“Big babies become big children and big adults later on,” said Professor Lesley McCowan, of Auckland University’s Department of Obstetrics and Gynaecology. “If we can reduce that happening, we can have a big public health impact.”
The study, led by McCowan, showed that almost three-quarters of women who were pregnant for the first time gained excessive amounts of weight during their pregnancies. These women also had a fourfold 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,” said McCowan. “These adverse outcomes can be modified by achieving optimal weight gain in pregnancy. This should be an important focus of antenatal care.”
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 the 1,950 participants, from Auckland, Adelaide and Cork in Ireland, just over 17% achieved the recommended pregnancy weight gain, while 8.6% gained less weight than the recommended amount and 74.3% gained an excessive amount.
According to the researchers, this study is important for the health of the mothers as well as their babies, not least as it found that excessive weight gain during pregnancy would not only exacerbate existing obesity, but would also 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,” said McCowan.
Significantly, 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.
“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 study revealed.
Conversely, the small group of women who gained less than the recommended amount of weight the study had a higher proportion of babies who were “small for dates”. Babies born in this way have an increased risk of stillbirth and complications in later life such as cerebral palsy and cardiovascular disease.