Newborns of mothers who were overweight or obese during pregnancy have thicker aorta walls compared to infants born to women with a normal body weight, according to a new study by the University of Sydney.
The researchers reported that the thickening of the body’s major artery — the aorta — occurred irrespective of the baby’s birth weight. They warned that this is a major risk factor for later heart disease and stroke.
The study published online in the Fetal and Neonatal Edition of Archives of Disease of Childhood involved 23 pregnant women aged between 27 and 44.6 years. These women were recruited during their 16th week of gestation from The Women’s Hospital in Melbourne, Australia. The scientists defined a body mass index (BMI) of over 25kg/m2 as overweight or obese. The BMI of women in the study group ranged from underweight (17 kg/m2) to seriously obese (42 kg/m2).
Ten of the newborns were boys and the birth weight of all the babies varied from 1.85kg to 4.13kg.
Within seven days of each birth, the scientists scanned the baby’s abdominal aorta — the section of the aorta extending down to the belly — to determine the thickness of the intima and media walls, the two innermost walls of the artery.
The scans revealed that the intima-media thickness, which ranged from 0.65mm to 0.97mm, was associated with the mother’s weight. The higher the mother’s weight, the greater was her baby’s intima-media thickness. This was observed independently of the newborn’s birth weight.
The researchers concluded that this finding could explain how excessive weight during pregnancy can increase the baby’s susceptibility to cardiovascular disorders later in life.
The difference in intima-media thickness between newborns of overweight and normal weight mothers was 0.06mm.
“The earliest physical signs of atherosclerosis are present in the abdominal aorta, and aortic intima-media thickness is considered the best non-invasive measure of structural health of the vasculature in children,” report the study authors.
However, for a more solid conclusion, this research needs to be replicated on a larger scale and the babies would have to be followed for a longer time to investigate their heart health. Moreover, some of the mothers included in the study were smokers and others developed high blood pressure or diabetes during their pregnancy. It is possible that these factors may have influenced the results.
Maternal excess body weight and long-term health consequences in offspring
Although further research is warranted, this study adds to an already large body of evidence that the mother’s weight prior to and during pregnancy may have long-term health repercussions on her baby.
For instance, after analysing 30 studies involving a total of 200,000 participants, Nottingham University researchers found that babies born to overweight mothers were more likely to be overweight themselves during their childhood and teens. Previous research has linked childhood obesity to several diseases such as diabetes and heart conditions.
And a 2010 US study linked obesity during pregnancy to a 33 percent higher risk of having a baby with a heart defect.
Overweight or obese women who look forward to having a baby are therefore strongly advised to attain a normal body weight before trying for a baby.
Begg et al (2013) Maternal adiposity and newborn vascular health. Arch Dis Child Fetal Neonatal Ed. 98(3):F279-F280.