True Miscarriage Rates

Making Sense of Pregnancy Loss Statistics

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Miscarriage rates can be confusing, especially if you're looking for answers while dealing with a pregnancy loss.

It's easy to become overwhelmed by the many statistics floating around. Depending on the context, you might find miscarriage rates ranging from 5 to 70 percent.

What's even more confusing is that most of these numbers are correct when put into context.

For example, one study found that women who have given birth have a 5 percent risk of miscarrying the next time around.

Other research has indicated that 70 percent of fertilized eggs may never go on to become a full-term pregnancy.

But those numbers don't help you if you're just trying to determine an average person's risk of miscarriage.

Among women who know they are pregnant, the average risk of miscarrying before 20 weeks is somewhere between 8 and 20 percent. 

However, if you find out you're pregnant very early - such as with an early pregnancy test before you miss your period - your overall risk might be higher, around 30 percent. But this is only because you may detect a very early miscarriage that would have otherwise gone unnoticed, not because you're more likely to have a miscarriage. 

The rates of miscarriage are highest in the first trimester​ - 80 percent of miscarriages happen in the first 12 weeks. If your pregnancy has already progressed beyond the first trimester, the greatest risk of miscarriage has most likely passed.

Miscarriage Statistics - Beyond the Basics

Remember that statistics on miscarriage rates are just that - statistics. Your true risk of miscarriage may be higher or lower than average depending on whether or not you have risk factors.

For example, women over 35 have higher miscarriage rates than women in their 20s.

And women who have successfully given birth in the past have lower pregnancy loss rates than women in their first pregnancies. And so on.

Here are some other questions you might have about miscarriage rates:

What if I had a miscarriage last time? Most first-time miscarriages are random and do not reoccur. With one past miscarriage, the odds of miscarrying in your next pregnancy are about 20 percent. This is not much higher than someone without a history of miscarriage. With two previous miscarriages, the risk of another miscarriage is 28 percent, and with three previous miscarriages the risk increases to 43 percent. It's possible that having testing for recurrent miscarriage causes might help in these cases.

What if I've seen the heartbeat on an ultrasound? Most research suggests that the odds of miscarrying decrease once the pregnancy has reached the point that an ultrasound can detect a heartbeat. At this point, estimates for miscarriage rates range from 2 to 5 percent.

Can I do anything to reduce my risk of miscarrying? 

There's not a whole lot you can do to affect your odds of miscarriage, but research suggests you may have a lower risk of miscarriage if you avoid alcohol, don't smoke and avoid known occupational hazards.

Source:

Patient information: Miscarriage (Beyond the Basics). UpToDate. July 16. 2015.

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