Overmatige gewichtstoename tijdens zwangerschap geeft zwaardere tieners*
Uit een studie onder bijna 12.000 kinderen blijkt dat overmatige gewichtstoename van de moeder tijdens de
zwangerschap een veel grotere kans geeft op overgewicht van deze kinderen als ze tiener zijn. De normale, gemiddelde gewichtstoename is afhankelijk van de
BMI van de moeder vóór de zwangerschap. Indien deze BMI lager dan 20 is (ondergewicht), dan is een goede gewichtstoename tussen 12,5 en 18 kg. Indien deze BMI 20 tot 25 bedraagt (normaal gewicht), dan is die ca. 12,5 kg. Indien deze BMI hoger is dan 25 (overgewicht), dan is die tussen 7 en 14 kg. ( Tijdens het 1e trimester van een zwangerschap is de gewichtstoename nog gering. Daarna moet het gewicht regelmatig stijgen: 1 kg per maand tijdens het 2e trimester en 2 tot 3 kg in de daaropvolgende maanden.) Kinderen van moeders die duidelijk meer dan de normale gewichtstoename hadden bleken ruim 40% meer kans te hebben op overgewicht als tiener.
Excessive Weight Gain during Pregnancy Leads to Heavier Teenagers
Women, of course, gain weight during pregnancy, though some gain more than others. And, according to a study at the Harvard Medical School, these women may not only have heavier babies, but bigger teenagers, too.
Using data of almost 12,000 children and teenagers, the study found that those whose mothers had put on more than the recommended amount of weight while going through pregnancy had a 42% higher chance of being obese. And this increased likelihood of being heavier was independent of other factors, such as the mothers' weight before pregnancy, family income, as well as the educational level of the
parents.
The study had looked at 11,994 children aged between 9 and 14 whose mothers had been part of the Nurses' Health Study II, a long-term health study of female nurses. In total, 6.5% of the children were obese, and their weight tended to be higher whenever their mothers had exceeded the guidelines for weight gain during pregnancy. By the time they hit 9 to 14 years old, children whose mothers had gained excessive weight during pregnancy were 42% more likely to be obese, as compared to those whose mothers had gained the recommended amount of
weight.
The Institute of Medicine in the United States recommends that a woman in the normal-weight range gain about 25 to 35 pounds during pregnancy. Those who were overweight before pregnancy should, on the other hand, put on less, about 15 to 25 pounds, while those who were underweight before pregnancy should put on 28 to 40 pounds instead.
Previous studies had already linked too much weight gain during pregnancy with higher chances of childhood obesity. With the findings of this latest study, there could well be proof that the fetal environment has a "sustained effect" on children's weight regulation, reported Dr Emily Oken and the study team in the journal Obstetrics &
Gynecology.
Indeed, the study team hypothesizes that excess weight gained during pregnancy may affect fetal development in a manner which then makes the children more likely to gain extra weight. Research carried out on animals, for example, had found that overeating during pregnancy changes certain genetic factors in the offspring, factors which are involved in fat regulation; overeating also seems to have an effect on the parts of the brain which control the
appetite, too.
As far as human beings are concerned, could there be another factor – the fact that parents who have a tendency toward unhealthy and weight-increasing eating habits would end up feeding the same types of food and transmitting the same habits to their children? In my view, this is a highly conceivable
possibility.
In any case, women may want to take note – it is important to enter a pregnancy with healthy weight, and then gain the recommended amount. On top of a better chance for healthy weight for their offspring during their childhood and teenage years, there are numerous other benefits to this advice, both for mothers and
children. (Februari
2009)
