Miscarriage, which is the spontaneous loss of a pregnancy before 20 weeks, is one of those life events that tends to be so profoundly sad and confusing for people to make sense of that it becomes hush-hush. And that, in turn, often leads to a sense of deep isolation for women and couples struggling to come to terms with pregnancy loss -- despite the fact that it is extremely common. Here's just how common it is, as well as other startling miscarriage facts everyone should know:
1 million miscarriages occur in the United States every year, according to our best estimates. Though it's hard to pinpoint an exact figure, groups like the American College of Obstetricians and the Mayo Clinic generally say between 15 and 20 percent of known pregnancies end in miscarriage. Mayo emphasizes, however, that the actual number is probably much higher, because many occur before a woman even misses her period and realizes that she is pregnant. (The March of Dimes says that if you take into account those instances, it's more like 50 percent of all pregnancies that end in miscarriage.)
55 percent of adults think that miscarriage is uncommon. In a startling survey of 1,000 adults -- more than half of whom were women and 15 percent of whom had themselves experienced a miscarriage -- just over half of the respondents said they believed miscarriages happen in less than 6 percent of pregnancies, which, of course, is a significant under-estimation of how common they are.
76 percent of adults think stress is a common cause of miscarriage. Wrong again. There is little evidence supporting a potential link between stress and miscarriage. And we as a public tend to get the other causes wrong as well: The same survey looking at perceptions of miscarriage found that 64 percent of respondents believed lifting something heavy could cause a pregnancy to end, while 22 percent said oral contraceptives lead to miscarriage -- neither of which are true. Perhaps most unsettling? Twenty-three percent believed miscarriage could occur simply as a result of a woman not wanting the pregnancy. The truth is that most miscarriages -- upwards of 60 percent, according to ACOG -- occur because of chromosomal abnormalities that are completely out of a couple's control.
1/3 of pregnancies among women age 40 and older end in miscarriage, ACOG estimates. Again, the majority of miscarriages are caused by chromosomal problems within the embryo, which occur when it receives either too many or too few chromosomes (an embryo with an abnormal number of chromosomes cannot survive). The likelihood of chromosomal abnormalities increases as women get older, ACOG states, though why exactly isn't fully understood. "The rate of chromosomal abnormality appears to be hard-wired into our species," a chromosome biologist once told NPR. "The only thing that moves the dial is maternal age."
1 percent of women have repeat miscarriages. A woman is considered to have what is known as "recurrent pregnancy loss" if she has had two or more miscarriages, -- and after three, it is recommended that she seek out testing for possible causes. Unfortunately, ACOG estimates that in 50 to 75 percent of women with recurrent pregnancy loss, doctors are unable to find a clear cause. However, ACOG also states that 65 percent of women with unexplained repeated miscarriages do go on to have a successful next pregnancy.
40 percent of women who have had miscarriages say that after, they felt very alone. In a poignant essay for The New York Times, writer Kendra Hurley -- who has herself experienced recurrent pregnancy loss -- described the feeling, explaining that "miscarriage, like early pregnancy, is still a largely private affair."
"This quietness in the face of something that feels, to some women, so physically and emotionally overwhelming can be confusing," she said. "It can make it all feel shameful."
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