Infant delivery costs related to maternal smoking: an update

Adverse maternal and infant health outcomes due to maternal smoking are well known. Previous estimates of health care costs for infants at delivery attributable to maternal smoking were $366 million, $704 per smoker, in 1996 dollars. Changes in antenatal and neonatal care, medical care inflation, and declines in the prevalence of maternal smoking call for an updated analysis.

We used Pregnancy Risk Assessment Monitoring System for 2001/2002 to estimate the association of maternal smoking to Neonatal Intensive Care Unit (NICU) admission and, in turn, the length of stay for infants admitted/not admitted. Models are then used with 2003 natality files to derive predicted expenses as is and "as if" mothers did not smoke. The difference in these predicted expenses is smoking attributable expenses (SAEs). The updated analysis incorporated Hispanic ethnicity as an additional variable, data from 27 as opposed to 13 states, and updated (2004) NICU costs per night.

In contrast to earlier work, we find no significant association of maternal smoking and NICU admission but rather, a positive effect on the length of stay of exposed infants once admitted to the NICU. SAEs were estimated at $122 million (CI = -$29m to $285m) nationally and $279 (CI = -$76 to $653) per maternal smoker in 2004 dollars.

Declines in maternal smoking prevalence between the mid-1990s and 2003 combined with a weaker relationship of maternal smoking to NICU admission offset medical care inflation such that infants' SAEs declined. Yet, these are significant in magnitude, incurred immediately and highly preventable.