Are Bigger Babies Better? You decide...

Recent studies show that Canadian babies are getting bigger. And not just Canadian babies. American, Australian, and European babies too.

Statistics Canada’s birth weight records from 1970 to 2003, show that the percentage of baby boys born weighing 8 lbs 13 oz or more, rose from 10% to nearly 16%! On average, boys weigh 3½ oz more than girls at birth, but the percentage of female babies over 8 lbs 13 oz nearly doubled during the same time period.

Michael Kramer, who is a professor of paediatrics, epidemiology and bio-statistics at McGill University, studied the weight of babies born from 1978 to 1996 at a Montreal hospital. He discovered that on average, babies born at 37 weeks in 1996 weighed 2 oz more than their counterparts did 18 years earlier. Although this may not sound like a lot, it is. Considering that during this period the number of overdue deliveries went down, and the number of pre-term births went up. Both of these factors should have resulted in smaller babies. Despite this, the average birth weight has gone up.

In trying to figure out why, he analyzed the mother's weight and height pre-pregnancy, weight gain during pregnancy, smoking habits, and incidence of gestational diabetes (a condition where the mother’s increased blood sugar circulates in the baby, leading to excessive growth and more fat) .

What he found was that far fewer Canadian women smoke during pregnancy, a change that has brought many health benefits, and, bigger babies. Also, a rise in gestational diabetes rates. Women having babies over age 35 are at higher risk for gestational diabetes. In 1991, about 33% of Canadian babies were born to women aged 30 and over. Now 50% of babies are born to mothers 30 and older. Prenatal weight gain and the mother's pre-pregnancy weight may also affect a baby’s size. Women do gain more during pregnancy than they did 20 years ago, but the key factor contributing to larger babies, is probably not a woman’s weight gain during pregnancy, but her weight before. A mother’s size has far more effect on how big her baby will be than a father’s size does. Small women tend to have smaller babies and large women tend to have larger babies. Formula fed babies are also found to be bigger than breast-fed babies, however, but whether babies are breastfed or bottle-fed, according to Kramer, "it’s what happens after weaning that really matters".

No one is suggesting we should strive for underweight babies by any means. But, big babies can present big problems during labor and delivery, and a high birth weight can also affect the rate of weight gain in childhood too. While babies do need relatively more fat than kids or adolescents, they can however have too much. "Larger babies are more likely to be obese kids and, therefore, obese adults." says Kramer. And "children who gain a lot of weight quickly are at a greater risk of obesity, heart disease and diabetes later in life".

Childhood obesity is currently at epidemic levels, according to the World Health Organization. It affects an estimated 17.6 million children worldwide. But are bigger babies doomed to a future of fat and illness? No. A high weight gain rate is nothing to worry during the first year of life. And although a big baby has a higher likelihood of becoming obese than a thin baby does, most overweight babies will not be overweight adults. That’s positive news for parents because they have the power to determine their children’s future health.

So, what do YOU think?