Miscarriage

What is Miscarriage?

The terms used to describe the loss of a pregnancy before the fetus can survive outside the womb differ in various medical journals and have changed over time. Traditionally, the term “spontaneous abortion” was used to describe natural pregnancy loss before 20 weeks. However, the term has been gradually replaced in medical literature since many patients prefer the term “miscarriage” to avoid the stigma associated with the term “abortion”. The reVITALize gynecology definitions, endorsed by many American professional organizations including the American College of Obstetricians and Gynecologists (ACOG), now recommend the terms “miscarriage” or “intrauterine pregnancy loss”. Both of these terms mean the loss of a nonviable pregnancy, which is a pregnancy not expected to develop normally.

Some organizations define an early miscarriage as a pregnancy loss before 10 weeks. The ACOG and the European Society of Human Reproduction and Embryology (ESHRE) use the similar term “early pregnancy loss”. ACOG defines it as a loss occurring within the first 12 weeks and 6 days of pregnancy, but the ESHRE’s definition refers to a loss occurring before 10 weeks. This text will use the term “early pregnancy loss”, which will be defined according to ACOG’s definition of a nonviable pregnancy loss within the first 12 weeks and 6 days of gestation.

Early pregnancy loss can be diagnosed at different stages and can be classified as follows:

“Biochemical pregnancy loss” is a term used when human chorionic gonadotropin levels (the hormone that indicates pregnancy) decreases without any pregnancy ever being detected on ultrasound. This type of miscarriage generally happens before 6 weeks of pregnancy in cases where reproductive technology was used.

“Asymptomatic pregnancy loss” (also known as ‘missed abortion’) is where the fetus or embryo dies without any symptoms or expulsion of the fetus and its surroundings.

“Threatened pregnancy loss” refers to when symptoms like bleeding and cramping occur, indicating a possible early pregnancy loss. However, the entrance of the uterus remains closed and the fetus or embryo is still alive on ultrasound.

“Inevitable pregnancy loss” is when the entrance of the uterus is open despite the presence of the above symptoms. This term is not popular since it can be hard to accurately diagnose this type of loss

“Incomplete pregnancy loss” refers to when parts of the pregnancy remain within the uterus despite the detection of an early pregnancy loss.

“Complete pregnancy loss” is when all parts of the pregnancy are expelled.

“Recurrent pregnancy loss” is when several pregnancies are lost consecutively. The definition of ‘recurrent’ varies, with some organizations using it to describe two or more losses’, others use it for three consecutive losses.

“Septic miscarriage” is an early pregnancy loss complicated by an infection within the uterus. It is rare and usually happens as a result of non-sterile abortion procedures.

What Causes Miscarriage?

Most early pregnancy losses, which occur between 6 to 10 weeks of pregnancy, are believed to be due to problems with the baby’s chromosomes, such as having too many or too few. This happens in more than 60% of cases. Sometimes, problems with the immune system or inflammation can also play a part, likely because it affects the development of the placenta.

The risk of losing a pregnancy early increases with the mother’s age. For example, the chances of this happening are around 9% to 17% for women aged 20 to 30, but it jumps to 75% to 80% for women who are 45. The risk also climbs with every loss; a woman has about a 20% chance of losing a future pregnancy after one miscarriage, 28% after two consecutive miscarriages, and 43% after three or more consecutive miscarriages. Bleeding during the first three months of pregnancy, which happens in up to a quarter of pregnancies, is also linked to a higher risk of loss.

Certain long-term health conditions can make a woman more likely to have an early pregnancy loss, such as obesity, diabetes, too much prolactin, celiac disease, thyroid disease, and autoimmune conditions, particularly antiphospholipid syndrome. Some infections, like syphilis, parvovirus B19, Zika virus, and cytomegalovirus, can also increase the risk. Structural problems with the uterus and having an intrauterine device (IUD) can also lead to a higher risk.

Chronic stress, caused by social issues like racism, housing or food insecurity, or living under threats of violence, is also linked to a higher risk of losing a pregnancy early. Modifiable lifestyle factors, like drinking alcohol, smoking, using cocaine, and drinking more than 3 cups of coffee a day, can also increase risk. Finally, exposure to environmental toxins like arsenic, lead, and organic solvents may raise the risk of early pregnancy loss.

