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.

The right diagnosis helps ensure complete expulsion of the tissue remains left in the womb after an abortion. This post lets you understand the causes, symptoms, risk factors, treatment, and complications of incomplete 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.

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, lupus, hypertension, thrombophilia, and polycystic ovarian syndrome
  • Abnormalities of uterus
  • Exposure to teratogens 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
  • Advanced maternal age
  • Hydatidiform mole

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.

What Are The Signs And Symptoms Of Incomplete Abortion?

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

You may contact a doctor if you have any symptoms of incomplete abortion since early medical care is essential for better outcomes.

How Is Incomplete Abortion Diagnosed?

Symptoms and soft uterus on the bimanual exam 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). 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 aspiration 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 misoprostol or surgical procedures depending on resources and women’s preferences.
  • 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.

Most women with incomplete abortions have a good prognosis after 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.

What Are The Complications Of Incomplete Abortion?

If left untreated, the following complications might occur from an incomplete abortion (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 effect, 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.
  • 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.
  • Seek counseling and support group.

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.

Frequently Asked Questions

1. How long does it take for an incomplete abortion to pass?

It can take weeks for an incomplete abortion to pass. However, if misoprostol is used, the tissue usually passes within a week. It is advisable to consult a doctor when using any medications (6).

2. Can antibiotics treat incomplete abortion?

Women seeking treatment for an incomplete abortion usually have problems due to excessive bleeding or infection. Antibiotics cannot treat an incomplete abortion but may prevent or treat infections. Single-dose antibiotics may be more suitable if it is difficult to follow a continued antibiotic regimen (7).

Inform your doctor if abdominal pain and bleeding after an abortion or miscarriage is not improved within a few days. Incomplete abortion needs medical care since retention of pregnancy remains in the uterus can result in life-threatening complications. Seek counseling for yourself and as a couple to cope with pregnancy loss.

Key Pointers

  • Incomplete abortion is a condition where some fetal material remains within the body.
  • Symptoms of incomplete abortion are pain, cramps, excessive bleeding lasting more than a few days, high fever, or dizziness.
  • It can be treated by surgical evacuation and medical management such as misoprostol.


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Dr Bisny T. Joseph

Dr. Bisny T. Joseph is a Georgian Board-certified physician. She has completed her professional graduate degree as a medical doctor from Tbilisi State Medical University, Georgia. She has 3+ years of experience in various sectors of medical affairs as a physician, medical reviewer, medical writer, health coach, and Q&A expert. Her interest in digital medical education and patient education made... more

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