Daily Snuff Use During Pregnancy Linked to Shorter Gestational Length, Study Shows

Snuff usage continues to be on the rise among Scandinavian women of childbearing age. Some earlier studies have reported adverse pregnancy outcomes associated with smokeless tobacco use, but snuff utilization in relation to gestational length and birth weight has been somewhat underreported. The current study attempted to estimate the association between daily and occasional snuff use during pregnancy and its impact on gestational age and birth weight. These findings were compared to the findings obtained from cigarette-smoking mothers in an attempt to shed light on whether it was nicotine alone or harmful substances in cigarette smoke that contributed to adverse pregnancy outcomes.

An analysis was done on data arising from pregnancies delivered between 2020 and 2021 in Norway's west and central regions. The study involved 18,042 nonsmoking women, who had snuff use every day before pregnancy, with 4.6% of these women continuing snuff use during pregnancy. Among this population, 1.2% continued as regular snuff users during the last trimester of pregnancy. The relation of snuff use to gestational length and birth weight at term (39–41 weeks) was examined with application of quantile regression models that controlled for many maternal factors including age, prepregnancy weight, and parity. Outcome was compared among women who never used snuff, those who quit during pregnancy, and those who used snuff sometimes or daily.

The study identified several key findings about snuff use in pregnancy and gestational length and birth weight:

• Daily use in the last trimester of pregnancy: Women who used snuff daily during the last trimester of pregnancy had an infant with a median gestational length that was 3.4 days less than that for infants whose mothers never used snuff (95% CI, -5.0 to -1.7 days).

• Weight at birth reduction: The median term weight at birth was reduced by 44 grams with a 95% CI: -134 to 46 grams from day-to-day snuff use. This reduction was significant, even though the effect was not as potent as that of cigarette smoking.

• Use of cigar or pipe snuff only on an as-needed basis: The associations were much weaker among women who used snuff only on an as-needed basis or stopped snuff use during pregnancy.

• Comparison with smoking: Mothers who smoked every day during the last trimester had more pronounced effects, with a decrease of 2.1 days in the median gestational length (95% CI: -2.7 to -1.4) and a decrease of 294 grams in the median term birth weight as compared to non-smokers (95% CI: -325 to -262).

• These results indicate that, although snuff use actually does have adverse effects on fetal development, the level of decrement is not as extreme as those from cigarette smoking.

In conclusion, this study provides key evidence that snuff taken daily during pregnancy, especially in the last trimester of pregnancy, causes a decrease in gestational length by more than three days. The reduction on birth weight, though present, was lesser than the reductions noted in the cigarette smokers. These findings suggest that although nicotine is a causative factor in poor pregnancy outcomes, it is unlikely that these toxic agents in cigarettes have a contribution of such magnitude to such an effect on fetal growth. Women of childbearing age must be made aware of the potential risk to pregnancy outcomes, and health care providers must educate the women about the danger of using any tobacco product during pregnancy.

Reference:

Lie, R. T., Magnus, M. C., Gjessing, H. K., Wilcox, A. J., & Håberg, S. E. (2024). Daily snuff use during pregnancy, gestational length and birth weight; register-based study. BMC Pregnancy and Childbirth, 24(1), 1–9. https://doi.org/10.1186/s12884-024-06863-8