Putting on too much or too little weight during pregnancy has a negative impact on the child that can be observed when they reach the age of seven, a new study argues.
Women who gained more weight in pregnancy than recommended went on to have seven-year-olds with a larger body size, more body fat, high blood pressure and poor blood sugar control.
“These findings have important implications for both prevention and treatment”
Women who gained less weight than recommended also had seven-year-olds with increased risks of high blood pressure and poor blood sugar control, although not higher body fat.
The study by Professor Wing Hung Tam and Professor Ronald Ma, at the Chinese University of Hong Kong was published in Diabetologia, the journal of the European Association for the Study of Diabetes.
There have been studies looking at gestational weight gain (GWG), but the study authors said little work until now had been done on its metabolic impact on children.
Their research worked with 905 mother-child pairs in Hong Kong who were already enrolled for follow-up visits on the Hyperglycemia and Adverse Pregnancy Outcome study.
Women were classified as having gained weight below, within or exceeding the 2009 Institute of Medicine guidelines. Also factored into the study were standardised GWG values based on pre-pregnancy body-mass index.
“This research highlights the need for guidelines on weight gain in pregnancy in the UK”
The weight change from pre-pregnancy to delivery was 15kg on average, with 17% gaining too little weight, 42% gaining the right amount of weight and 41% gaining too much weight.
“We found evidence of linkage between GWG and several cardiometabolic risk factors in the offspring aged seven years, independently of maternal BMI prior to pregnancy and glucose level during pregnancy,” the study authors said.
“These findings have important implications for both prevention and treatment,” they said. “There is a need for greater awareness and monitoring of weight gain during pregnancy.
They added: “Pregnancy might be a potential window of opportunity for intervention through modifiable behaviours, including maternal nutrition and physical activity.”
However, there were dangers in going to the other extreme and limiting weight gain too much, they warned.
“Although limiting excessive GWG may help minimise the intergenerational cycle of obesity, the benefits of lower weight gain must be balanced against other cardiometabolic risks – such as high blood pressure and poorer blood sugar control – and risk of stunted growth in the offspring if GWG is inadequate,” they said.
They added: “Long-term follow-up of these children is necessary to evaluate the effect of maternal GWG on cardiometabolic risk in adolescence and adulthood.”
Mandy Forrester, head of quality and standards at the Royal College of Midwives, said: “During pregnancy women are very receptive to messages and advice about weight management issues and midwives can have a real impact on improving women’s health and wellbeing.
“This research highlights the need for guidelines on weight gain in pregnancy in the UK,” she said.
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Ms Forrester noted that the RCM, in partnership with Slimming World, had issued a call in July for UK guidelines on what constitutes a safe weight gain.
Without such a move, midwives had to use their own initiative and refer to American guidance, she highlighted.
She said: “There is a clear need for midwives to have the tools, guidance and training they need so that they can offer women the best possible support and care.
“This is especially pressing because of the potentially serious complications that can arise in pregnancy as a result of women being overweight or obese,” she said. “It is a real concern that some midwives do not have access to that most basic piece of equipment, scales.
She added: “We are calling for clear guidance on healthy weight management in pregnancy and will be looking at how we can take this forward so that women and midwives have the information, support and resources needed.”