A new study suggests that a woman’s risk of having a baby with congenital kidney and urinary tract defects is higher when she is obese. These birth defects include everything from single kidney, kidney swelling, enlarged ureters, or urine-carrying tubes, lead researcher Dr. Ian Macumber said.
Dr. Macumber, the pediatric nephrology fellow at Seattle Children’s Hospital explained that obesity is severely underestimated as a public health issue. The more scientists study it, the more they find out he said.
Other studies have already connected maternal obesity to newborn heart defects, neural tube defects, spina bifida as well as many other conditions. However, the connection to congenital kidney and urinary tract defects is newer.
“We found a significant association between maternal obesity and risk of these anomalies,
The relationship between the two was, however, not a cause-and-effect type of relationship.
Macumber and his team investigated birth defects occurring in up to 1 percent of all pregnancies. Kidney defects and urinary tract abnormalities account for approximately 20-30 percent of all prenatal abnormalities, and the team found that the risk of such defects occurring increased along with the level of obesity.
Over 50 percent of all pregnant American women are overweight or obese. Eight percent of reproductive-aged women are in the extremely-obese category.
Results of the study will be presented on November 14th at the American Society’s of Nephrology meeting in Philadelphia, before it is published in a peer-reviewed medical journal.
Researchers analyzed more than 3,200 cases of abnormal kidney or urinary tracts, and compared these patients with over 13,000 “control subjects”- newborns with no birth defects. This patient information was included in the birth and hospital discharge records spanning across 9 years, from 2003 to 2012.
According to this information, pre-pregnancy weight records showed that in the case of babies being delivered with the birth defects, their mothers were 1.3 times more likely to be obese as opposed to those with no defects.
“There is certainly some question as to whether insulin may play a role in this,”
Macumber said, as the research team hasn’t yet determined a mechanism explaining the association.
Dr. David Mendez, attending physician at the Miami Children’s Hospital as well as neonatologist explained that such studies represent an essential part of doctor’s work. They are, in his view a good starting point, although limited in such repsects.
Ideally, he said, prospective studies should also be conducted to follow mothers during pregnancy, to assess the link from the start.