Gestational diabetes along with poverty raises risk of ADHD in the child: Study

By Dr. Ananya Mandal, MDJan 3 2012

According to a new study pregnant mothers with gestational diabetes are more likely to have kids with attention deficit hyperactivity disorder. Additionally if they have a poorer socioeconomic status, the child is 14 times more likely to be diagnosed with the behavioral disorder, researchers at Queens College and Mount Sinai School of Medicine found.

The study, published this week in the Archives of Pediatrics and Adolescent Medicine, found that children whose mothers received a diabetes diagnosis during pregnancy (known as gestational diabetes) were twice as likely as their peers to meet the criteria for attention deficit hyperactivity disorder (ADHD) at age six.

Nomura and her colleagues followed 212 ethnically and socioeconomically diverse children living in Queens, New York, 10% of whom were exposed to gestational diabetes. From preschool through age six, a trained psychologist or doctoral student evaluated each child for ADHD symptoms annually.

The findings don't prove that gestational diabetes directly causes ADHD, but the researchers say they send a message to mothers and doctors that gestational diabetes may pose hidden dangers to a child well after birth, especially if the child grows up in a challenging environment.

“These babies were more likely to grow up to have behavioral and cognitive problems,” said Yoko Nomura, an assistant psychology professor at Queens College. Nomura and colleague Jeffrey Halperin say the key is to raise awareness among parents in the risk groups so they can intervene earlier to treat ADHD. “Mothers should be aware that gestational diabetes can affect her fetus,” Nomura said.

Gestational diabetes affects between 10% and 18% of all pregnancies and can pose serious risks to mother and child if not treated properly. It generally develops during the second or third trimester of pregnancy -- the same window of time in which a fetus undergoes a critical burst of brain development. The number of mothers-to-be who suffer from it is on the rise, fueled by the obesity epidemic and the trend toward later-in-life pregnancies. Women with gestational diabetes have abnormally high blood sugar (glucose). If the fetus is bombarded with excess blood sugar, energy normally used for nervous-system development could potentially be diverted to absorb that excess, Nomura says. As a result, the central nervous system may not develop properly. “When babies are born into higher socioeconomic status households, they have better access to medical care [and] remedial activities, intellectual stimulus is higher, they have better foods,” Nomura says.

In addition, low-income women may not control their gestational diabetes as well as more prosperous mothers-to-be, says Luigi Garibaldi, M.D., clinical director of pediatric endocrinology at the Children's Hospital of Pittsburgh. “Having diabetes during pregnancy by itself may not be so bad, but if you don't take care of it, there may be consequences on the brain development of the child,” says Garibaldi, who was not involved in the study.

“A mother who suffered from gestational diabetes is more likely to experience the same thing in her next pregnancy,” said Nomura. “Letting her know the risks to the baby during and after the birth can make a big difference.”

The study had several shortcomings. It was relatively small, and although they did take into account the parents' history of ADHD, the researchers didn't collect data on whether the children had siblings or other relatives with attention or hyperactivity problems. Also, Garibaldi notes, the researchers didn't measure how well the mothers controlled their gestational diabetes.

Still, the study is a valuable reminder that a child's environment - in and out of the womb - appears to affect the risk of ADHD, says Joel Nigg, a professor of psychiatry at Oregon Health & Science University, in Portland. Previous research suggests, for instance, that children are at increased risk of ADHD if they're exposed to lead and certain pesticides. “As a precaution, we might want to add [gestational diabetes] to the list of risk factors we're aware of,” says Nigg, who wrote an editorial accompanying the study.