Women who smoke while pregnant are at a higher risk of having daughters who become obese and/or develop gestational diabetes, according to a new study published in Diabetologia.
The fact that smoking is harmful during pregnancy has long been known, however, studies that examined possible adverse effects that last until adulthood are scarce and outcomes have been inconsistent.
A study led by the University College London (UCL) in the UK suggested that children born to women who smoke during pregnancy are at a higher risk for birth defects. These defects could include clubfoot, facial disorders, or deformed limbs.
Therefore, the authors used data from the Swedish Medical Birth Register to analyze the link between a woman smoking during pregnancy and the risk of her daughter then developing obesity and gestational diabetes.
Data was collected from the Register for 80 women who were born in 1982 (the year smoking data was first documented), or later and who had given birth to at least one child.
The data on pregnant women’s smoking behavior in the register were grouped into three categories:
- moderate smokers (1-9 cigarettes/day)
- heavy smokers (>9 cigarettes/day)
Of the daughters who were studied, 7,300 became obese and 291 developed gestational diabetes when they were pregnant later in life. The gestational diabetes risk rose by 62% among the daughters who were moderately exposed to smoking while in the womb and 52% among those who were heavily exposed.
Those daughters who were moderately exposed to smoking were 36% more likely to be obese, and of those heavily exposed 58% were more likely to be obese. These links were seen even after the authors adjusted for mode of delivery, gestational age, birth weight, age, parity, and BMI.
Findings showed that possible mechanisms behind the links may be changes in the regulation of appetite and fulling full – which has previously been seen in animal studies.
Other negative outcomes of prenatal nicotine exposure involve a greater rate of death of the insulin-producing beta cells in the pancreas, and greater gene expression of transcription factors causing formation of fat cells (adipocyte differentiation), which may be a contributor in the development of diabetes and obesity.
The authors also pointed out that recent data revealed epigenetic alterations in the children of smoking mothers – the smoking actually produces changes in the gene expression that may put them at an increased risk for obesity or diabetes later.
They warn though, that uncalculated differences in diet or other factors between families with or without smokers may make up some links that are observed.
The researchers conclude:
“In conclusion, these data show that women exposed to smoking during fetal life are at higher risk of developing gestational diabetes. Although short-term detrimental effects of smoking on the individual and her offspring are well known, such associations might extend into adulthood, making the incentive stronger for undertaking preventable measures, particularly as numbers in some countries point to an increase in daily smoking among young women.”
Written by Kelly Fitzgerald