A missed abortion, more commonly called a missed miscarriage, is a type of pregnancy loss where the embryo or fetus has died but remains in the uterus instead of being expelled naturally. Unlike other forms of miscarriage that involve noticeable bleeding and cramping, a missed miscarriage often produces no obvious symptoms at first. Many people only learn about it during a routine ultrasound, when no heartbeat is detected.
The term “abortion” in this context is a clinical one. It doesn’t refer to an elective procedure. In medical terminology, “abortion” simply means the end of a pregnancy before viability, whether spontaneous or intentional. A missed abortion is always spontaneous.
Why It’s Called “Missed”
The word “missed” refers to the fact that your body hasn’t yet recognized the loss. Normally when a pregnancy ends, the uterus contracts to expel the tissue, causing bleeding and cramping. In a missed miscarriage, those signals don’t fire. The placenta may continue producing enough hormones to maintain pregnancy symptoms like nausea, breast tenderness, and fatigue, even though the embryo has stopped developing. This can go on for days or weeks before anything changes.
That hormonal delay is what makes this type of loss particularly disorienting. A home pregnancy test will still read positive. You may feel pregnant. The diagnosis typically comes as a surprise during an ultrasound that shows a gestational sac with no fetal heartbeat.
How It’s Diagnosed
A missed miscarriage is diagnosed by transvaginal ultrasound. The key finding is an embryo with no cardiac activity. Current guidelines define a missed miscarriage when the embryo measures more than 7 mm in length (crown to rump) and has no detectable heartbeat. In some cases, the ultrasound shows a gestational sac with no visible embryo at all, sometimes called a blighted ovum.
If there’s any uncertainty, your provider will typically repeat the ultrasound a week or so later to confirm the diagnosis before recommending any treatment. This waiting period exists to avoid misdiagnosing a very early but viable pregnancy.
What Causes a Missed Miscarriage
Chromosomal abnormalities in the embryo are the primary cause. Research on tissue samples from missed miscarriages has found chromosomal problems in roughly two-thirds of cases, with trisomy 16 and Turner syndrome being the most common. These are random errors in cell division that happen during fertilization or early development. They aren’t caused by anything the mother did or didn’t do.
The remaining cases involve a mix of factors: hormonal imbalances, immune system responses, uterine structural issues, or problems with blood flow to the developing pregnancy. In many individual cases, no specific cause is ever identified. Most missed miscarriages occur in the first trimester, within the first 13 weeks of pregnancy.
Three Treatment Options
Once a missed miscarriage is confirmed, there are three paths forward. You and your provider will choose based on how far along the pregnancy was, your health, and your personal preference.
Expectant Management (Waiting)
This means allowing your body to complete the miscarriage on its own, without intervention. Success rates vary depending on the situation. For a missed miscarriage specifically, about 59% of cases resolve within two weeks and 76% within six weeks. The tradeoff is unpredictability: you won’t know exactly when the bleeding and cramping will start, and there’s a meaningful chance you’ll ultimately need medication or a procedure if the tissue doesn’t pass completely.
Medication
A medication called misoprostol helps the uterus contract and expel the pregnancy tissue. For missed miscarriages, it produces a complete result in about 88% of cases. Most people experience heavy cramping and bleeding within 24 hours of taking the medication. A follow-up visit within one to two weeks confirms that everything has passed. If it hasn’t, a second dose or a surgical procedure may be needed.
Surgical Procedure
A procedure called curettage (sometimes referred to as a D&C) removes the tissue directly. It has the highest success rate at 97 to 98% and is the most predictable option in terms of timing. It’s typically done under sedation and takes about 15 to 20 minutes. This option is sometimes recommended when there are concerns about heavy bleeding or incomplete tissue passage.
Across all three options, a small percentage of cases (5 to 20%) ultimately require curettage to fully complete the process.
Physical Recovery
Regardless of which treatment path you take, uterine cramping may last several days and vaginal bleeding can continue for up to three weeks. The intensity varies. Most people describe the first few days as the hardest physically, with symptoms gradually tapering off.
Your menstrual cycle will typically return within four to six weeks after the miscarriage is complete. That first period may be heavier or lighter than usual. Ovulation can resume before that first period arrives, which means pregnancy is technically possible even before your cycle fully resets.
Future Pregnancy After a Missed Miscarriage
The odds of a healthy future pregnancy are strongly in your favor. A large study of women with a history of one or two pregnancy losses found that those who started trying again within three months had higher live birth rates (53%) compared to those who waited longer than three months (36%). The researchers found no increased risk of complications for couples who conceived sooner.
The traditional advice to wait three to six months before trying again appears to lack physiological support. Women in the study who waited longer than 12 months actually had lower fertility rates, even after accounting for other factors. The current evidence suggests that once you feel physically and emotionally ready, there’s no medical reason to delay. A single missed miscarriage does not indicate a fertility problem. It’s an unfortunately common event that affects a significant percentage of all recognized pregnancies.