UK scientists are predicting that by 2010 over one fifth of pregnant women in the UK will be obese at the start of their pregancy. This puts an enormous strain on the pregnancy, increasing the risk to the health of both mother and baby.

The study is published in the BJOG: An International Journal of Obstetrics and Gynaecology.

The research team comprised scientists from the North East Public Health Observatory NEPHO), based in Teesside, UK. The NEPHO has a special interest in studying the prevalence of obesity in the North East UK because it has been increasing at a higher rate than the national average.

They studied the records of 36,821 women who had attended a local maternity unit between the start of 1990 and the end of 2004 (15 years). They used statistical regression methods to look for correlations between maternal obesity and demographic and socio-economic variables over the 15 year period. They used National Census data to put the local data in the context of the general population.

The results showed that the percentage of women who are obese at the start of their pregnancy rose from 9.9 to 16.0 per cent in the 15 year period. Using a quadratic statistical model the researchers showed that the rate is accelerating, that is the speed of the growth is getting bigger each year. The incidence of obesity in newly pregnant women is predicted to be 22 per cent if the trend continues.

The results also showed a significant correlation between maternal obesity at start of pregnancy and living in a deprived area, and also with being older. Women from poorer areas were twice as likely to be obese at time of conception.

Pregnant women who are obese have a greater risk of miscarriage, get blood clots, suffer from pre-eclampsia (high blood pressure with too much protein in the urine). They are also more likely to give birth by Caesarean . Accroding to a Confidential Enquiry into Maternal and Child Health (CEMACH) report, 35 per cent of women who had a pregnancy-related death were obese. Babies born to obese mothers also tend to be larger and have a slightly higher risk of dying.

"Maternal obesity is something that has crept up on us," said one of the study team, Professor John Wilkinson who is Director of the NEPHO.

The researchers draw attention to the bigger load this will place on maternity services and called it a serious "public health time bomb". They called for public health interventions to try and reverse the trend.

"Trends in maternal obesity incidence rates, demographic predictors, and health inequalities in 36 821 women over a 15-year period."
N Heslehurst, LJ Ells, H Simpson, A Batterham, J Wilkinson, CD Summerbell.
BJOG: An International Journal of Obstetrics and Gynaecology 114 (2), 187-194.
doi:10.1111/j.1471-0528.2006.01180.x

Click here for Abstract.

Maternal Obesity & Pregnancy Outcome Project Information Sheet (North East Public Health Observatory, UK)

: Catharine Paddock
Writer: blog