A miscarriage is the loss of a baby before 24 weeks of gestation. If the loss occurs during the first 12 weeks of pregnancy, it is called an early miscarriage. If the loss happens after the twelfth week, it is called a late miscarriage. Unfortunately, early miscarriages are all too common. Very often, a woman will miscarry before she even realises she is pregnant. Possibly as many as three-quarters of all fertilised eggs are lost in the earliest days of pregnancy. There's about a one in five chance of having an early miscarriage after a positive pregnancy test.
Late miscarriages are much less common, and happen in about one in 100 pregnancies. Late pregnancy loss can be very difficult to accept. At this stage, the term "miscarriage" doesn't do justice to the depth of grief they feel at losing their much anticipated baby. There are some unfortunate women, about one woman in 100, who experience the anguish of recurrent miscarriage. This means that they have had three or more miscarriages in a row.
It's tough to say who's at risk. Frequently the lost pregnancy happens for no apparent reason and there is nothing that could have been done to prevent it. This is especially true with early miscarriage. The reality is that many women who have miscarriages are perfectly healthy.

We do know of some factors that may increase the chances of miscarriage:
  • Your age – The older you are when you conceive, the more likely it is that developing baby will have a chromosomal abnormality. Your risk of miscarriage is one in five at 30 years. At 42 years of age, your risk is one in two. 
  • Your health - If you are overweight, have a poorly controlled medical condition, such as diabetes or have a thyroid problem, can increase the chances of miscarriage. So if you have any problems with your health, get the right care, now.
  • Antiphospholipid syndrome (APS) or sticky blood syndrome, causes blood clots to form in blood vessels, and is known to cause recurrent miscarriage. APS, is also known as Hughes syndrome, can be a problem all on its own or can happen in conjunction with lupus. APS is treatable. Miscarriage is more likely in women that have abnormalities of the uterus.
  • Infections during pregnancy can cause miscarriage such as listeriosis and toxoplasmosis. Conditions that affect your hormones such as poly-cystic ovaries, and sexually transmitted infections, such as syphilis are also associated with late pregnancy loss.
  • Your lifestyle – Smoking, heavy alcohol consumption and the use of cocaine all place you at high risk for miscarriage. Also having too much caffeine in your diet may also increase your risk. You can safely drink two mugs or consume up to 200 mcg of coffee a day.