Poor Health Outcomes in Pregnancy for Obese Women
3 February 2011
Major Study Finds Poor Health Outcomes in Pregnancy for Obese Women
A major New Zealand study warns obese pregnant women of the increased risk of pregnancy complications.
Findings from The SCOPE study researched the link between obesity in pregnancy and the related complications for mother and baby in more than 3,000 Australian and New Zealand pregnant women. They were presented by Royal Australian & New Zealand College of Obstetricians and Gynaecologists (RANZCOG) Fellow Professor Lesley McCowan at a recent RANZCOG conference which focused on obesity in pregnancy.
These findings have been backed up by a three-year UK-wide national survey run by the Centre for Maternal and Child Enquiries (CMACE).
Professor McCowan says both studies show obese women in New Zealand and the UK face an increased risk of caesarean section and preeclampsia. Preeclampsia is a severe hypertensive condition which can be dangerous for the mother and result in lifelong consequences for the baby who is more likely to be born preterm or undernourished.
“The SCOPE study found that 25 per cent of overweight women and 36 per cent of obese women who went into labour at full term delivered by caesarean compared to 18 per cent of women with a normal body weight. The UK study showed that only 55 per cent of women with a Body Mass Index (BMI) greater than 35 gave birth naturally. These findings are important as caesarean delivery in bigger women is associated with higher risks and also increased health care costs.
“The risk of preeclampsia also increased with increased BMI. We found that overweight women have a 5.7 per cent chance of developing preeclampsia and this increased to 10.7 per cent in obese women versus 3.9 per cent in those with a normal weight.”
Professor McCowan says other complications which are more common in big mothers include gestational diabetes, induction of labour, pulmonary embolism, postpartum haemorrhage and infection.
“In addition the baby has an increased risk of congenital abnormality, being stillborn or dying in the neonatal period, and being overweight at birth. These overweight babies are more likely to grow up and become obese children. Obese women are also less likely to successfully breastfeed their babies which is important as breastfeeding reduces the risk of childhood obesity.”
Professor McCowan says the studies demonstrate the link between obesity and poor health outcomes in pregnancy which is a health issue across all Western countries especially in those with an obesity rate higher than the OECD average. These countries include the US, the UK, Australia and New Zealand.
“The rate of these complications is likely to continue to increase as obesity levels continue to rise. New Zealand health data from a 2006-2007 survey found that 55 per cent of adult women are overweight or obese.
Professor McCowan says the good news is that if obese women gain a limited amount of weight during their pregnancy they can improve outcomes for them and their babies. This does not mean dieting but adopting healthy eating with home cooked meals, no soft drinks or juices, limiting highly processed foods and smaller portion sizes.
“The current recommended weight gain during pregnancy is between 11.5-16 kg for a normal weight, 7-11kg for an overweight women and 5-9kg for women with a BMI of more than 30.”
Obesity is defined as having a Body Mass Index (BMI) of >=30, with an ideal weight being a BMI of 20-24.9.