Placenta 'fools body's defences'

The placenta supplies the foetus with essential nutrients

The placenta acts like a parasite to avoid attack by a mother's immune system, researchers have discovered.
A University of Reading team found it employs a cloaking device very similar to that used by parasitic worms.

They hope the finding will aid a greater understanding of recurrent miscarriages, and the potentially dangerous condition pre-eclampsia.

Mimicking this method of avoiding immune rejection may also provide ways to tackle conditions like arthritis.

The placenta plays a vital role in pregnancy, acting as a link between the mother and foetus and providing it with essential nutrients.

However, as both the placenta and foetus have a different genetic make-up from the mother, in theory they are at risk of attack from her immune system.

The researchers already knew that the placenta secreted a small protein - neurokinin B (NKB) - which is found in significantly higher levels in mothers when pre-eclampsia develops.

NKB can be detected as early as week nine of pregnancy, and so can be used to spot women who are at risk.