A missed miscarriage occurs in roughly 2 to 3% of all pregnancies when measured by ultrasound in the first trimester. In a large screening study of nearly 18,000 women scanned between 10 and 13 weeks, 2.8% had an early pregnancy failure, and about 63% of those cases were specifically missed miscarriages (where the embryo stops developing but the body hasn’t recognized the loss yet). That puts the overall rate of missed miscarriage at roughly 1.7% of all pregnancies scanned during that window.
If you’re reading this, you may be worried about an upcoming scan or trying to make sense of a diagnosis you’ve already received. Here’s what the numbers actually look like, what causes this type of loss, and what happens next.
How Common Missed Miscarriage Is by Week
The overall risk of any miscarriage drops sharply as pregnancy progresses. At 6 completed weeks of gestation, the risk for asymptomatic women who’ve had a normal prenatal visit is about 9.4%. By 7 weeks it falls to 4.2%, by 8 weeks to 1.5%, and by 9 weeks to just 0.5%. Once you’ve reached 8 weeks with a confirmed heartbeat and no symptoms, the odds of continuing past 20 weeks are very good.
What makes a missed miscarriage different from other types is timing. The pregnancy stops developing, but the physical process of miscarriage (bleeding, cramping, tissue passage) doesn’t start right away. It can take weeks. In one study, nearly half the women who experienced a missed miscarriage didn’t receive their ultrasound diagnosis until the second trimester, even though the pregnancy had likely stopped growing much earlier. This is why many missed miscarriages are first discovered at a routine scan rather than prompted by symptoms.
Why It Happens Without Symptoms
The hallmark of a missed miscarriage is that you often still feel pregnant. Nausea, breast tenderness, and fatigue can all continue because pregnancy hormones take time to decline after the embryo stops developing. In some cases, this delay lasts weeks. There’s no reliable physical sign that distinguishes a missed miscarriage from an ongoing pregnancy without an ultrasound.
Some women notice a subtle fading of pregnancy symptoms, but many don’t. That uncertainty is part of what makes this type of loss so disorienting. You may walk into a routine appointment expecting to see a heartbeat and learn instead that the pregnancy stopped developing days or weeks earlier.
What Causes a Missed Miscarriage
About half of all first-trimester miscarriages are caused by chromosomal abnormalities in the embryo. These are random errors that occur when the egg and sperm combine, resulting in too many or too few chromosomes for the pregnancy to continue. Numerical chromosome errors (having an extra or missing chromosome) account for about 86% of the chromosomally abnormal miscarriages. In a study of 198 first-trimester miscarriage samples, an abnormal chromosome result was found in 42% of cases.
These errors are not caused by anything the mother did or didn’t do. They’re a biological reality of early human reproduction, which has a relatively high rate of chromosomal mistakes compared to other species. Other less common causes include blood clotting disorders, hormonal imbalances, and structural differences in the uterus, but for most women who experience a single missed miscarriage, the cause is a one-time chromosomal problem that is unlikely to repeat.
How It’s Diagnosed
A missed miscarriage is confirmed by ultrasound. The key finding is either an embryo without a heartbeat or a gestational sac that contains no embryo at all (called an anembryonic pregnancy, or “blighted ovum”). In the large screening study mentioned earlier, about 63% of early pregnancy failures were missed miscarriages with a visible embryo, and 37.5% were anembryonic pregnancies.
Hormone levels can provide clues before ultrasound. In a healthy pregnancy, hCG (the hormone detected by pregnancy tests) rises by at least 53% over two days. In pregnancies headed toward loss, hCG levels tend to rise more slowly, plateau, or decline. However, a single hCG reading can’t confirm a missed miscarriage on its own. Slow-rising levels prompt further monitoring, and the definitive answer comes from ultrasound.
What Happens After Diagnosis
Once a missed miscarriage is confirmed, there are three paths forward: waiting for your body to complete the process naturally, using medication to help it along, or having a minor surgical procedure.
Waiting It Out
Expectant management means letting your body recognize and complete the miscarriage on its own. Given enough time (up to 8 weeks), this approach works in about 80% of women. The success rate tends to be higher for women who have already started passing tissue or bleeding compared to those with no symptoms at all. For missed miscarriages specifically, the process can take longer to begin than for other types of pregnancy loss, and the wait can be emotionally difficult.
Medication
A vaginal medication can be used to help the uterus begin contracting and expelling tissue. With a single dose, the success rate is somewhat lower, but with a second dose if needed, it reaches about 84%. You’ll typically have a follow-up ultrasound within 7 to 14 days to confirm the process is complete. Most women experience cramping and heavy bleeding, similar to a heavy period, within several hours of taking the medication.
Surgical Procedure
A D&C (dilation and curettage) is a brief procedure, usually done under sedation, that removes pregnancy tissue from the uterus. It’s the fastest and most predictable option. Risks are low but include a small chance of uterine perforation, infection, or bleeding. In rare cases, scar tissue can form inside the uterus afterward (Asherman’s syndrome), which can affect future periods and fertility. This is uncommon and treatable with a follow-up procedure if it occurs.
Chances of It Happening Again
After one miscarriage of any type, the risk of miscarriage in your next pregnancy is about 20%. That number sounds high until you consider that the baseline miscarriage rate for all pregnancies is around 10 to 15%. So while the risk does increase slightly, 80% of women who’ve had a single miscarriage go on to have a successful subsequent pregnancy.
Most women can try conceiving again after one normal menstrual cycle, though the emotional timeline varies. A single missed miscarriage does not typically prompt additional testing or a workup for recurrent loss. Investigations into underlying causes generally begin after two or three consecutive losses.