What Does It Mean to Have a Threatened Miscarriage?

By (gynecologist), (embryologist), (gynecologist) and (fertility counselor).
Last Update: 11/23/2023

Threatened miscarriage is a state of alertness that suggests that a miscarriage may occur before the 20th week of pregnancy. Vaginal bleeding in the first weeks of gestation is a frequent symptom of this situation.

In addition to vaginal bleeding, other common symptoms are back and abdominal pain. However, these symptoms do not necessarily mean that a miscarriage will occur. Often the pregnancy will continue to progress normally.

In any case, if there is a suspected risk of miscarriage, it is very important to follow a series of precautions to reduce the chances of losing the fetus.

Why does threatened abortion occur?

A miscarriage is a type of abortion that occurs naturally, without using medicines or surgery to cause it, and it occurs quite often. In fact, it is estimated that about 40 percent of pregnancies end up in miscarriage, especially in women of advanced age.

The causes can have a fetal or maternal origin, although oftentimes, the exact cause is unclear. In fact, it can be due to a combination of factors (multifactorial).

Likewise, the exact cause of threatened abortion is not known, although it seems that there are some factors that seem to increase the probability of its occurrence.

This is the case, for example, of chromosomal alterations in the fetus or exposure to toxins. In addition, women over 40 years of age are more likely to suffer a threatened miscarriage.

Other factors that increase the risk of miscarriage are obesity, smoking, problems associated with the placenta (placenta previa or placental abruption), stress, uterine anomalies, infections during gestation, etc.

Why does threatened abortion occur?

There exist a series of symptoms or indicators of threatened miscarriage. Due to the varied nature causing them, it is crucial that you visit your doctor if you experience sigs of miscarriage. Only a well-versed specialists can determine if there is a real risk of miscarriage.

Among the most common symptoms of threatened miscarriage are the following:

Vaginal bleeding
It can include blood clots as well. Almost 50% of women who have this symptom in the first trimester end up miscarrying. Intrauterine hematomas (pooling of blood between the chorion and the uterine wall) are typically the cause behind it.
Abdominal cramps
Sharp pain in the abdominal area, similar to menstrual pain. They may be accompanied by vaginal bleeding.
Lower back pain
Acute low back pain that appears around the lumbar region.
Pregnancy symptoms
Symptoms of pregnancy may disappear progressively.

If you want to learn more about the causes of miscarriage, you can visit this article: Causes of miscarriage.


The first thing your doctor will do when a woman presents signs of an impending miscarriage is a vaginal or abdominal ultrasound to evaluate the amount of fluid, fetal development, and fetal heart rate. Additionally, he or she will conduct a pelvic exam to check your cervix.

Also, you may be required to provide a blood test in order to determine:

  • Beta-hCG levels in different days or weeks to confirm that the pregnancy progresses
  • A complete blood count (CBC) to determine the amount of blood your are losing
  • Progesterone levels
  • The amount of white blood cells (WBCs) to check if there exists an infection

Depending on the results obtained in each of these tests, the specialist will decide the best way to proceed in each situation.

Treatment for threatened abortion

When there is a threatened miscarriage, your doctor will determine the steps to take. Some recommendations when there is a risk of miscarriage are:

  • Avoid sexual intercourse
  • Partial or total rest, based upon the degree of severity of the symptoms
  • Don't eat sausages or unprocessed meat
  • Avoid over-the-counter drugs

Also, we recommend that you follow healthy lifestyle habits, with a balanced diet that contains all necessary nutrients, and avoiding drug, tobacco, and alcohol use.

One should take into account that a threatened miscarriage is NOT a miscarriage. For this reason, you should keep calm and avoid stress. Seek emotional support if you need it and follow your doctor's instructions strictly.

In some cases, progesterone is administered as a prevention measure, although its effectiveness has been a controversial issue lately. Some detractors argue that it is useless to prevent miscarriages, although its effectiveness has been proven when it comes to treating recurrent miscarriages (i.e. when a woman has experienced three or more pregnancy losses).

FAQs from users

Is there an increased risk of miscarriage in pregnancies achieved using reproductive technologies?

By Carmen Ochoa Marieta M.D., Ph.D., M.Sc. (gynecologist).

No, the risk of miscarriage once a woman achieves pregnancy, whether naturally or through assisted conception, is exactly the same.

