Incomplete Abortion: Causes, Symptoms, Diagnosis & Treatment

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An incomplete abortion or incomplete miscarriage is when some products are held back in the uterus after a miscarriage (1).

It is also referred to as spontaneous abortion. The products of conception retained in the uterus do not have viable fetuses. This implies that there is no possibility to continue the pregnancy after an incomplete abortion.

It is essential to recognize the signs early for timely medical intervention and to prevent complications. The right diagnosis helps ensure complete expulsion of the tissue remains left in the womb after an abortion.

Read this post to know about the causes, risk factors, symptoms, diagnosis, treatment, and complications of incomplete abortion.

How Common Is Incomplete Abortion?

There is no global statistical data on incomplete abortion since abortion is legalized in some countries and may go unreported in a few countries.

A comprehensive study on medical abortions divulged a significant surge in complications at less than 12 weeks. The rate of complications shot up from 4.2% to 8.2% between 2008 and 2015. An incomplete abortion, marked as the most common complication, was observed in 57% of all medical abortions. The graph below shows the frequency of incomplete abortion as a complication in medical abortions from 2008 to 2015. Through the years, its numbers dwindled, yet it remained the most common complication.

The prevalence of complications in medical abortions

What Are The Risk Factors And Causes Of Incomplete Abortion?

Approximately 50% of incomplete abortions can be due to chromosomal anomalies in the fetus, and they are not preventable.

Other causes and risk factors for incomplete abortion could be (2):

• Maternal diseases such as diabetes, renal diseases, thyroid problems, lupusⁱAn autoimmune disease that is inflammatory in nature. , hypertension, thrombophiliaⁱA condition where blood forms clot easily. , and polycystic ovarian syndromeⁱA hormonal disorder characterized by high levels of male hormones in female bodies leading to multiple cysts on the ovaries.
• Abnormalities of uterus
• Exposure to teratogensⁱSubstances that cause fetal abnormalities upon exposure during pregnancy. such as radiation, toxins, drug, alcohol, or excessive caffeine
• Infections such as sexually transmitted infections (STIs), listeriosis (caused by bacteria Listeria monocytogenes), and human immunodeficiency virus infection
• Overweight or underweight

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• Advanced maternal age
• Hydatidiform moleⁱA rare uterine mass present at the start of pregnancy.

Some of these causes and risk factors can also result in congenital anomalies, leading to incomplete abortions. Incomplete abortions are more common with advanced maternal age since the risk of chromosomal abnormalities is higher in pregnancies with advanced maternal age. However, young women can also have an incomplete abortion if any other risk factors or causes are present (2).

Less reported causes of incomplete abortions may include (2):

• Illegal abortions
• Lack or poor prenatal care
• Pelvic or lower abdominal trauma

Rarely, incomplete abortions can also occur after a medical or surgical abortion (2). Here, remaining pregnancy tissue will not be completely passed after medical abortion or removed during a surgical abortion. It happens more often after medical abortion than surgical abortion.

Quick fact

Women, typically aged 15 to 20 years, diagnosed with hydatidiform moles have a 13% chance of incomplete abortion (2).

What Are The Signs And Symptoms Of Incomplete Abortion?

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Moderate to severe vaginal bleeding and pelvic or lower abdominal pain are common symptoms of incomplete abortion.

The other symptoms you may notice after a few days of abortion are (3):

• Pain lasting more than a few days
• Excessive bleeding lasting for a few days
• Severe pain or cramps
• Discomfort or pain while pressing on the abdomen (belly)
• High fever lasting more than a day or two
• Symptoms of low blood pressure such as dizziness
• Persistent foul odor from vaginal discharge

You may contact an obstetrics and gynecology specialist if you have any symptoms of incomplete abortion since early medical care is essential for better outcomes.

Things to know

The pelvic pain in case of incomplete abortion may radiate to the lower back, buttocks, genitalia, and perineum (2).

How Is Incomplete Abortion Diagnosed?

Symptoms and soft uterus on the bimanual examⁱA two-handed pelvic exam performed by a doctor to assess the size and location of organs. by a doctor can suggest a diagnosis of incomplete abortion. The following tests are ordered to confirm the diagnosis of incomplete abortion (2):

• Human chorionic gonadotropin (hCG) levels in the blood. Usually, hCG levels are low after a few days of an abortion.
• Transabdominal or transvaginal ultrasound helps visualize retained products of conception in the uterus.
• Blood analysis, including complete blood count, blood type, and coagulation profile, can detect Rh factor, risk of bleeding, etc.

These diagnostic tests are necessary before treating an incomplete abortion since similar clinical presentations can be seen in ectopic pregnancy.

How Is Incomplete Abortion Treated?

Treatment for incomplete abortion may vary depending on the clinical presentation and gestational age. However, medical or surgical interventions are usually recommended to evacuate retained products of conception (ERPC)ⁱA procedure to remove conception products from the womb following an abortion or miscarriage. . Treatment strategies based on the clinical scenario may include (2) (4) the following:

• Surgical evacuation is recommended for women with heavy bleeding and signs of infection. Vacuum aspirationⁱAn abortion procedure that removes the fetus/embryo through the cervix using a vacuum. or curettage procedures are used to remove the retained products of conception (POC). Medical management is not recommended for unstable patients.

