What Blood Type Can Make It Hard to Have a Baby

Yes blood group O does affect your chances of having a baby

More women than ever are now undergoing IVF treatment - the number has risen more than ­tenfold since the early Nineties.

It's a statistic which is often blamed on the growing trend for postponing ­motherhood until later in life.

But now it seems a woman's chances of conceiving in her 30s or 40s may not be decided by age alone - her blood type could also affect her fertility, a­ccording to research published ­yesterday in the Mail.

A woman's blood group appears to influence the amount of a ­hormone called follicle-stimulating hormone (FSH) that she produces

In particular, women with blood type O - the most common type - had a lower egg count and poorer egg quality in their 30s than those with blood type A, say researchers at the Albert Einstein ­College of Medicine in New York.

But how significant are the findings and what are the implications for women planning to start a family in their 30s or later?

We asked the experts...

Why do we have different blood types?

There are four main blood groups — A, B, O, AB — and several subgroups for each (O, for instance, can be RhD ­positive or negative) and the one you have depends on your genetic make-up.

If both your parents were type O, then you will be O; however, after that there are no hard and fast rules. For example, both your parents could be type A, but you could still end up with type O.

Around 44 per cent of people in Britain have blood group O. Type A accounts for 42 per cent and the balance is made up of less common blood types, including type B and type AB.

The ­difference between the blood types is determined by the kind of ­proteins found on the surface of red blood cells — if you have A type ­proteins, you are classed as group A.

How is fertility linked to blood?

A woman's blood group appears to influence the amount of a ­hormone called follicle-stimulating hormone (FSH) that she produces. A follicle is a small round cavity — the egg grows in the middle of this.

During ovulation, follicles ­containing maturing eggs push towards the surface of the ovary. There, the ­follicle opens up to allow the egg to drift out. This hormone is released by the pituitary gland, a pea-sized gland in the brain.

Although it plays a vital role in pregnancy — stimulating the ­follicles so they release the eggs — studies show very high levels are a sign of infertility. In particular, they are the sign of something called a low ovarian reserve.

The ovarian reserve is a measure of how many eggs a woman is thought to have left at any one time. It can vary from one woman to another and can be depleted by smoking, ovarian cysts and ­endometriosis, a painful ­condition affecting around two million women in Britain where the cells in the­ ­lining of the womb break down.

Women are born with their entire egg reserve — about two million eggs — and they do not produce more. This number drops ­throughout life, but the decline speeds up ­rapidly after the age of 37 and by the time a woman hits the menopause, only around 10,000 eggs are left. It might sound a lot, but these eggs are poor quality.

FSH is measured in units per litre of blood. A reading of more than ten ­suggests a woman may have ­trouble conceiving. In the new study, women in their mid-30s struggling to ­conceive were twice as likely to have raised levels of FSH if they had blood type O compared with type A.

Moreover, some experts think blood type affects the immune ­system's ­reaction to attempted conception.

It has been known for some time among IVF specialists that the immune system can play a vital role in determining the success of egg implantation, explains Dr Mohamed Menabawey, from the Bridge ­Centre, a fertility clinic in London.

'Women with type O blood are the least likely to have successful IVF treatment,' he says. 'This is because they often ­experience an inappropriate immune response.'
During conception, the mother's defences need to mount what's called an 'appropriate' immune response.

This is where the immune system learns to tolerate the 'foreign' ­material from the father without launching an all-out attack that destroys it. It's thought that type O blood somehow disrupts this finely tuned reaction.

Does being group O explain why I can't conceive again?

Experts think it is unlikely. If ­having type O blood really does reduce your fertility, then this should apply irrespective of your age.

'If your chances of conceiving really do depend on your blood group, then I would have thought a woman would have difficulty whether it was her first or second child,' says Dr Joyce Harper, expert in human genetics and embryology at University College London.

'If that's the case, it should affect all pregnancies.'

Are there other ways to test how many eggs I have?

Some experts think measuring ­follicle-stimulating hormone is a rather blunt tool for determining how many eggs a woman has left.

'It's a starting point, but no more than that,' says Dr Harper. 'As a woman gets nearer to the ­menopause, FSH levels actually go up, even though the number of eggs is declining.'

More sophisticated measures include ultrasound to check the 'antral follicle' count — these are ­follicles which are dormant, but which contain a rich supply of eggs. This tests how many 'resting' ­follicles there are in the ovaries.

Blood tests look at levels of a ­hormone called anti-­Mullerian ­hormone. This is ­produced by ­immature eggs in the ovaries and is considered by some fertility ­clinics to be a better indicator of ovarian reserve.

So how do I find out my blood group?

One of the best ways is to become a blood donor. Your blood is ­automatically checked before you donate, so that experts can ensure your blood group is matched with patients who need it.

Pregnant women or those ­awaiting surgery are routinely tested for blood types. Visit blood.co.uk for information.

What can I do to boost my fertility?

Obviously you cannot change your blood type. But until further research is carried out to prove this really can determine your chances of getting pregnant, there are ­simple steps you can take.

Stopping smoking is the most important lifestyle factor. But being overweight and drinking excessively are thought to reduce fertility.

What else is linked to blood group?

There are theories it might affect anything from dental health to ­cancer. Research in this area began nearly 100 years ago. Early studies suggested type A blood groups ­suffered worse hangovers and type O meant better teeth.

But more serious studies have suggested type A increases the risk of breast, liver or pancreatic cancer — possibly because cancer cells are less visible to the immune system in patients with type A.

Other research shows men with type A may be 20 per cent more at risk of heart disease than other groups, possibly due to greater susceptibility to raised cholesterol, while type O may mean you are less likely to suffer from hay fever or other allergies.

Blood group may also affect how you respond to dangerous bugs such as E. coli — people with type B are unable to produce ­antibodies to certain strains, increasing the risk of serious illness.

What Blood Type Can Make It Hard to Have a Baby

Source: https://www.dailymail.co.uk/health/article-1323793/How-blood-group-affects-chances-baby.html

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