, oxidative stress, and cardiovascular biomarkers. Exposure estimates will be integrated into personal exposure models, and associations with health outcomes will be examined using multivariable regression and longitudinal mixed-effects models.

As of July 2025, 45% of the planned sample size have been recruited, with baseline data collection completed, and 10% undergoing exposure assessment and sample collection.

This study will provide a comprehensive evaluation of the effects of air pollution on maternal health, pregnancy outcomes, and early childhood development in urban and rural settings in India. This will generate context-specific evidence to support maternal and child health policies, air pollution mitigation strategies, and personal protection measures for pregnant women and infants in polluted environments.

DERR1-10.2196/72683.