Daily snuff use during pregnancy, gestational length and birth weight; register-based study

Area of Science:

• Obstetrics and Gynecology
• Perinatal Medicine
• Public Health

Background:

• Snuff, a smokeless tobacco product, is prevalent in Scandinavia and increasingly used by women of reproductive age.
• Persistent snuff use during pregnancy is linked to adverse pregnancy outcomes.
• Distinguishing between occasional and daily snuff use is crucial for understanding its impact.

Purpose of the Study:

• To estimate the association between the frequency of maternal snuff use and gestational length.
• To determine the impact of maternal snuff use on birth weight.
• To compare the effects of snuff use versus cigarette smoking on pregnancy outcomes.

Main Methods:

• Utilized data from Norway's Medical Birth Registry for pregnancies in 2020-2021.
• Employed quantile regression to analyze associations between snuff use and gestational length/birth weight at term.
• Adjusted for maternal age, pre-pregnancy weight, and parity, and compared outcomes based on maternal snuff and cigarette use.

Main Results:

• Daily snuff use in the last trimester was associated with a median reduction of 3.4 days in gestational length.
• A median reduction of 44g in term birth weight was observed with daily snuff use through the last trimester.
• Mothers who smoked daily had significantly shorter gestational length (2.1 days reduction) and lower birth weight (294g reduction) compared to non-smokers.

Conclusions:

• Daily snuff use throughout the last trimester of pregnancy is linked to a significant reduction in gestational length.
• Snuff use affects birth weight, though less dramatically than smoking, indicating other components in cigarettes may be more detrimental to fetal growth.
• The findings suggest that factors other than nicotine, such as toxic chemicals or reduced oxygen supply from smoking, play a larger role in inhibiting fetal growth.