Page URL:

Overweight women risk their IVF chances

21 October 2009
Appeared in BioNews 531

Women who are overweight or obese have lower chances of successful IVF treatment, according to researchers reporting at the American Society for Reproductive Medicine (ASRM) conference in Atlanta, US, this week. The researchers, from Michigan State University in the US, found that women who were defined as clinically obese were up to 35 per cent less likely to conceive and have a live baby, and twice as likely to have a stillbirth, than their lighter counterparts.

Women who were classed as overweight were 13 per cent less likely to conceive and were 16 per cent more likely to have a premature birth than those of normal weight. The study involved nearly 50,000 women who were grouped according to their body mass index (BMI), which is calculated as weight in kilograms divided by height in meters squared. Those with a BMI between 20 and 25 were considered to be normal weight, those between 25 and 30, overweight, and those above 30, obese.

Dr Barbara Luke, who led the study, said that 'the take-home message from this is that women need to reduce their weight before trying fertility treatment'. She added: 'Obesity is a state of inflammation and increasing obesity is not good. It is not conducive to conception and it is not conducive to pregnancy'. Women in the study with a BMI between 30 and 34.9 (5187) had nine per cent less chance of getting pregnant, a 20 per cent lower chance of a live birth, were on average 33 per cent more likely to have a premature birth and had more than double the risk of a stillbirth. Tam Fry, from the National Obesity Forum, said that 'this study underlines the fact that if you are thinking about having children, you should start thinking about losing weight at least six months before you conceive.'

More than one in four Britons is now thought to be obese and that figure rises year by year. Around 3.5 million people in Britain experience fertility problems at some stage, and most NHS hospitals will not fund fertility treatment for women with a BMI of 30 or more. The British Fertility Society recommended two years ago that women with a BMI over 35 should not receive fertility treatment until they had lost weight.

A recent Australian survey showed that women who are overweight or obese often do not realise they are. In a study of 412 women, 30 per cent of whom were overweight or obese, only 36 per cent said they believed their weight to be normal, and only 16 per cent acknowledged that they were obese.

The results of a Scottish study, reported in BioNews in January, contradict the US researchers findings. It showed that obese and overweight women had the same chances of successful IVF treatment as normal weight women. The only difference noted in that study, similar to the current research, was the higher rate of miscarriage in heavier women.

Is obesity so common it's now seen as normal?
The Orlando Sentinel |  20 October 2009
Obese IVF women 35% less likely to conceive
Metro |  20 October 2009
Overweight women putting chance of having children at risk
The Daily Telegraph |  20 October 2009
17 September 2012 - by Sarah Pritchard 
The eggs of women undergoing IVF are significantly more likely to contain chromosomal abnormalities if the woman is severely obese than eggs belonging to women who are of a healthy weight, a recent US study suggests...
10 October 2011 - by Dr Marianne Kennedy 
Being just slightly overweight can affect the chance of having a baby through IVF, according to a study at Guy's and St Thomas' NHS Foundation Trust....
22 August 2011 - by Dr Lux Fatimathas 
European researchers have shown a correlation between impaired embryo development and the fat levels of mother cows. Exposing eggs to high levels of saturated fatty acids affected the health of embryos produced by fertilising those eggs...
28 June 2010 - by Dr Charlotte Maden 
Women using assisted reproductive technology (ART) to conceive have a higher rate of miscarriage if they are overweight, say a group of UK scientists....
30 November 2009 - by Nishat Hyder 
A central London fertility clinic is offering an IVF treatment package in return for patients signing up to a health and lifestyle improvement programme, which will require patients to stop smoking, drinking, and lose weight if necessary prior to commencing IVF treatment....
16 February 2009 - by Misty Hatfield and Dr John MacMillan 
Dian Shepperson Mills' 'Commentary' in BioNews 493 (2/2/2009) 'Why fertility patients should consider what they eat before resorting to more invasive treatment' directs us to observational studies on the links between diet and (in)fertility as well as pregnancy outcomes. Since the original observations were made in the...
4 January 2009 - by Sarah Pritchard 
The results of a study in Scotland have indicated that obese and overweight women have the same chance of successful IVF treatment as normal weight women. The research was undertaken in Aberdeen between 1997 and 2006, on 1,700 women undergoing their first cycle of IVF, and included...
28 July 2008 - by Dr Mark Hamilton 
The publication at the end of last week of the results of a survey conducted by the British Fertility Society (BFS) in collaboration with the Science Media Centre provoked widespread media interest. Coinciding with the 30th Anniversary of the birth of Louise Brown, the exercise attempted to provide insight in...
4 September 2006 - by Tom Parkhill 
The media storm over the British Fertility Society's statement on social values took us all by surprise. We had issued a press release about a forthcoming paper in the journal Human Fertility, commenting on the lack of implementation of NICE fertility guidance by Primary Care Trusts (PCTs), and making some...
24 February 2006 - by BioNews 
The Fertility Society of Australia (FSA) is planning an advertising campaign warning of the factors that can affect fertility, the Age newspaper reports. The society says the ads, the first of their kind in the country, will be about 'IVF doctors stopping people from having IVF'. It hopes to draw...
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.