Low IVF success rates in obese women may be due to an abnormal embryo metabolism, according to new research.
The recent study undertaken by the fertility clinic, IVI, has concluded that low IVF success rates in obese women may be due to an abnormal embryo metabolism, that is different in embryos of normal weight women.
With only 30% of the world's IVF treatments being successful, this breakthrough research could provide another reason for the amount of unsuccessful cycles, and could therefore help more couples have successful IVF treatment.
The study carried out by Associate Professor Doctor José Bellver at IVI Fertility sought to determine whether the development in day three embryos is different in obese and normal weight women undergoing IVF treatment. The study also considered the impact of Polycystic Ovary Syndrome (PCOS) which can worsen obesity.
IVI Fertility Associate Professor Dr José Bellver comments:
"Our study has shown that embryos work in a different way according to the female body mass index. In a recent analysis we have identified some of these different metabolites. It seems that embryos from obese women secrete fewer quantities of saturated fatty acids to the culture media than embryos from normal weight women.
"Our findings may be related to the lower success rates of implantation and ongoing pregnancy observed in obese women. These findings open a new line of research for us."
Twenty-eight women, all aged below thirty-eight years old with normal uterus and ovaries, were put into three groups: obese non-PCOS, obese with PCOS and normal weight, and all women underwent their first IVF attempt.
To determine the differences in embryo development, researchers took samples from the secreted spent media culture of 56 day three embryos. Blood tests were also taken from the women providing an overall picture of their body's chemical balance and metabolism.
The preliminary results found the metabolites detected in the spent culture media of the day three embryos were different in normal weight and obese women. This means the embryos in obese women work differently by consuming and releasing different metabolites to and from the culture media.
The study concludes that there appears to be a difference in the embryo metabolism depending on female body mass index, perhaps related to the reduced implantation and ongoing pregnancy rates seen in obese women.
UK leading NHS weight loss surgeon & consultant Dr Sally Norton advises that even if women are trying to get pregnant the natural way, this can also be affected by obesity.
She explains: One of the many reasons that women, and occasionally men, come to see me for weight loss advice is because they want to start a family, but are struggling. Did you know that obesity is a major cause of difficulty getting pregnant - and can increase the risk of miscarriage or problems during pregnancy and childbirth? In fact, there is a significantly greater risk of diabetes during pregnancy if you are overweight - and this can affect the future health of your child as well as you.
Research evidence shows that being overweight can contribute to period problems, hormonal imbalances, lack of ovulation, resistance to fertility treatment and therefore fertility problems particularly in women with polycystic ovarian syndrome (PCOS).
There is a higher risk of miscarriage, higher risk of abnormalities of the baby as well as still birth in women who are overweight. The pregnant overweight mother is also at higher risk of diabetes, high blood pressure and difficult or complicated delivery of the baby by Caesarean or forceps.
Some women end up seeking help with IVF (in-vitro fertilization) or other forms of fertility treatment, but this isn't usually funded unless women are below a BMI of 30 or under the age of 40 - which is why I get women coming to me for weight-loss surgery. They are desperate, the clock is ticking, and they can't seem to lose weight on their own. It's sad to see, and the stress of it all doesn't help fertility in the slightest!
Interestingly it's not all about the woman's weight. In men, being obese can cause the following problems: reduced semen volume, a reduced sperm count and increased sperm DNA damage. Losing weight will improve these parameters.
So, if you are thinking of starting a family, it is a great incentive for both you and your partner to lose weight. But you have to make sure you do it in a way that is good for you. Fad dieting which will starve your body of essential nutrients which, for women, is just at the time when you and your unborn child need them most. In fact, some studies suggest that a mother's diet, even BEFORE she actually gets pregnant, can affect the health of her child. So instead of crash dieting, treat your body with the care and respect it deserves - after all, you'll be relying on your body to create a healthy new life within it. Fill it with the most nutritious food you can find, keep active to ensure you are as fit as you can be - and not only will you be rewarded with a slimmer healthier body but you will find it easier to get pregnant too.
National Fertility Awareness Week (27 October -2 November), organised by Infertility Network UK, aims to make everyone aware of the transient nature of fertility and also to get people to talk about it more openly.
Dr Thomas Mathews, UK Medical Director of Bourn Hall Clinic, says that many people do not realise how incredible it is that any of us are here at all.
"Only one in four natural conceptions results in a baby and a woman has only four fertile days a month when she releases a mature egg and can become pregnant. The effort it takes a sperm to find the egg has been compared to a blindfolded swimmer trying to find a beach ball in an Olympic-sized swimming pool!
"That said, 84% of couples will become pregnant within one year if they have regular unprotected intercourse. The best fertility advice is to reduce stress in your life and make time for sex," Dr Mathews reassures.
"However, if you have been trying for a baby for over two years and been unsuccessful then it would be advisable to seek advice. There are many non-invasive measures that can be taken to boost the chance of success, from changing your diet through to taking medication to increase ovulation," he says.
For women fertility is short-lived. Although men continue to produce sperm throughout their lives, women are born with all the eggs they will ever have. The eggs released first are those that were made first so are the best quality. Eggs released when a woman is in her mid to late thirties are of poorer quality so fertility declines quickly after 35 years, but women can continue to have children until the menopause when all the eggs are gone.
Tests such as semen analysis for men and an AMH (Anti-Mullerian Hormone) blood test for women along with a pelvic scan and an expert consultation can be used to eliminate most of the common reasons for infertility; for example, poor quality or quantity of sperm, shortage of eggs, Polycystic Ovarian Syndrome or blocked tubes.
These tests are available on the NHS to couples that meet certain criteria, but often take several years to complete. With a Bourn Hall Fertility Check these tests take place over just a few weeks and this enables individuals or couples to make informed choices about their fertility options.
Dr Mathews continues: "About 3.5 million people in the UK experience difficulties conceiving. Often simple changes to your lifestyle and diet can help improve chances of conceiving, whether naturally or through treatment.
"We also provide free independent and impartial emotional support to all our patients."
To support National Fertility Awareness Week Bourn Hall Clinic is donating £40 to Infertility Network UK for every Fertility Check booked during the week.