What is a Missed Miscarriage?

A miscarriage is pregnancy loss that occurs in the first 20 weeks of gestation, usually in the first trimester. The term missed miscarriage refers to a situation in which a pregnancy is no longer viable, but no clear miscarriage symptoms, such as vaginal bleeding, cramping in the abdomen or lower back, and the passing of tissue through the vagina are present.

How Is a Missed Miscarriage Diagnosed?

A doctor usually discovers that a missed miscarriage has occurred during a routine prenatal checkup. The diagnosis can be made based on the findings of a few different exams. 

One common blood test given during early pregnancy checks the level of human chorionic gonadotropin (hCG), a hormone that is produced by the body during pregnancy. During the first few weeks of pregnancy, the body's hCG level is expected to double every two to three days, signaling a normally developing pregnancy.

If the hCG level isn't rising quickly during early pregnancy or stops rising altogether, it could be cause for concern. Having two consecutive blood tests in early pregnancy that show a decreasing hCG level is often a strong indicator of miscarriage. 

Another clue that a missed miscarriage may have occurred is when the fetal heartbeat is not audible on a fetal heart rate monitor or handheld doppler by 12 weeks of gestation. An ultrasound (also known as a sonogram) which reveals that a baby's heartbeat has stopped can then determine that a miscarriage has in fact occurred.

What Happens After a Missed Miscarriage Diagnosis?

After a missed miscarriage diagnosis, a decision must be made of whether or not to seek medical intervention for the miscarriage. If bleeding has not yet started, a natural miscarriage, (also known as a miscarriage without intervention) might take days or weeks to begin. Symptoms of a natural miscarriage include abdominal cramping, vaginal bleeding, nausea, and vomiting.

A missed miscarriage diagnosis may require a surgical procedure called a dilation and curettage (D&C) to complete the miscarriage process. In the first trimester, it's usually called a dilation and aspiration (D&A), because the doctor dilates the cervix and then uses a tool called a suction curette (as opposed to a sharp curette) to gently empty the uterus.

Additionally, a medication called misoprostol can also be used as an alternative to a D&C as part of the medical management of a miscarriage. The medication causes the cervix to dilate and the uterine lining to be shed. Similar to a natural miscarriage, bleeding may last one to two weeks.

Why Do Missed Miscarriages Occur?

In the first trimester, one common cause of a missed miscarriage is a chromosomal abnormality in the developing fetus. These chromosomal abnormalities are random in nature, and it is typically not possible to determine if chromosomal abnormalities are present prior to a missed miscarriage.

Some missed miscarriages are due to a condition called blighted ovum. In a blighted ovum, the gestational sac and placenta continue to develop but the baby does not. With a blighted ovum, you might continue to experience pregnancy symptoms like nausea, breast tenderness, or tiredness, but a fetal heartbeat never becomes audible on a heart rate monitor, and an ultrasound will ultimately reveal an empty gestational sac.

If you've had more than one miscarriage, it is worth talking to your doctor about underlying conditions that can cause multiple pregnancy losses. When recurrent miscarriages occur, testing may help you figure out the underlying problem (if there is one). Underlying problems can include anatomical abnormalities, blood clotting disorders, and hormonal imbalances.

A Word From Verywell

A miscarriage can be a disheartening experience, but it is not always an indication of any underlying problems or an inability to get pregnant. Many people who experience miscarriages still go on to have healthy pregnancies afterward. Your doctor should be able to provide guidance if you wish to get pregnant again following a miscarriage.