Maternal smoking ups IBS risk in offspring, but lactation appears protective

Individuals exposed to maternal smoking during infancy show an increased risk of incident irritable bowel syndrome (IBS), while those exposed to lactation display a reduced risk, reveals a study.

A total of 290,962 participants free of IBS at baseline and with available data on maternal smoking and lactation were included in this study. Those exposed to maternal smoking or to lactation during infancy were classified as exposure groups. Maternal smoking was characterized by regular cigarette smoking during the perinatal period, while lactation referred to any breastfeeding during the infant period.

The researchers estimated the associated risk using Cox proportional hazards model. Incident IBS served as the primary outcome.

Of the participants, 81,186 (27.90 percent) had exposure to maternal smoking, and 211,954 (72.85 percent) had exposure to lactation as infants. Some 6,222 incident IBS cases were identified over a median follow-up of 14.6 years.

After adjustments, participants with exposure to maternal smoking during infancy were at increased risk of incident IBS by 16 percent compared with those without maternal smoking (hazard ratio [HR], 1.16, 95 percent confidence interval [CI], 1.09‒1.22), whereas those exposed to lactation showed a 9-percent lower risk of IBS than unexposed individuals (HR, 0.91, 95 percent CI, 0.86‒0.97).

Notably, participants exposed to both maternal smoking and no lactation were at even greater risk of developing IBS than those with lactation exposure but no maternal smoking (HR, 1.23, 95 percent CI, 1.14‒1.34). Moreover, individuals with both maternal smoking and previous/current smoking had a significantly higher IBS risk (HR, 1.30, 95 percent CI, 1.21‒1.41).

“These findings underscore the potential impact of early-life exposures on gastrointestinal health,” the researchers said.