Do boys born to obese mothers have ‘worse motor skills and lower IQ scores’?

Researchershave found that a mother's weight during pregnancy can affect her male offspring's development..
Researchershave found that a mother's weight during pregnancy can affect her male offspring's development..

How much a woman weighs when she’s expecting can affect her health and that of her unborn baby. And now researchers from Columbia University Mailman School of Public Health, and the University of Texas (UT) at Austin found a "significant" link between maternal obesity during pregnancy and foetal development – particularly IQ and motor skills. However, this link was only found in boys.

The study analysed 368 mothers and their children during pregnancy, and looked at the children at ages three and seven years. Children at age three years were measured for motor skills, and it was discovered that maternal obesity during pregnancy was strongly associated with lower motor skills.

Motor skills that were tested included dexterity, coordination, movement and speed, and the results indicated that girls had higher scores compared to boys: an average of 102.3, compared to 97.2, and boys whose mothers were obese during pregnancy had a lower score by around eight points compared to boys whose mothers maintained a healthy weight during pregnancy.

At the age of seven, researchers found that the boys who were born to mothers who were overweight or obese during pregnancy had scores of five or more points lower on a full-scale IQ test, compared to boys whose mothers had kept a normal weight. The findings were published in BMC Pediatrics.

‘Not meant to shame mothers’

Co-author of the study Elizabeth Widen, assistant professor of nutritional sciences at UT, said the purpose of the study was not to shame mothers.

“These findings aren't meant to shame or scare anyone. We are just beginning to understand some of these interactions between mothers' weight and the health of their babies,” she said in the article.

However, researchers of the study also pointed out that it's early research and that the mechanisms behind the findings are not clear. The research team advised women who are overweight during pregnancy to consume a well-balanced diet that consists of plenty of fruits, vegetables, fish oils and appropriate supplements. 

Not the first study

Although there is previous research suggesting that a baby's cognition is connected to what the mother eats, the mothers in this study were not asked about their diets.

However, past studies have found that boys appear to be more vulnerable than girls while developing in the womb. A 2010 study notes that boys grow faster than girls in the womb and are therefore at greater risk of becoming undernourished, and that “foetal undernutrition leads to small size at birth and cardiovascular disorders, including hypertension, in later life”.

Another 2013 study published in Pediatric Research found that boys are 14% more likely to be born prematurely than girls. 

Underweight and obesity during pregnancy: the risks

Being both underweight and overweight or obese can pose risks to your pregnancy. While overweight during pregnancy is associated with several pregnancy and childbirth complications, such as high blood pressure and preeclampsia, and an increase in the risk of birth defects, being underweight is similarly dangerous. 

Problems that could arise include the chance of preterm birth and giving birth to a low-birth-weight baby, who may develop health and behavioural problems that could last into childhood and adulthood. 

Healthy nutrition during pregnancy

Factors such as a woman’s body weight; her nutrient intake (including folic acid, omega-3 fatty acids, iron and vitamin B12); exposure to toxins; smoking; drinking and excessive intake of caffeine can all have striking effects on the future of her baby’s health and mental development, dietitian Dr Ingrid van Heerden told Health24

Van Heerden explained that there are certain steps one can take to ensure that thin women gain more weight, and obese women put on less weight during the nine months of their pregnancy. This will ensure that they and their babies have the best chance of future health.

This includes, among others, a sensible approach to physical activity, sufficient protein, appropriate daily energy intake, and the personalised dietary advice of dietitians. You can read more on factors that influence pregnancy outcomes here.

Image: iStock

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