Blood live free sex chart

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.

There are four main blood groups — A, B, O, AB — and several subgroups for each (O, for instance, can be Rh D ­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.

There are theories it might affect anything from dental health to ­cancer. Early studies suggested type A blood groups ­suffered worse hangovers and type O meant better teeth.

This tests how many ‘resting’ ­follicles there are in the ovaries.

‘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 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.