How obesity affects brain development during pregnancy

As families plan to have children, they usually make arrangements to ensure that their offspring will have a good start to life.

Often, parents will begin having conversations about available finances, living conditions and the kind of life they would like their children to have.

And as soon as conception takes place, many usually ensure that they honour all antenatal care (ANC) visits or medical check-ups for assurance that the child is in good health.

In as much as these preparations are important, health expert note that parents should also take into consideration the internal environment that the child is going to grow and develop in.

They state that a mother's health condition before conception plays a key role on the well-being of the child they plan to have.

Among the key health indicators for women is having the recommended healthy weight before pregnancy.

Findings from a new study published in the Journal of Child Psychology and Psychiatry indicate that obese pregnant women could hinder the optimal brain development of their offspring.

Based on the research, this interference on brain development may happen during the early stages of pregnancy, starting from the second trimester.

According to scientists from the New York University (NYU) Grossman School of Medicine who conducted the study, obesity causes changes in two parts of the brain; namely the cortex and anterior insula.

These parts play a key role in decision-making and human behaviour. Research shows that when they are not functioning well, they can lead to conditions such as attention deficit hyperactivity disorder (ADHD), autism and overeating.

ADHD, which is often diagnosed in childhood, is a biological condition linked to inattention and impulsivity, as well as hyperactivity in some cases.

The condition tends to occur more often in males than females.

Its symptoms include the following: constant talking, inability to focus, fidgeting, restlessness and excessive running, jumping or climbing.

On the other hand, autism refers to a range of developmental problems such as restricted or repetitive behaviour, as well as difficulty in socialising and communicating.

Past studies, which have shown that there is indeed an association between obesity and brain development, mostly assessed the brain function of children after birth.

The new study is believed to be the first to measure changes in the brain activity of unborn babies as early as six months into pregnancy.

During the research, scientists recruited 109 women that were either overweight or obese. They were all between six and nine months pregnant.

Being overweight or obese refers to having abnormal or excessive fat accumulation that presents a health risk.

This is usually determined through a test known as body mass index (BMI). It is calculated by dividing a person's weight in kilogrammes by the square of his or her height in metres.

Those found with a BMI of 30 or more are generally obese. Individuals with a score equal to, or more than 25 are considered overweight.

All women who were recruited in the study had BMIs ranging from 25 to 47.

Upon selecting the mothers that were underweight or obese, the scientists went ahead to measure the brain activity of their unborn children using Magnetic Resonance Imaging (MRI).

"Our findings affirm that a mother's obesity may play a role in foetal brain development, which might explain some of the cognitive [brain] and metabolic health concerns seen in children born to mothers with higher BMI," says Dr Moriah Thomason, an associate professor in the Department of Child and Adolescent Psychiatry at NYU Langone Health.

Government statistics from the Kenya Demographic and Health Survey (KDHS) indicate that 33 percent of women in Kenya (between the ages of 15 and 49) are either overweight or obese. And these cases seem to be soaring due to unhealthy diets and sedentary lifestyles.

Since a majority of the affected women are in their reproductive (child bearing ages), health experts note that it is now more important than ever to understand how the condition may impact early brain development.

In spite of the findings, the researchers caution that their study was not designed to draw a direct line between the differences that they found, and ultimate cognitive or behavioural problems in children.

"The study only looked at foetal brain activity. We now plan to follow the participants' children over time to determine whether the brain activity changes lead to ADHD, behavioural issues and other health risks," states Dr Thomason.

Aside from its detrimental effects on brain development, obesity also increases the risk of pregnancy loss (miscarriage) and birth defects of the brain, spine or spinal cord.

To avert these challenges, health experts note that women should ensure that they have a healthy weight before pregnancy. This can be achieved through the help or guidance of a registered dietician.

They can also consult their healthcare providers about safe ways to stay physically active before and during pregnancy such as walking, swimming or doing low-impact aerobics.