While it may seem that miscarriages are rare, they are actually more common than you think. “Ten to twenty percent of all pregnancies result in miscarriage,” explains Nicole Scott, MD, gynecologist at Indiana University Health. “For women under the age of 35 the rate is about 10 percent, for women ages 35 to 40, the rate is about 20 percent and for women over 40 the rate can be as high as 50 percent.”
While many women tend to blame themselves in the aftermath of the news , Dr. Scott says a miscarriage is rarely preventable. So what causes them? Early miscarriages, those that transpire in the first trimester, are often due to abnormalities of the fetus. Up to 60 percent of first-term miscarriages are due to chromosomal abnormalities, including Down syndrome. “Basically, the egg and sperm didn’t get together quite right or there are hormonal problems like diabetes or thyroid,” says Dr. Scott. Second trimester miscarriages are often caused by anatomical problems—the shape of the uterus causes a problem or fibroids are present, for example.
If the fetus doesn’t make it into the third trimester—after 20 weeks—it’s no longer considered a miscarriage, she says, it’s considered a stillbirth. “It’s rare for this to happen, one in 1,000 chance,” notes Dr. Scott.
Reasons behind repeat miscarriages
So if you’ve already had a miscarriage are you more likely to have another? “The risk is slightly increased, but the number is still low,” says Dr. Scott. For women who have multiple miscarriages, what ob-gyns look at is if there was a live full-term birth, in addition to the miscarriages. If you’ve had miscarriages but also full-term pregnancies doctors are not as worried as someone who has never been able to carry a full-term live birth.
What should women with multiple miscarriages do? “If you’ve had two or more miscarriages, your ob-gyn will run rests to make sure everything is okay,” says Dr. Scott. This can include genetic testing and hormonal testing (like testing the thyroid). If your ob-gyn hasn’t found anything suspicious, he or she may refer you to reproductive endocrinology and infertility specialist (REI), they specialize in issues of infertility.
Should you test the embryo after a miscarriage to see what went wrong? “Generally for the first or second miscarriage this is not done,” says Dr. Scott, “but it’s advised to do this after the third miscarriage.” Doctors can run tests on the pregnancy tissue and fetus to see if there are genetic abnormalities.
Know what’s normal
While miscarriages are not uncommon, if you have hormonal issues (including thyroid) or a history of genetic problems, or have an autoimmune condition that involves blood clotting issues, you want to make sure you bring this up to your ob-gyn. Your doctor will decide if you’re considered high-risk. “If you’ve had three or more miscarriages that’s considered high-risk,” says Dr. Scott.
Trying to conceive again after a loss
While it can be frustrating for you to hear that you should try again, Dr. Scott notes that research has actually shown that trying sooner rather than later is better. “We used to tell women to wait awhile after a miscarriage to try to conceive again, but newer evidence is showing that it’s actually more successful to try again sooner rather than later. We don’t know exactly why, but it is interesting data.”
How soon should a woman try again to conceive after a miscarriage? “As soon as she feels physically and emotionally ready,” suggests Dr. Scott. The good news: The numbers are still in a woman’s favor, even after multiple miscarriages. “Even after 3 miscarriages, there’s still a 60 percent chance to have a full term successful pregnancy,” reassures Dr. Scott.