Silent Harm: How Ambient Air Pollution Threatens Prenatal and Neonatal Health. A Systematic Review.

The included studies were mostly observational, so they show associations, not proof that air pollution caused the outcomes. Exposure measurement varied across studies, and actual inhaled dose may be misclassified. Other factors such as socioeconomic status and location may not have been fully controlled. The review combined many pollutants, populations, and time periods, so the same risk may not apply everywhere. One included cross-sectional study had a poorer quality score, and the review kept it because its findings matched higher-quality studies. No intervention was tested, so the paper cannot say what reduces risk.

Do not read these links as proof that reducing air pollution will prevent miscarriage, preeclampsia, preterm birth, or newborn respiratory distress. The review included observational studies, not interventions, and the paper reports associations rather than cause and effect.