Study: Obesity during pregnancy increases risk of epilepsy in child

A study of more than a million children has found the risk of epilepsy almost doubled among those born to severely obese mums.

Being overweight during the first trimester of pregnancy has been linked to an increased risk of childhood epilepsy.

The recent Swedish study, published in journal JAMA Neurology, of almost 1.5 million babies found the risk of epilepsy almost doubled from normal-weight women to very severely obese women.

Epilepsy disrupts the normal electrochemical activity of the brain resulting seizures.

The cause of this debilitating and often hard-to-treat condition is poorly understood.

With obesity on the rise, there is growing concern about the long-term neurological effects of children exposed to maternal obesity in pregnancy.

"Given that overweight and obesity are potentially modifiable risk factors, prevention of obesity in women of reproductive age may be an important public health strategy to reduce the incidence of epilepsy," the authors wrote.

Researchers at the Karolinska Institutet in Stockholm studied live-births in Sweden between 1997 and 2011. Of those they studied, there were 7,592 babies, or 0.5 per cent, diagnosed with epilepsy.

The risk of epilepsy increased by 11 per cent among those born to overweight mothers — those with a body mass index of 25-29 — compared with children of normal-weight mothers.

Grade I obesity (BMI 30 to less than 35) was associated with a 20 per cent increased risk, grade II obesity (BMI 35 to less than 40) was associated with a 30 per cent increased risk.

Babies born to severely obese mums, or grade III obesity, was associated with an 82 per cent increased risk of epilepsy.

You can calculate your BMI on the Government's Health Direct website.

Bernadette White, the clinical director of obstetrics at the Mercy Hospital for Women in Melbourne, said the study definitely piqued her interest.

Did the findings surprise her? Not exactly.

"In some ways it's not all that surprising because [the study's authors] mention some of the reasons for the link are things we already know to be associated with obesity, like neuro abnormalities and greater risks of diabetes," Dr White said.

"It sheds more light on the complexity of obesity and how many implications it has."

We know there's a link, but what's the cause?

While this study appears to have found a link between obesity during pregnancy and epilepsy, the causal connection remains to be proven.

One possible reason for this increased risk, according to the authors of the study, is that being overweight or obese may increase the risk of brain injury, leading to a range of neurodevelopmental disorders and epilepsy could result from that disorder.

Another possible reason is that maternal obesity might affect neuro-development through obesity-induced inflammation.

Dr White said that, while offering theories, finding the causal link between obesity and epilepsy needed further investigation.

"One of the things becoming apparent with obesity is that its a complex condition," she said.

"We already know obesity during pregnancy can lead to an increase in high blood pressure and that obese women may require injections of folic acid … and that obesity is linked to increased complications in pregnancy."

She believes that while studies like this reinforce to women that obesity is not healthy, it could come across as fodder — just another risk in a long line of health risks.

"I think it's one more thing to tell obese women but it's not going to change these women," Dr White said.

Instead, Dr White believes getting a better understanding of the cause of obesity and epilepsy could lead to finding other ways of trying to break the link, rather than telling women they need to lose weight.

What about the case for obese women to access IVF?

Currently, obese women face obstacles in getting IVF treatment because doctors are advised not to provide the treatment to obese women because of numerous risks for the mother and baby.

Recently, the ABC spoke to Kelton Tremellen from Flinders University, who believes the guidelines for IVF need to be revised to improve access for obese women.

When questioned on whether obese women should have access to IVF in light of the new research, Dr White said it would not change anything.

"It comes down to an ethical debate rather than a medical one."