“Big babies become big children and big adults later on,” says Professor Lesley McCowan from the Department of Obstetrics and Gynaecology at The University of Auckland. “If we can reduce that happening, we can have a big public health impact.”
A recent study, led by Professor McCowan, showed that 74 percent of women pregnant for the first time, gained excessive amounts of weight during their pregnancies. These women had a four-fold increase in the proportion of infants who were excessively large at birth and an increased number of caesarean deliveries in labour.
“Babies born large are at risk of traumatic birth, and caesarean delivery increases the chance of complications for the mother,” says Professor McCowan. “These adverse outcomes can be modified by achieving optimal weight gain in pregnancy. This should be an important focus of ante-natal care.”
“If we can optimise weight gain during pregnancy, we can also eliminate an important cause of obesity in women,” she says. “Most women who gain too much weight are not able to lose that weight after pregnancy and it puts those women on a trajectory to becoming obese”.
Each time women have a baby, they tend to gain more weight. We need to attend to the mother’s health to stop her becoming obese and it is vitally important for long term health of the baby too, says Professor McCowan. Women in the study who gained excessive weight had a four-fold increase in the proportion of infants who were excessively large at birth and an increased number of caesarean deliveries in labour. The women most likely to have high gestational weight gain were those who were overweight or obese when they became pregnant, she says.
“The findings are important for the health of the mothers as well as the babies,” says Professor McCowan. “Excessive weight gain during pregnancy will not only exacerbate existing obesity, but will contribute to later obesity in women who start pregnancy with a normal body mass index but have excessive weight gain in pregnancy.”
“Overall this leads to increased incidence of non-communicable diseases in these women and increased health care costs for society, as well as potentially adverse effects on their children throughout their lives.”
If women enter pregnancy overweight or obese, they cannot reverse that during pregnancy, but with appropriate nutritional intervention, the amount of weight a mother gains can be optimised, she says.
“Nutritional interventions can limit weight gain and improve pregnancy outcomes by reducing the chance of a big baby and also reduce the chance of the mother developing gestational diabetes and pre-eclampsia, conditions which can have lifelong consequences for mother and baby”.
The small group of women who gained less than the recommended amount of weight in McCowan’s study had a higher proportion of babies who were “small for dates”. Babies born small for dates have an increased risk of stillbirth and complications in later life such as cerebral palsy and cardiovascular disease.
The study was conducted by the international SCOPE Consortium, which aims to develop effective ways of predicting and preventing complications of pregnancy. The weight of the women was recorded at 14 to 16 weeks into the pregnancy and again just before delivery. Of 1,950 participants – from Auckland, Adelaide and Cork in Ireland – 17.2 percent achieved the recommended pregnancy weight gain, while 8.6 percent gained less weight than the recommended amount and 74.3 percent gained an excessive amount.
The University of Auckland