Risk Factors and Frequency for Miscarriage

Early pregnancy loss, commonly known as miscarriage, occurs in about 10 to 20 percent of known pregnancies. However, these percentages may not fully represent the actual occurrences as many miscarriages often go unrecognized and the bleeding is sometimes wrongly perceived as a heavy, late period. Research involving daily tracking of pregnancy hormones, specifically serum β-hCG levels, suggest that miscarriages may occur in nearly 38 percent of pregnancies. Also, when bleeding occurs in the first trimester, it can potentially indicate a miscarriage in 12 to 57 percent of pregnancies.

Signs and Symptoms of Miscarriage

When a pregnant patient experiences bleeding during the first trimester, it’s essential to evaluate for a potential pregnancy loss. This involves determining if the patient is stable, ruling out other possible conditions like ectopic or molar pregnancies, and verifying the viability or non-viability and stage of the pregnancy.

Symptoms of early pregnancy loss can vary depending on the stage or type of loss. Patients may not show any symptoms in the case of a missed abortion, only showing a gradual decrease in typical pregnancy symptoms like nausea or tiredness. Other types of pregnancy loss frequently present with symptoms such as pelvic cramping and vaginal bleeding. Key details of the patient’s history of vaginal bleeding must be noted. Things such as the first day of the patient’s last menstrual period, when the abnormal uterine bleeding began, the number of soaked pads in an hour, and the presence and size of clots. In severe cases of septic miscarriages, additional symptoms may include uterine tenderness, a purulent cervical and vaginal discharge, and systemic signs like fever, rapid heartbeat, and low blood pressure.

Physical examination consists of checking for signs of pregnancy loss and conducting a comprehensive abdominal and pelvic examination to assess if the patient is experiencing hemodynamic instability or if there is a potential ectopic pregnancy. During the abdominal examination, the presence of signs of an ectopic pregnancy or a septic abortion extending beyond the uterus are noted. The pelvic exam should include a speculum-induced visualization of the cervix and bimanual palpation, crucial for evaluating a suspected miscarriage.

Findings that might indicate early pregnancy loss include the state of the cervix (open or closed), the presence or absence of pregnancy tissue in the cervical opening, vaginal bleeding, and signs suggestive of a septic abortion such as purulent discharge, uterine or cervical motion tenderness. In contrast, the finding of an adnexal mass suggests an ectopic pregnancy instead of an early pregnancy loss. The volume of vaginal bleeding should be estimated during the pelvic exam as part of the hemodynamic stability assessment. This can be done by observing how quickly blood fills the vaginal vault, which may be significant even if there’s no sepsis. Bleeding that’s similar to or greater than typical menstrual bleeding suggests an early pregnancy loss.

Testing for Miscarriage

The first steps in assessing a potential early pregnancy loss are to confirm the pregnancy is in the uterus and to check whether the pregnancy is viable (can continue to term). It’s important to make an accurate diagnosis before starting any treatment, to avoid ending a normal pregnancy or causing birth defects.

The investigation usually starts with two tests:

• Pelvic ultrasound
• Quantitative serum β-hCG level (a hormone produced during pregnancy)

Doctors also consider the date of the last menstrual period (LMP) and any earlier ultrasound images from the current pregnancy. The LMP helps estimate how far along the pregnancy is, and the ultrasound can confirm this estimate and show where the pregnancy is located (for example, in the uterus or elsewhere).

Other tests that may be needed include:

• Checking hemoglobin and hematocrit levels, to look for anemia caused by acute blood loss (although large blood losses may not be reflected accurately in these levels).
• Identifying the mother’s ABO blood type and Rh status (positive or negative), to prepare for possible blood transfusion or to see if anti-Rh immunoglobulin is needed.
• A wet mount test and bacterial and viral cultures of cervical, urine, blood, and evacuated tissue to look for possible septic abortion.

The precise location of a pregnancy can be established once ultrasound can detect shapes like a yolk sac or fetal pole inside an intrauterine gestational sac. If an intrauterine pregnancy has been previously confirmed, a diagnosis of early pregnancy loss can be made based on the ultrasound’s absence of products of conception and specific clinical features. For pregnancies that are too early in their gestation for the ultrasound to show fetal heart activity (usually less than 6 weeks), a drop in hCG levels over 48 to 72 hours can aid diagnosis.

