Miscarriages are much more common than most people realise. Among women who know they're pregnant, it's estimated about 1 in 8 pregnancies will end in miscarriage. Many more miscarriages happen before a woman is even aware she has become pregnant.

How common is it to miscarry a baby?

As many as 50% of all pregnancies end in miscarriage -- most often before a woman misses a menstrual period or even knows they're pregnant. About 15%-25% of recognized pregnancies will end in a miscarriage. More than 80% of miscarriages happen within the first 3 months of pregnancy.

When is the most common week to miscarry?

The first trimester is associated with the highest risk for miscarriage. Most miscarriages occur in the first trimester before the 12th week of pregnancy. A miscarriage in the second trimester (between 13 and 19 weeks) happens in 1% to 5% of pregnancies.