Between 10 and 20 percent of known pregnancies end in miscarriage, making it far more common than most people realize. When you include losses that happen before a person knows they’re pregnant, the number climbs higher: some estimates put the total rate above 30 percent of all conceptions. If you’re pregnant or trying to conceive and wondering about your personal risk, the answer depends heavily on how far along you are, your age, and a few other factors.
How Risk Changes Week by Week
The risk of miscarriage is highest in the earliest weeks, then drops sharply. Most losses happen before the 12-week mark, and the vast majority of those occur before you’d even see a heartbeat on ultrasound. Many very early losses, sometimes called chemical pregnancies, happen before a period is even missed. About 25 percent of all pregnancies end within the first 20 weeks, and roughly 80 percent of those losses happen in the earliest stages.
Once a pregnancy is far enough along to be confirmed on ultrasound, the numbers become more reassuring. At 6 weeks, the risk of miscarriage is around 9.4 percent. By 7 weeks, it drops to about 4.2 percent. At 8 weeks, it falls to just 1.5 percent and continues to decline from there. Between weeks 14 and 19, the estimated risk is between 1 and 5 percent. So each week that passes without problems meaningfully lowers your chances of a loss.
Maternal Age Is the Biggest Factor
Age has a larger effect on miscarriage risk than almost anything else. For women under 35, the miscarriage rate after an ultrasound-confirmed pregnancy is under 15 percent. At 40, that rises to about 29 percent. By 44, the risk reaches roughly 60 percent, and it continues to climb after that.
This increase is driven largely by the quality of eggs, which naturally accumulate more genetic errors over time. The result is a higher rate of chromosomal problems in the embryo, which is the single most common reason pregnancies fail. Chromosomal abnormalities are found in about 67 percent of miscarried pregnancies. These are random errors in cell division that happen at or shortly after conception, and they aren’t caused by anything the mother did or didn’t do.
Paternal Age Matters Too
Most conversations about miscarriage focus on the pregnant person, but the father’s age plays a role as well. A study published in Fertility and Sterility found that when the father was 50 or older, the odds of a first-trimester miscarriage were about three times higher compared to fathers aged 25 to 29, even after accounting for the mother’s age. This likely reflects an increase in sperm DNA damage that comes with aging.
Caffeine, Smoking, and Other Lifestyle Factors
A National Institutes of Health study found that couples who both drank more than two caffeinated beverages per day in the weeks leading up to conception had a significantly higher risk of miscarriage. The increased risk was similar for both partners: about 73 to 74 percent higher compared to couples who consumed less. Women who continued drinking more than two caffeinated beverages daily through the first seven weeks of pregnancy also had elevated risk.
Smoking and heavy alcohol use are also linked to higher miscarriage rates, though pinning down exact thresholds is harder. What is clear is that these exposures matter most in the weeks around conception and during the first trimester, when the embryo is most vulnerable to disruption.
Your Risk After a Previous Miscarriage
Having one miscarriage does not mean you’re likely to have another. After a single miscarriage, the risk of it happening again is about 20 percent, which is only slightly above the baseline rate for any pregnancy. After two consecutive losses, the risk rises to about 25 percent. After three or more in a row, it reaches 30 to 40 percent.
Even at the high end, those numbers mean the majority of people who experience recurrent miscarriage still go on to have a successful pregnancy. Recurrent loss (typically defined as three or more consecutive miscarriages) does warrant medical evaluation, since treatable causes like hormonal imbalances, uterine abnormalities, or blood clotting disorders can sometimes be identified.
Why Most Miscarriages Happen
The overwhelming majority of miscarriages are caused by chromosomal abnormalities in the embryo. These are essentially random errors: an extra chromosome, a missing one, or a structural rearrangement that prevents normal development. The embryo stops growing, and the pregnancy ends. This is not something that can be prevented through behavior changes or medical intervention.
A smaller share of miscarriages are linked to other causes. Structural issues with the uterus, problems with the cervix, infections, uncontrolled conditions like diabetes or thyroid disease, and immune system factors can all contribute. These are more common in second-trimester losses and in cases of recurrent miscarriage, where they’re more likely to be investigated and, in many cases, treated.
What Happens if You Have One
Most early miscarriages resolve on their own without medical intervention. Current clinical guidelines recommend a watch-and-wait approach as the first option for an incomplete early loss, as long as there’s no excessive bleeding or signs of infection. This approach is successful more than 90 percent of the time. If the process stalls or if you prefer not to wait, medication or a brief procedure can help complete the process.
Physically, recovery from an early miscarriage typically takes a few days to a couple of weeks. A normal menstrual cycle usually returns within four to six weeks. Most people can try to conceive again after one normal period, though the emotional timeline varies widely and is just as important to honor.