For pregnancies that are too early in their gestation for the ultrasound to show fetal heart activity, a decrease in β-hCG levels over 48 to 72 hours can assist in diagnosing early pregnancy loss. However, before a heartbeat can develop, an ultrasound can help establish whether a pregnancy is viable but may require multiple scans over several weeks.

If the location of a pregnancy is still unknown after the initial ultrasound, trending β-hCG levels over several days can help determine the pregnancy’s age and location and rule out an ectopic pregnancy. An estimated due date (EDD) can be determined based on a precise LMP. This EDD is then compared to the EDD calculated using ultrasound. It’s essential to consider the complete clinical picture during evaluation and not rely solely on either the LMP-derived due date or a single β-hCG level.

Patients should be closely observed until the exact location of the pregnancy is identified (that is, when ultrasound clearly shows a yolk sac and fetal pole inside a gestational sac). This usually involves monitoring β-hCG levels every 48 to 72 hours, with repeat ultrasounds (usually done at the same time as the repeat β-hCG levels) until the pregnancy’s location is confidently confirmed or β-hCG levels fall to nonpregnant levels (that is, zero).

In a viable pregnancy, β-hCG levels rise at a relatively predictable rate. If the β-hCG level doesn’t increase at the minimum expected rate, ectopic pregnancy should be strongly suspected. A decrease in β-hCG levels usually suggests a failing pregnancy. However, ectopic pregnancies can initially have a decrease in β-hCG followed by an abnormal increase. Therefore, if the location of the pregnancy hasn’t been confidently identified on ultrasound, the β-hCG level should be monitored until nonpregnant levels are reached to make sure an ectopic pregnancy is not missed.

Treatment Options for Miscarriage

Early pregnancy loss can be handled in three different ways: expectantly (waiting for it to happen naturally), medically (using medicine), or surgically, depending on the specific clinical factors at play. Studies suggest that patients who are allowed to choose their preferred treatment method often experience better mental health outcomes and are more satisfied with their care. However, regional guidelines tend to differ.

The Management Choices

Expectant and medical management are not preferable in situations where there’s a risk of heavy bleeding or infection. For example, it’s not recommended for people in their second trimester, people with bleeding disorders, or people with cardiovascular disease.

Expectant management can generally continue for as long as the patient desires, unless infection or heavy bleeding develops. Usually, around 70% to 80% of early pregnancy losses will naturally complete within 1-2 months, and this method tends to work better in symptomatic patients.

Medical management has the same efficiency when it comes to handling first-trimester incomplete pregnancy losses. It involves using a drug called misoprostol. If the expulsion of pregnancy does not occur, the dose can be repeated. To enhance the success rate of the drug, it’s recommended to use another medicine, mifepristone, 24 hours before the first dose of misoprostol.

The side effects of these treatments include vaginal bleeding, cramping, diarrhea, and nausea. Patients should also be provided with appropriate pain relief during the process, such as nonsteroidal anti-inflammatory drugs (NSAIDs), but antibiotics should only be used if an infection is present.

As for surgical management, it’s generally used for patients who can’t tolerate heavy bleeding. It often involves a method known as uterine aspiration or dilation and suction curettage and is the best choice for patients who have cases of uterine hemorrhage or septic miscarriages.

The Management Approach

Generally, patients should be allowed to choose the management strategy they prefer, unless their condition demands surgical treatment. Patients may choose one approach over another based on factors like the level of control, total time, expected success rates, and their previous experiences.

For instance, some patients may prefer a more “natural” process and be willing to wait for miscarriage completion, while others may prefer an immediate and definitive surgical management. The specific type of pregnancy loss can also affect the decision. For example, symptomatic and incomplete losses tend to respond better to expectant or medical management than to surgical treatment.

In cases of septic abortion, the primary treatment after the patient’s stabilization is a fast surgical evacuation of the uterus. Antibiotics should also be administered to the patient as soon as possible before undertaking the surgical operation, and the choice of antibiotics should be individualized.

Regarding contraception, patients can opt for hormonal contraception once the early pregnancy loss is completely resolved. An intrauterine device can be placed immediately after surgical evacuation of the uterus but is contraindicated in the presence of an intrauterine infection.

What else can Miscarriage be?

