Miscarriage Causes: Immune Mechanisms

The fetus contains foreign genetic material coming from the father, but in normal circumstances it does not get rejected. However, in some women the immune system may reject the fetus and cause a miscarriage either by being high in numbers or by abnormal hostile activity. There are several immune disorders:-

Antiphospholipid Antibodies

What are Antiphospholipid Antibodies?

Antiphospholipid syndrome (APS) predominantly affects young women and there has been a growing awareness of this condition amongst obstetricians and gynaecologists over the last few years.

Pregnancy makes the blood stickier and women with APS are at increased risk of blood clots unless blood-thinning medication is adequate.

APS is associated with both early and late pregnancy morbidity and loss. Pregnancy loss can be a miscarriage, intrauterine death, stillbirth or neonatal death.

Early pregnancy failure may result from impaired development of the placenta.


It is essential that women with APS who are considering embarking on a pregnancy are aware of the risks involved so that they can make an informed decision about conception whenever possible.

I will offer you to start low dose Aspirin pre-pregnancy. I may need to add Heparin when you achieve a pregnancy and therefore you should present yourself as soon as you discover yourself pregnant, so that the Heparin can be started promptly.

Safety of drugs and possible side effects

Heparin: it is a large molecule and therefore does not cross the placenta and is harmless to the fetus. It is a daily injection which may cause slight bruising, but otherwise safe to the mother. Rarely, as with any other drug you may develop a drug allergy, which may lead to change of brand.

Aspirin: is safe for the fetus. If you have asthma or a stomach ulcer you need to inform me prior to commencement of the programme.