Snus users had high levels of nicotine, cotinine and 3‐hydroxycotinine in their breastmilk, and the clearance was slower than in smoking mothers

Abstract

Aim Using snus, an oral moist tobacco, has increased among pregnant women in Sweden, the only European Union country where sales are legal. This study evaluated whether snus generated similar concentrations of nicotine and its metabolites in breastmilk to cigarette smoking. Methods We analysed 49 breastmilk samples from 33 nursing mother – 13 snus users, six cigarette smokers and 14 controls – for concentrations of nicotine, cotinine and 3‐hydroxycotinine. The mothers were recruited at antenatal clinics in Sweden from 2007 to 2012. Results The median nicotine concentration in breastmilk of the snus users was 38.7 ng/mL (0–137) versus 24.0 ng/mL (0–56) in smokers, with median cotinine levels of 327.6 ng/mL (37–958) versus 164.4 ng/mL and median 3‐hydroxycotinine levels of 202.7 ng/mL (28–452) versus 112.4 (0–231), respectively. Nicotine was still detected in the breastmilk of eight of the 13 snus users after abstaining from tobacco for a median duration of 11 hours (0.6–12.5), while the breastmilk of the smokers was nicotine‐free after four hours’ abstinence. Conclusion Snus users had high levels of nicotine and metabolites in their breastmilk and nicotine was found even after 12.5 hours of abstinence.

Highlights in this issue

“…Nordenstam et al. report that snus users in their study had high levels of nicotine and metabolites in their breastmilk and nicotine was even found after 12.5 hours of abstinence. Readers may also be interested in the mini‐review by Kreyberg et al.…”

An update on prevalence and risk of snus and nicotine replacement therapy during pregnancy and breastfeeding

“…We found no study assessing potential effects on the infant by snus and NRT exposure through breast milk. A recent study reported however that snus users had higher levels of nicotine in their breast milk compared with smokers . Breastfeeding is important for infant health, yet potential risk of exposure to nicotine from breast milk remains unknown.…”

“…Nicotine easily passes the placenta and can be detected in human foetal circulation and amniotic fluid at concentrations higher than those in the maternal plasma . Further, compared with smoking, snus used by breastfeeding women has been shown to give higher levels and prolonged presence of nicotine in breast milk, with at least 12.5 hours in snus users and four hours in smokers following abstinence .…”

Maternal use of nicotine products and breastfeeding 3 months postpartum

“…[1][2][3] Moreover, breastfed infants exposed to smoking or snus by their nursing mothers are exposed to high levels of nicotine through the breast milk. 4,5 Nicotine may remain in the breast milk for 12.5 hours after the last snus dose and 4 hours after the last cigarette. 5 Smoking during breastfeeding has been shown to reduce the health promoting properties of breast milk including lower fat concentration, reduced milk production possibly through reduced levels of prolactin, shorter breastfeeding periods 6 and may affect the taste of the breast milk.…”

“…4,5 Nicotine may remain in the breast milk for 12.5 hours after the last snus dose and 4 hours after the last cigarette. 5 Smoking during breastfeeding has been shown to reduce the health promoting properties of breast milk including lower fat concentration, reduced milk production possibly through reduced levels of prolactin, shorter breastfeeding periods 6 and may affect the taste of the breast milk. Moreover, an increased risk for several conditions has been observed in the smoke-exposed infant, including colic, sleep disruption, 7 allergies, respiratory disorders, 6,8 neurobehavioural disorders, 7 sudden infant death syndrome, 6,7 altered heart rate variability, 9 and overweight and obesity later in life.…”