Master's Project Title:

Is there an association between previous preterm birth or low birth weight and maternal smoking in subsequent pregnancy?

MCH Student:

Kirsten Van Loh-Ehresmann

Date of Defense:

March 27, 2012


Background: Preterm birth and low birth weight are two of the most common causes of infant morbidity and mortality, and maternal smoking during pregnancy is a potent behavioral risk factor. Eliminating maternal smoking during pregnancy is among the highest US public health priorities and the topic of rigorous research and intervention initiatives. Yet, intertwined factors make research and finding an effective solution difficult.

Objective: The purpose of this study was to examine the smoking status in the most recent pregnancy to determine whether women with a previous PTB/LBW were more or less likely to smoke compared to women with no previous live births.

Methods: This exploratory study used weighted data from the pooled 2004-2008 Minnesota Pregnancy Risk Assessment Monitoring System survey (PRAMS) (n=7,133). Using Stata 11.1, cross sectional bivariate and multivariate models were used to test the association between smoking status and pregnancy history.

Results: Compared to women with no previous live births, women experiencing a previous PTB/LBW were more likely to smoke during the most recent pregnancy (Adjusted OR=1.34). In the current pregnancy 14.2% of women with no previous live births smoked and had a PTB/LBW, compared to 15.6% of women with a previous PTB/LBW.

Conclusions: In the analysis of PRAMS data, the prevalence of maternal smoking during pregnancy is higher among those with a history of PTB/LBW, even after adjusting for potential confounding factors, suggesting history of PTB/LBW may not influence smoking in subsequent pregnancies. Ultimately, more research and intervention efforts need to focus on women at-risk for poor pregnancy outcomes.