Trimester-Specific and Dose-Dependent Associations Between Maternal Smoking and Neonatal Birth Weight: A Population-Based Analysis of the CDC WONDER Natality Database (2016–2024)
Bengü Mutlu Sütcüoğlu1, Cemre Karçaaltıncaba2, Deniz Karçaaltıncaba31Department of Obstetrics and Gynaecology, Ankara Atatürk Sanatoryum Research and Training Hospital, Ankara, Türkiye, 2Department of Obstetrics and Gynaecology, Ankara Etlik City Hospital, Ankara, Türkiye, 3Department of Perinatology, Faculty of Medicine, Gazi University, Ankara, Türkiye
Objectives: Maternal smoking during pregnancy impairs fetal growth, yet the relative contribution of trimester-specific exposure and cessation timing remains unclear. Quantitative trimester-based analyses that integrate cigarette dose and neonatal outcomes are limited. Methods: This retrospective, population-based study used data from the CDC WONDER Natality database (United States, 2016–2024). Women who reported smoking at the beginning of pregnancy and had complete trimester-specific data were included. Smoking exposure was analyzed both categorically and quantitatively (cigarettes per day). The primary outcome was neonatal birth weight (grams); a secondary analysis assessed small-for-gestational-age (SGA) among term deliveries. Multivariable linear regression was adjusted for maternal age, pre-pregnancy BMI, gestational weight gain, interpregnancy interval, and pregnancy-related morbidities. ROC analysis identified discriminatory thresholds. Results: Among 4,931 pregnancies, second-trimester smoking showed the strongest independent negative association with birth weight (B=?1.246 g per cigarette; p<0.001), followed by first-trimester smoking (B=?0.957 g; p<0.001). Thirdtrimester smoking had minimal clinical impact. Second-trimester cessation was associated with higher birth weight (p<0.001), whereas third-trimester cessation showed no benefit. Among term births, only first-trimester smoking was associated with SGA (p=0.022). A threshold of 15 cigarettes per day predicted SGA with a sensitivity of 71% and a specificity of 75%. Conclusion: Smoking timing critically determines fetal growth impact, underscoring the importance of very early cessation. Keywords: Birth weight, Maternal smoking, Smoking cessation
Cite This Article
Mutlu Sütcüoğlu B, Karçaaltıncaba C, Karçaaltıncaba D. Trimester-Specific and Dose-Dependent Associations Between Maternal Smoking and Neonatal Birth Weight: A Population-Based Analysis of the CDC WONDER Natality Database (2016–2024). EJMI. 2026; 10(1): 65-72
Corresponding Author: Bengü Mutlu Sütcüoğlu