Maternal smoking ups risk of short stature, obesity in adult daughters
Daughters of mothers who smoked early in pregnancy appear to be shorter in stature and heavier during adulthood compared to those of nonsmokers, according to a Swedish study.
“Overall, our results emphasize the importance of early intervention for women who smoke to reduce the long-term health risks to their offspring,” researchers said. “We showed that smoking in early pregnancy was associated with an increased risk of obesity and short stature in adult life.”
Anthropometry in 22,421 daughters was assessed in association with their mother’s tobacco smoking early in pregnancy (at their first antenatal visit), particularly their risk of short stature and obesity.
Researchers grouped adult daughters according to maternal smoking levels during pregnancy: nonsmokers (58.5 percent), light smokers (24.1 percent; smoked 1–9 cigarettes/day) and heavier smokers (17.4 percent; smoked ≥10 cigarettes/day). They recorded anthropometry on adult daughters at about 26.0 years of age.
Obesity was defined as body mass index (BMI) ≥30 kg/m2 and short stature as height more than two standard deviations below the population mean.
Mothers who were light and heavier smokers in early pregnancy had daughters who were 0.8- and 1.0-cm shorter, 2.3- and 2.6-kg heavier, and had 0.84- and 1.15-kg/m2 greater BMI, respectively, than those of nonsmokers. [Sci Rep 2019;9:4290]
Irrespective of smoking levels, there was a 55-percent higher adjusted relative risk of short stature in women born to smokers. In addition, the association of maternal smoking with obesity risk was dose-dependent, with offspring of heavier and light smokers being 61- and 37-percent more likely to be obese than those of nonsmokers.
In earlier longitudinal studies, findings showed an increased risk of obesity in children born to mothers who smoked during pregnancy as they got older. [Int J Obes 2011;35:53-59; Pediatr Obes 2014;9:e14-e25; BMJ 1988;297:1233-1236]
“The results of our study confirm previous research reporting that the increased risk of obesity for offspring of women who smoke while pregnant persists into adulthood, although the relationship may not be as strong as in childhood,” researchers said. [Int J Epidemiol 2001;31:413-419; Diabetologia 2013;56:1689-1695]
Although there were no reports of adult outcomes comparing maternal smoking in early vs late pregnancy, a German study suggested that the risk of childhood obesity might be similar between offspring of women who quit smoking early in pregnancy and those whose mothers continued smoking throughout pregnancy. [Am J Epidemiol 2003;158:1068-1074]
“In contrast, it seems that the relationship between maternal smoking and lower birthweight appears to be strongest when smoking continues into the third trimester, the time when most foetal growth occurs,” researchers said. [Matern Child Health J 2015;19:447-458]
“[S]moking cessation messages should target in particular younger women who may become pregnant, and medical providers should be unequivocal in expressing the risks of smoking during pregnancy for offspring health,” they added.