The proportion of pregnant women with obesity (body mass index [BMI] above 30 kg/m2) has doubled over the past decade, from around 22% in 2010 to 44% in 2018, according to new research being presented at this year's European Congress on Obesity (ECO) in Glasgow, UK (28 April-1 May).
The findings also reveal rising incidence of caesarean section births alongside increasing BMI. In 2018, approximately 1 in 4 pregnant women with a normal BMI (BMI 18.5-25 kg/m2) had a caesarean section compared with more than 1 in 2 pregnant women with morbid obesity (BMI above 40).
"These latest figures are concerning and show how much of a worsening problem obesity in pregnancy has become. This may reflect changes across the UK," says Dr Laura Jane Erunlu, University Crosshouse Hospital, Kilmarnock, Scotland who led the research.
The prevalence of obesity within the UK has increased markedly over the past 30 years. In 2010, almost half of pregnant women in Scotland were overweight or obese with 1 in 5 classed as obese .
"Measures to try and halt or reverse this trend are paramount. Even prior to conception women need to be thinking about maintaining a healthy weight, exercising, and eating healthily to give their baby the best possible start in life."
Obesity in pregnancy substantially increases the risk of maternal complications such as gestational diabetes, pre-eclampsia, and miscarriage . Obesity can also cause problems for the baby such as a larger birth weight. The MBRRACE-UK review found that over half (52%) of pregnant women who died in the UK and Ireland between 2009 and 2012 were overweight or obese . In this study, Erunlu and colleagues aimed to quantify maternal obesity prevalence and trends at the Ayrshire Maternity Unit in Kilmarnock, Scotland that serves a population of 400,000 people and delivers around 3000 babies each year.
"Pregnant women now tend to be older, heavier, and have more complex medical histories when they become pregnant. These complications pose specific challenges to our maternity services, and we must shape our healthcare services with this changing demographic in mind", says Dr Erunlu. "Both increasing BMI and the rising incidence of caesarean section in pregnant women with obesity mandate a greater need for obstetric theatre services and accompanying medical and nursing staff."
The authors acknowledge that their findings are limited by the fact that it is a retrospective observational study. The data set was reliant upon accurate data entry by clinical staff. The electronic record was introduced in 2009 and therefore we expect that data quality immediately after its introduction may be less accurate.