• Incomplete abortions in stable cases are treated with medical management using misoprostolⁱA medication used to treat stomach ulcers, induce labor, or cause an abortion. or surgical procedures depending on resources and women’s preferences.

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• Doctors may recommend expectant management in early pregnancy failure (EPF). This is waiting for the natural passage of conception products. Usually, the POC is passed within one to four weeks of pregnancy failure after embryonic death. Medical or surgical interventions are suggested if the natural passage is delayed or has complications.

• Blood transfusion and medication are often required for women with severe bleeding.

• Oxytocin is given to help control bleeding caused by uterine atony.

• Rh immune globulin injections are given in cases of Rh incompatibility to help prevent complications in a future pregnancy.

• Products of conception fragments from the cervical opening are removed with forceps to help prevent cervical shock.

• IV fluids and pain medications are given if needed.

Reproductive health is often not compromised in cases of incomplete abortions, and the prognosis is generally positive after proper management. There is an 80-96% success rate with no future fertility problems. Also, there are no major differences between outcomes of expectant and medical management of incomplete abortion when gestational age is less than 12 weeks.

Quick fact

Rh-negative females require RhoGam shot to prevent the formation of antibodies which may cause issues in the future pregnancy (12).

What Are The Complications Of Incomplete Abortion?

Untreated incomplete abortion may lead to various complications and affect maternal health (2):

• Severe bleeding and hemorrhagic shock (poor oxygen supply due to blood loss)
• Sepsis (blood infection) due to incomplete septic abortion and septic shock (low blood pressure due to sepsis)
• Cervical shock is a vasovagal effectⁱThe body's reaction, such as fainting due to triggers due such as the sight of blood or intense emotions. , causing bradycardia (slow heart rate) and hypotension (low blood pressure) due to products of conception in the cervix.

There is a 3.4% increased risk of poor prognosis if the gestation age is more than 12 weeks. Increased uterine size, fetus size, and blood supply could be the reasons for unfavorable outcomes in advanced weeks of gestation (2).

Common complications of incomplete abortions after 12 weeks may include (2):

• Sterility
• Maternal death

The risk for serious complications, including maternal death, is more after 14 weeks of gestation. Lack of adequate medical care and delaying seeking medical care are common reasons for severe complications (2). It is recommended to seek medical care from approved healthcare providers since inadequate procedures could result in uterine rupture, uterine perforation, pelvic infections, and cervical damages.

How To Cope With Incomplete Abortion?

The following coping strategies can help you deal with emotional issues related to incomplete abortion (5):

• You may understand that miscarriage is common, and it often occurs when there is a genetic abnormality or other problems that prevent normal fetal development. Surgical and medical abortions are also done in circumstances when there is a certain risk.

• Know that everyday activities such as working, exercising, and having sex do not cause miscarriage, and do not blame yourself for pregnancy loss.

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• Understand that emotions can be due to sudden hormonal shifts in the body. A sudden drop in pregnancy hormones leads to a roller coaster of emotions.

• Most experts recommend grieving your loss and overcoming it.

• Coping as a couple is necessary to recover from pregnancy loss. Men can also be emotional about pregnancy loss and feel sad or guilty. Avoid blaming each other, support and open up.

Image: IStock

• Seek counseling and support group.

What Is The Difference Between A Complete Abortion And An Incomplete Abortion?

When everything from a miscarriage has come out of the uterus, it’s called a completed miscarriage. The bleeding and pain should go away quickly. An ultrasound or a surgical procedure called dilation and curettage (D&C) can confirm a completed miscarriage (6). If it is a complete miscarriage, you usually will not require medical help.

An incomplete miscarriage is when a miscarriage starts, but not everything from the pregnancy comes out (7). You might feel pain in your abdomen or back and see bleeding when your cervix is open. If the cervix dilates or effaces, or if the membranes rupture, a miscarriage is unavoidable. If the miscarriage isn’t complete, you may still have bleeding and cramps (6).

Seek healthcare professionals’ advice to plan the next pregnancy. Although it is safe to conceive after one normal menstrual cycle, some women may require certain medical tests to determine the cause of incomplete abortion. This may help prevent future pregnancy loss. It is also advised to wait until you are physically and emotionally ready to conceive again.

Infographic: WHO Recommendations On Incomplete Abortion Care

According to human rights organizations and courts worldwide, abortion care is a fundamental right of a woman or a girl. Healthcare providers are obligated to provide high-quality abortion care. Go through the infographic to know WHO recommendations on incomplete abortion care.

Illustration: Momjunction Design Team

Illustration: Incomplete Abortion: Causes Symptoms Diagnosis & Treatment

Image: Dall·E/MomJunction Design Team

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Dr. Mona HardasMD

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Rebecca is a pregnancy writer and editor with a passion for delivering research-based and engaging content in areas of fertility, pregnancy, birth, and post-pregnancy. She did her graduation in Biotechnology and Genetics from Loyola Academy, Osmania University and obtained a certification in ‘Nutrition and Lifestyle in Pregnancy’ from Ludwig Maximilian University of Munich (LMU).

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