4 miscarriage myths and the true risk factors
She wants you to know this: While you can adopt healthy habits to improve your chances of a healthy pregnancy, the vast majority of miscarriages happen for reasons out of your control.
First: Just how common is miscarriage?
Miscarriage, a pregnancy that ends on its own before the 20th week, occurs in about 10-25 percent of confirmed pregnancies. Risk decreases with each passing week of pregnancy. By the 15th week, the risk drops to about 0.6 percent.
Dr. Bondurant-Sullivan debunks four miscarriage myths that come up in our Ob/Gyn Department:
Myth #1. Miscarriages happen because of stress or activity
Feeling stressed or exercising heavily are not likely causes of miscarriage. Instead, about half of miscarriages are due to abnormalities in fetal chromosomes, which carry genes. These abnormalities (a missing or extra chromosome, for example) are typically random and rarely the result of genetics from the parents.
Other potential miscarriage causes include:
- Abnormal uterine structure – The shape or size of the uterus can interfere with embryo implantation and growth
- Congenital anomalies – This means the fetus is developing structurally in an abnormal manner that may not be compatible with continued growth and survival
- Maternal diseases – Some infections or illnesses that can lead to miscarriage include:
- certain conditions involving the mother’s thyroid levels
- diabetes that is not well controlled
- conditions that make the mother prone to blood clots
- infections such as toxoplasmosis, which is typically caused by contact with cat feces or raw meat
- Unexplained - Often miscarriages have no clear cause.
Myth #2. I (the mother) did something to cause itMany women who experience early pregnancy loss feel guilt and blame themselves for the miscarriage, according to Dr. Bondurant-Sullivan.
“They believe that if only they wouldn’t have exercised or if only they had not had that one alcoholic drink before finding out they were pregnant, that this wouldn’t have happened,” she says.
“Overall, it is highly unlikely that a woman’s actions or lifestyle were responsible for the miscarriage.”Along with stress and exercise, eating fish and drinking minimal to moderate amounts of alcohol before recognizing pregnancy are not common miscarriage causes.
Myth #3. If you have an abortion, you are more likely to experience a miscarriageAn abortion does not affect a woman’s ability to have a normal pregnancy.
Myth #4. Miscarriages run in my familyThere are some inherited blood-clotting disorders or familial genetic abnormalities that can pass to a fetus, but this type of cause is exceedingly rare.
What are the true risk factors?
Dr. Bondurant-Sullivan says these are the most common risk factors associated with early pregnancy loss:
Increasing age of the mother
- For women aged 20-30, the miscarriage rate is about 9-17 percent.
- Starting around age 35, the rate is about 20 percent.
- For women in their early 40s, this rate increases sharply to about 40 percent.
- For women over 45, the rate is about 80 percent.
After a single miscarriage, the rate for second pregnancy loss does not increase significantly. However, after two miscarriages, the rate goes up to 28 percent and up to 43 percent after three or more consecutive miscarriages.