Missed Miscarriage: Causes, Symptoms, Diagnosis, and Treatment

A missed miscarriage happens when the pregnancy stops developing before the 20th week of pregnancy. Also known as a silent miscarriage, a missed miscarriage typically happens without many symptoms. Your body may still feel pregnant, and you may still experience pregnancy symptoms.

The most common time for a missed miscarriage is during the first trimester (the first 12 weeks of pregnancy). It is typically diagnosed when there is no fetal cardiac activity during a routine prenatal ultrasound.

Several treatment options exist, including waiting for a miscarriage to happen on its own, taking medication to expel the fetus, and, in some cases, undergoing a procedure known as dilation and curettage. Most of the time, there is no known cause and nothing you could have done to prevent the miscarriage from happening.

Missed Miscarriage Causes

A missed miscarriage occurs when a fetus has stopped growing. There are several potential causes for a missed miscarriage. Potential causes include:

• Genetic condition of the fetus (chromosomal abnormalities are more common with advanced age)
• Structural problem with the uterus or cervix
• An underlying health condition of the pregnant individual (e.g., infection, blood-clotting disorder, or hormonal condition)
• Molar or partial molar pregnancy

A molar pregnancy is abnormal cell growth in the fertilized egg or placental tissue. In either instance, the pregnancy typically ends early in a miscarriage. In some cases, an individual may experience few or no symptoms. Several complications can result from a molar or partial molar pregnancy, and this condition will need to be managed differently from other conditions that cause a miscarriage.

Around 10% of known pregnancies will end in miscarriage. And in up to 50% of miscarriages, chromosomal or genetic abnormalities of the fetus are the cause.

The percentage of pregnancies that result in miscarriage increases with age. For example, an individual who is 40 years old has a 40% risk of their pregnancy ending in a miscarriage.

What Are the Signs of a Missed Miscarriage?

In a missed miscarriage, you may not experience any signs and continue to feel pregnant. A miscarriage usually begins with pain similar to menstrual cramps and vaginal bleeding, but a missed miscarriage usually does not cause these symptoms.

Sometimes, a person might have some cramping and brownish-pink or red vaginal discharge. These symptoms are usually mild, and since they are also things that can occur during a normally developing pregnancy, they might not be a clear indication that something isn't right.

In most cases, there are no signs that anything is wrong. Since the majority of missed miscarriages happen early on, there are no signs such as reduced fetal movement.

Additionally, even though a silent miscarriage has occurred, pregnancy hormones are still high. This means a person may continue to experience pregnancy symptoms such as breast tenderness, nausea, and fatigue, though possibly to a lesser extent than before.

A pregnancy test may continue to show a positive result as well.

Diagnosis

A missed miscarriage is often diagnosed during a prenatal care visit. An ultrasound may show the fetus is too small for gestational age and that it has undetectable cardiac activity (no heartbeat).

The ultrasound may also show an empty amniotic sac or no sac. In this instance, the fetus stopped developing very early or was reabsorbed by the body. Sometimes, an empty amniotic sac is referred to as an anembryonic pregnancy or a blighted ovum.

There are times when a missed miscarriage is found during the anatomy scan (a mid-pregnancy scan performed between weeks 18 and 21 to examine the fetus for physical abnormalities). After 20 weeks, a fetus that passes away is called a fetal demise instead of a miscarriage. If the fetus develops up until close to 20 weeks or later, you will need medical care to deliver the fetus prematurely.

The healthcare provider may also order bloodwork to look at pregnancy hormones. Typically, your provider will draw labs several days apart to see if your hormone levels are going up or down. If they are not increasing, then a miscarriage is more likely.

In pregnancies that are very early on, it may be necessary to have a repeat ultrasound and bloodwork to confirm a miscarriage. This may happen when the dates are potentially off, and pregnancy may not be as far along as initially thought.

What Is the Best Way To Treat a Missed Miscarriage?

The best way to treat a missed miscarriage depends on a few factors, such as the stage of fetal development and the needs and preferences of the pregnant person. Generally, three different options are presented to individuals who have experienced a missed miscarriage. The choices include:

• Expectant management
• Medical management
• Surgical management

In some cases, such as with molar pregnancies, your healthcare provider may recommend surgical management over other options to ensure your safety and well-being. This is because molar pregnancies have the potential to cause severe bleeding and other health complications.

Expectant Management

Expectant management is often an acceptable option if an individual is in the first trimester. Expectant management means waiting to see if the body eventually miscarries and expels the pregnancy. This method is successful approximately 80% of the time.

