Mothers and offspring benefit from physical activity and changes in diet
The study, published today in the British Journal of Medicine (BMJ), is the largest research project in the world looking at lifestyle interventions in pregnancy. It compared the effects of dieting and physical activity to gestational weight gain and the health of the mother and the child. According to the results, the lifestyle interventions reduced the mother’s weight gain during pregnancy, the likelihood of the mother having a caesarean section and the risk of diabetes in pregnancy. Furthermore, the interventions did not negatively affect the baby’s health.
The research project is conducted by a broad iWIP (International Weight Management in Pregnancy) network that includes over 50 researchers from 41 different institutions. The research looked at the individual participant data for 12,526 pregnant women across 36 previous trials in 16 countries. In the research project, Finland was represented by the Neuvonta, Elintavat ja Liikunta neuvolassa (NELLI: Counseling, lifestyle and physical activity in maternity care) research project that is being conducted at the UKK Institute in Pirkanmaa since 2003 and is led by Research Director Riitta Luoto from the University of Tampere.
“The NELLI research project is one of the first research projects looking at preventing gestational diabetes internationally and was followed by dozens of similar studies around the world. In these studies, nutritional advice and physical activity guidance were used to improve the lifestyle of pregnant women and thus to prevent excessive weight gain during pregnancy as well as gestational diabetes. In the iWIP research project, the data of dozens of research projects was combined and then analysed as an entirety, which led to great generalisability,” says Luoto.
Half of all women of childbearing age worldwide are overweight or obese, which puts both the mother and the offspring at risk in pregnancy and later life. Previous studies have found that diet and physical activity have an overall beneficial effect on limiting weight gain during pregnancy, but findings have varied for their protective effect on maternal and offspring outcomes.
According to the results, dieting combined with physical activity significantly reduced the mother’s weight gain during pregnancy by an average of 0.7 kg compared to the control group and lowered the odds of the mother having a caesarean section by about 10 per cent. Changes in lifestyle reduced the risk of diabetes in pregnancy by 24 per cent. Normally, over one in ten mothers suffer from gestational diabetes which increases the risk of complications in both the mother and the baby.
According to Professor Shakila Thangaratinam, who leads the research project, the results are important because it is often thought that pregnant women should not exercise because it may harm the baby. However, according to the results, physical activity or changes in diet do not affect the baby and they can be used to prevent weight gain during pregnancy, gestational diabetes and caesarean sections.
“This should be part of routine advice in pregnancy. Now that we are able to prove the benefits of advice for mothers-to-be, we hope mothers are more likely to adopt these lifestyle changes,” says Thangaratinam from the Barts Research Centre for Women’s Health of the Queen Mary University of London.
According to Professor Thangaratinam, these interventions often benefit certain groups more than others, but the results prove that a healthy diet and physical activity have beneficial effects across all groups, irrespective of body mass index (BMI), age or ethnicity. These interventions thus have the potential to benefit a large number of people.
There was no strong evidence that the interventions affected offspring outcomes such as stillbirth, underweight or overweight births, or admission to a neonatal intensive care unit. The lack of adverse effects should reassure mothers who have traditionally been advised not to undertake structured exercise or manage their diet in pregnancy.
The study was funded by the Health Technology Assessment (HTA) programme of the National Institute for Health Research (NIHR). The Finnish NELLI research project, which is funded by the Academy of Finland, has pioneered in follow-up research of mothers and children later in life. In 2014, a follow-up study looking at lifestyles and health was initiated with the mothers and children who participated in the NELLI research project in 2007–2009. The children were 5–7 years old in 2014.
For further information, please contact:
Research Director Riitta Luoto, puh. 050-4648482, Riitta.Luoto@uta.fi
For further information on the follow-up study (in Finnish), please see: http://www.ukkinstituutti.fi/terveysliikuntanyt/aihe/ajankohtaista/308/nelli-seurantatutkimus_pirkanmaalla
For further information on the NELLI research project (in Finnish), please see: http://www.ukkinstituutti.fi/tutkimus/tutkimushakemisto/33/neuvonta_elintavat_ja_liikunta_neuvolassa_raskausdiabeteksen_ehkaisytutkimus
The Facebook page of the NELLI research project (in Finnish): https://www.facebook.com/nellitutkimus/