When diagnosing early pregnancy loss, doctors should consider several possible causes, especially those typically linked to early pregnancy bleeding. These could include:

• Ectopic pregnancy: This is when the pregnancy develops outside the uterus, leading to symptoms like abdominal cramping, unusual vaginal bleeding, and an untypical increase in a pregnancy hormone called β-hCG. An ultrasound might show a mass outside the uterus.
• Subchorionic hematoma: This is a bleeding that occurs between the placenta and the uterine wall. It often results in vaginal bleeding and could lead to a threatened miscarriage or even the complete loss of the pregnancy.
• Gestational trophoblastic disease: This happens when there’s an abnormal growth inside the uterus. It causes symptoms such as bleeding during pregnancy, an unusually enlarged uterus, extremely high β-hCG levels, and severe morning sickness. An ultrasound may show a speckled pattern inside the uterus and swollen ovaries.

It’s also important to consider possible issues with the cervix and vagina, like infections, polyps, changes in the cervix’s shape or cell structures, or traumas, especially if there was bleeding after sexual contact. Random bleeding during pregnancy or bleeding due to the implantation of the embryo in the uterus should only be considered if all other possibilities have been ruled out.

Usually, these potential diagnoses can be sufficiently evaluated by understanding the patient’s medical history, carrying out a physical exam, and using pelvic ultrasound.

What to expect with Miscarriage

Severe complications like shock and septic miscarriage after an early pregnancy loss are quite uncommon. Moreover, the likelihood of such complications remains low regardless of the method of management – be it natural, medical, or surgical. As such, the general outlook for women experiencing early pregnancy loss tends to be positive. Yet, in low-income countries, complications like bleeding and infection after a miscarriage can lead to maternal death, particularly where access to high-quality obstetric care is limited due to social and economic conditions.

It’s also important to remember that a miscarriage can have emotional effects as well. Many women and their partners may experience feelings of loss, guilt, anxiety, and depression in the weeks or even months following a miscarriage. This is particularly true in cases of recurrent losses, fertility issues, loss of a highly desired pregnancy, and among women with existing mental health conditions. While there isn’t much research to support the effectiveness of psychological counseling in these situations, addressing these feelings early on can improve outcomes. Also, trying to conceive soon after an early pregnancy loss is safe, and those who try within three months of a miscarriage typically have higher success rates for subsequent pregnancies and live births.

Recurrent pregnancy loss, which is often defined as the spontaneous loss of 2 to 3 pregnancies, affects fewer than 5% of patients who experience two consecutive losses and only 1% who experience three or more. In these cases, doctors typically recommend tests to look for a potential underlying cause. This includes genetic testing of both parents and an assessment of the mother for conditions that might affect hormones, the uterus, or the presence of the antiphospholipid syndrome, a disorder that can lead to recurrent miscarriages.

Possible Complications When Diagnosed with Miscarriage

Pregnancy loss in the early stages can sometimes lead to complications, including:

• Remnants of the pregnancy left in the body
• Bleeding that leads to complications due to low blood volume
• Infections
• Injuries from surgical management, like cuts in the cervix or holes in the uterus
• A clotting disorder known as DIC
• The postabortion triad, which is characterized by a low-grade fever, pain, and bleeding
• Hematometra, or blood accumulation in the uterus
• A rare complication known as cervical shock, where remnants of the pregnancy in the cervical canal trigger a bodily response that leads to low blood pressure and slow heart rate. This typically doesn’t respond to IV fluids but quickly gets better after the remnants are removed from the cervix.

There are also complications that can happen due to septic miscarriage, such as:

• Sepsis syndrome
• DIC
• Toxic shock syndrome
• Acute injury to the kidneys
• Acute respiratory distress syndrome
• Necrotizing fasciitis, a severe bacterial infection leading to tissue death
• Future infertility due to scarring of the fallopian tubes

Preventing Miscarriage

Pregnant people should be advised to avoid behaviors that can increase the risk of miscarriage, such as smoking and using cocaine. They should also try to improve their diet. However, there’s no one-size-fits-all way to prevent miscarriage. Strategies like bed rest, medications to stop premature labor, blood thinners, and extra β-hCG (a hormone produced during pregnancy) have not been proven to lower the risk of losing a pregnancy early on. Only women with a specific condition called antiphospholipid syndrome have been shown to benefit from taking aspirin and blood thinners to reduce the likelihood of miscarriage. Similarly, additional progesterone, another hormone, has only been shown to prevent early pregnancy loss in those who have experienced recurring miscarriages.