Your provider may check in or have you call when you have passed the tissue. It will feel like a heavy period with moderate to heavy bleeding and cramping. You will receive instructions about how much bleeding is too much, and your provider may ask that you come in for testing to ensure the miscarriage is complete.

Follow-up testing may include blood work to ensure pregnancy hormones are decreasing and an ultrasound to confirm the passing of the gestational sac (embryo). If there is remaining tissue, a follow-up procedure may be required to remove the remaining parts of the pregnancy.

However, waiting can be very challenging psychologically or not a safe option if the pregnancy is farther along. Medical or surgical management are other options to consider.

Medical Management

Medical management involves an individual taking medications to induce the body to shed the contents of the uterus. The two medications typically used are mifepristone and misoprostol. Both are safe and effective options, and they can be used together to more significant effect.

Mifepristone causes the pregnancy tissue to detach from the uterine wall. Misoprostol causes the cervix to dilate and the uterus to contract, allowing the tissue to be expelled. The American College of Obstetricians and Gynecologists (ACOG) also recommends that patients receive pain management measures.

Similar to expectant management, you will experience mild to moderate bleeding and cramping. Your healthcare provider will follow up with you to ensure the miscarriage is complete. Follow-up may include an additional ultrasound or bloodwork.

This option gives the patient more control over the location and timing. Patients can feel a greater sense of control; they can be at home and as comfortable as possible and have support to help them through this difficult time.

Surgical Management

Surgical treatment offers immediate completion of miscarriage in cases of missed miscarriage with less follow-up required. The procedures typically used are dilation and curettage (D&C) or dilation and evacuation (D&E).

In both procedures, the cervix is dilated. A tool called a curette is used to remove the pregnancy tissue from the sides of the uterus. In D&E, aspiration is used to help remove the tissue from the uterus. Both procedures are done under anesthesia.

How Long Does It Take for a Missed Miscarriage to Pass?

The length of time it takes for a missed miscarriage to pass varies depending on the method chosen. Expectant management could take several weeks, depending on how far along the pregnancy is and when the body eventually miscarries. If the body does not miscarry within the timeframe the provider is comfortable with (usually two weeks), then medical or surgical management may be required.

Medical and surgical management takes much less time for the miscarriage to pass. With medical management, the medications typically begin working within a few hours, and the tissue from the miscarriage is passed within 48 hours.

You may still experience some bleeding and cramping for up to four to six weeks after the tissue passes. The bleeding should lighten to spotting within that four- to six-week timeframe.

With surgical management, your provider inserts an instrument through your cervix to remove the tissue. While the tissue is passed during the procedure, you may still bleed for several weeks after the procedure. The bleeding should lighten and turn into spotting.

Your healthcare provider will instruct you on how much bleeding is too much and other signs and symptoms that indicate you should contact a healthcare provider. Generally, large clots, bleeding that soaks a large pad in an hour, and a fever indicate you need medical care.

Pregnancy After Miscarriage

If you are hoping to become pregnant again, speak to your healthcare provider about when it is safe to try again. Most providers will recommend that you wait at least one to two weeks after completing a miscarriage to reduce infection risk. However, there are limited studies to provide evidence for the ideal timeframe to wait.

Repeated Miscarriages

Many individuals who have a miscarriage can become pregnant again and carry a baby to delivery.

However, in some cases, a healthcare provider will do additional testing, especially if you have three or more miscarriages. Things that your healthcare provider may look for include genetic screening for various chromosomal conditions associated with miscarriages and blood tests to screen for high levels of the antiphospholipid (aPL) antibody and lupus anticoagulant.

Antiphospholipid antibodies can increase the risk of blood clots and affect placental attachment to the uterine wall, reducing blood flow to the developing fetus.

Your healthcare provider may also do additional testing to see if there are structural abnormalities with your reproductive organs or other underlying health conditions affecting your ability to become and remain pregnant.

Coping

When you find out you have had a missed or silent miscarriage, you may feel overwhelmed and unprepared to participate in treatment decisions. In most cases, it's OK to take a few days to process what has happened before deciding what you will do next.

When you are ready, a healthcare provider can help you understand your options. Reach out to your loved ones for support. If you need to talk to a mental health professional, let a healthcare provider know you would like a recommendation or referral. Support groups may also be helpful.

Summary

A missed miscarriage happens when the fetus stops developing but has not been physically miscarried yet. If a person has a missed miscarriage, they might not have any symptoms. The condition might only be discovered when they have an ultrasound at a prenatal visit.

When a missed miscarriage is diagnosed, a person might be asked if they want to wait to see if the fetus will physically miscarry naturally. If this does not occur, medications and medical procedures can be used to complete the miscarriage.