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RCOG statement on gestational weight gain or loss and adverse outcomes

News 7 June 2017

In an analysis of more than 1.3 million pregnancies, weight gain during pregnancy greater or less than US guideline recommendations was associated with a higher risk of adverse outcomes for mothers and infants, according to a study published by JAMA.

Body mass index and gestational weight gain are increasing globally. In 2009, the US Institute of Medicine (IOM) provided specific recommendations on the ideal gestational weight gain. Researchers carried out a systematic review and meta-analysis of 23 studies to evaluate associations between gestational weight gain above or below the IOM guidelines and maternal and infant outcomes.

They found that 47% of pregnancies had gestational weight gain greater than IOM recommendations and 23% had weight gain less than the recommendations. Gestational weight gain below the recommendations was associated with higher risk of a small baby and preterm birth. Gestational weight gain above the recommendations was associated with higher risk of a large baby and caesarean delivery.

Dr Daghni Rajasingam, spokesperson for the Royal College of Obstetricians and Gynaecologists (RCOG), said: 

“The results of this large scale study highlight the potential complications for mother and baby if a woman gains more or less weight in pregnancy than is recommended by the US Institute of Medicine (IOM), including having large or small babies, preterm birth and caesarean delivery.

“These findings have relevance in the UK as one in five pregnant women are obese and illustrate the importance of maintaining a healthy lifestyle through a well-balanced diet and exercise before, during and after their pregnancy to reduce associated complications. It is a myth that women need to ‘eat for two’ during their pregnancy - energy needs do not change until the last three months of pregnancy, when women need an extra 200 calories a day. Having a normal bodyweight will help to increase the chances of conceiving naturally and reduces the risk of pregnancy and birth complications for the mother and baby.”



For media enquiries please contact the RCOG press office on +44 (0)20 7045 6773 or email