The Relationship between Maternal Smoking and Infant Birth Weight: Improving Accuracy through Urine Cotinine Analysis and Effective Medical Record Strategies.

Infant birth weight significantly reduced in mothers with exposure to nicotine during pregnancy. The number of women exposed to nicotine during late pregnancy (measured in urine) was markedly higher than self-reported and national smoking percentages, suggesting an urgent need for an improvement in medical record reporting on smoking habits to better assess neonatal outcomes.