Can sperm quality increase the risk of miscarriage?

By Sergio Rogel Cayetano M.D. (gynecologist).

Indeed, the presence of abnormalities in sperm DNA or any other inherent characteristics of the semen can increase the risk of miscarriage directly. Such abnormalities are more common in men with abnormal semen analysis results, although sometimes are present in males with normal semen analyses.

In patients with recurrent miscarriages, evaluating the sperm DNA fragmentation, percentage of apoptotic sperm cells, and performing a FISH (fluorescence in situ hybridization) analysis is recommendable.

How long can a threatened miscarriage last? Can it be stopped?

By Rebeca Reus BSc, MSc (embryologist).

The duration of a threatened miscarriage varies from woman to woman. For this reason, your OB/GYN must determine the severity of the situation on a case-by-case basis. In general, a threatened miscarriage occurs during the first trimester of pregnancy is the majority of the cases. However, actually it can extend up to week 20 of pregnancy.

How long do you bleed during a threatened miscarriage?

By Rebeca Reus BSc, MSc (embryologist).

The bleeding of a threatened miscarriage varies by patient—there is no particular duration of vaginal bleeding during pregnancy that confirms a threatened miscarriage. The risk of miscarriage depends on two factors: the characteristics and the duration of the bleeding. For instance, the more abundant it is, the higher the chances of miscarrying.

Should I return to work with a threatened miscarriage?

By Rebeca Reus BSc, MSc (embryologist).

Indeed, a threatened miscarriage is a cause of time off work, although it depends on the level of risk of each woman. It depends on the clinical symptoms experienced by the woman and the type of work she does. Again, it should be determined by your physician.

Suggested for you

Throughout this post, we have seen that vaginal bleeding is a common symptom of threatened miscarriage. Nonetheless, the cause is not always an impending miscarriage. Click here to learn more about other potential causes of bleeding during pregnancy: Bleeding During Pregnancy – What’s Normal & What’s Not?

Did you know that there exist different types of miscarriage? If you want to be familiar with each one of them, do not miss this guide: What Are the Different Types of Miscarriage? – Definition & Causes.

We make a great effort to provide you with the highest quality information.

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FAQs from users: 'Is there an increased risk of miscarriage in pregnancies achieved using reproductive technologies?', 'Can sperm quality increase the risk of miscarriage?', 'How long can a threatened miscarriage last? Can it be stopped?', 'How long do you bleed during a threatened miscarriage?' and 'Should I return to work with a threatened miscarriage?'.

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Authors and contributors

 Carmen Ochoa Marieta
Carmen Ochoa Marieta
M.D., Ph.D., M.Sc.
Bachelor's Degree in Medicine from the Basque Country University. PhD in Medicine & Surgery from the University of Murcia. Currently, she is the director of the Assisted Reproduction Unit of Centro de Estudios para la Reproducción (CER SANTANDER) in Santander, Spain, as well as the director of the Diagnostic Unit of Human Assisted Reproduction in Bilbao. More information about Carmen Ochoa Marieta
License: 484805626
 Rebeca Reus
Rebeca Reus
BSc, MSc
Degree in Human Biology (Biochemistry) from the Pompeu Fabra University (UPF). Official Master's Degree in Clinical Analysis Laboratory from the UPF and Master’s Degree about the Theoretical Basis and Laboratory Procedures in Assisted Reproduction from the University of Valencia (UV). More information about Rebeca Reus
 Sergio Rogel Cayetano
Sergio Rogel Cayetano
Bachelor's Degree in Medicine from the Miguel Hernández University of Elche. Specialist in Obstetrics & Gynecology via M. I. R. at Hospital General de Alicante. He become an expert in Reproductive Medicine by working at different clinics of Alicante and Murcia, in Spain, until he joined the medical team of IVF Spain back in 2011. More information about Sergio Rogel Cayetano
License: 03-0309100
Adapted into english by:
 Sandra Fernández
Sandra Fernández
B.A., M.A.
Fertility Counselor
Bachelor of Arts in Translation and Interpreting (English, Spanish, Catalan, German) from the University of Valencia (UV) and Heriot-Watt University, Riccarton Campus (Edinburgh, UK). Postgraduate Course in Legal Translation from the University of Valencia. Specialist in Medical Translation, with several years of experience in the field of Assisted Reproduction. More information about Sandra Fernández

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