Related Experiment Video
Updated: Oct 13, 2026

Construction of Vapor Chambers Used to Expose Mice to Alcohol During the Equivalent of all Three Trimesters of Human Development
Published on: July 13, 2014
Smoking during pregnancy increases the risk of preterm births among parous women
T Kolås1, J Nakling, K A Salvesen
1Department of Obstetrics and Gynecology, Lillehammer County Hospital, Norway.
Background:
We wanted to study a possible association between smoking during pregnancy and preterm birth.
Methods:
A population based prospective study was performed among 7,236 consecutive pregnancies over seven years delivered at one birth clinic. Smoking habits were obtained at a routine ultrasound examination around 18 gestational weeks, and preterm birth was defined as delivery of a child between 24 and 37 gestational weeks. We estimated relative risk (odds ratio) between smoking, possible confounding variables and preterm birth using multiple logistic regression analysis.
Results:
Overall, 1,769 (25%) women said that they smoked every day during their pregnancy. The smoking women had an increased risk of preterm delivery compared with non-smokers (odds ratio 1.53, 95% confidence interval 1.24, 1.89). However, this association was only demonstrated among the multiparous women (odds ratio 1.88, 95% confidence interval 1.39, 2.54). The association was statistically significant after adjusting for maternal age, diabetes, cervical conization, preeclampsia, placental abruption and placenta previa in a multivariate analysis, and we observed a dose-response effect of maternal smoking on preterm birth among multiparous women.
Conclusion:
For multiparous women smoking during pregnancy increases the risk of preterm delivery, and there seems to be a dose-response effect of smoking.
Related Concept Videos
Stress Prevention and Stress Management Techniques IV
Upper Respiratory Drugs: Antitussives, Expectorants, and Mucolytics
Antitussives include codeine, dextromethorphan (Robitussin), and benzonatate (Tessalon). Codeine and dextromethorphan exert their effects centrally by suppressing the cough reflex center in the medulla. Benzonatate operates peripherally within the respiratory tract by anesthetizing...
Asthma-I: Introduction
Teratogenicity
Stimulants
Cocaine can be administered via snorting, injection, or smoking. It primarily functions by blocking the reuptake of dopamine, resulting in a euphoric high characterized by an intense sensation of happiness and...
Development of the Oral Microbiota
