Threatened miscarriage, also called threatened abortion, describes a situation during early pregnancy when vaginal bleeding or cramping occurs, but the pregnancy may continue normally. Understanding the available approaches to manage this condition can help ease concerns during a difficult and uncertain time.

When pregnancy shows warning signs

A threatened miscarriage occurs when a pregnant person experiences mild vaginal bleeding with or without abdominal cramping during the early stages of pregnancy. This condition most commonly happens in the first trimester, up to 13 weeks, though it can occur anytime before 20 weeks of pregnancy. The term “threatened” means that while these symptoms are worrying, the pregnancy has not yet ended and may very well continue to term. The main goal of treatment is to monitor the situation closely, provide support, and help ensure the best possible outcome for both the mother and the developing baby.^[1]

This condition is surprisingly common, affecting about 15% to 20% of all pregnancies before 20 weeks. Many people are alarmed when they notice bleeding during pregnancy, and understandably so. However, it’s important to know that experiencing vaginal bleeding or mild cramping does not automatically mean that a miscarriage will happen. In fact, studies show that among pregnant women who had some vaginal bleeding in the first 20 weeks, about 60% went on to carry their pregnancy to full term at 37 weeks. This means that in many cases, the pregnancy continues and a healthy baby is born.^[1]

The main aim of treating threatened miscarriage is not necessarily to prevent miscarriage—because in many cases, if a miscarriage is going to happen, it cannot be stopped—but rather to closely monitor the pregnancy, provide reassurance, and manage symptoms. Healthcare providers focus on confirming that the pregnancy is viable, ruling out other complications, and supporting the pregnant person through this stressful period. Treatment approaches vary depending on the individual situation, including how far along the pregnancy is and whether there are any additional risk factors present.^[2]

Standard approaches to managing threatened miscarriage

The cornerstone of managing a threatened miscarriage is what doctors call expectant management, which essentially means careful observation and watchful waiting. When a person presents with symptoms of threatened miscarriage, healthcare providers first conduct a thorough evaluation to understand what is happening. This typically involves asking about symptoms and medical history, performing a pelvic examination to check whether the cervix is closed, and ordering an ultrasound to look for the baby’s heartbeat and confirm that the pregnancy is located inside the uterus.^[2]

Blood tests are another important part of standard care. Providers often check levels of human chorionic gonadotropin (HCG), known as the pregnancy hormone, and progesterone. In a healthy pregnancy, HCG levels rise steadily, sometimes doubling every few days, especially in the early weeks up to about 11 weeks. If HCG levels drop over several days before 11 weeks, it may suggest that a miscarriage is likely. However, in a threatened miscarriage, HCG levels may remain steady, indicating that the pregnancy is still viable. Providers usually recheck these levels every two to three days to monitor the trend. It’s worth noting that after about 11 weeks, HCG levels naturally decline even in healthy pregnancies, so timing matters when interpreting these results.^[1]

Once a viable intrauterine pregnancy is confirmed, the typical recommendation is rest and symptom management at home. Many healthcare providers advise taking acetaminophen for cramping pain, as it is considered safe during pregnancy. It’s important not to take multiple pain medicines at the same time unless specifically instructed by a doctor, since many over-the-counter medications contain acetaminophen, and too much can be harmful. Pregnant individuals are often advised to avoid sexual intercourse until their provider says it is safe, and to get plenty of rest over the following days.^[3]

Good nutrition is also emphasized as part of standard care. A balanced diet rich in iron and vitamin C is recommended. Foods high in iron include red meat, shellfish, eggs, beans, and leafy green vegetables, while citrus fruits, tomatoes, and broccoli provide vitamin C. Some providers may recommend iron pills or a multivitamin. It is especially important to avoid alcohol, tobacco, illegal drugs, and smoking, as these can increase the risk of pregnancy complications. Normal activities can usually be resumed if the person feels well enough, but heavy exercise should be avoided until cleared by the healthcare provider.^[3]

An important part of standard care involves knowing when to seek emergency help. Severe vaginal bleeding, dizziness or feeling faint, new or worsening belly or pelvic pain, fever, or foul-smelling vaginal discharge are all signs that require immediate medical attention. In such cases, calling emergency services or going to the nearest emergency department is advised.^[3]

Progestogen therapy under investigation

While expectant management with close monitoring remains the mainstay of care, researchers have explored whether hormone treatments might help reduce the risk of miscarriage in women experiencing threatened miscarriage. Progestogens are medications that mimic the activity of progesterone, a hormone naturally produced during pregnancy. Progesterone plays vital roles in maintaining pregnancy: it helps prepare the lining of the uterus, suppresses uterine contractions that could lead to miscarriage, and helps regulate the mother’s immune system so that it does not reject the pregnancy. Because of these functions, it seems logical that supplementing with progestogens might help support a threatened pregnancy.^[6]

Several clinical trials have tested whether progestogens can reduce the risk of miscarriage in women with threatened miscarriage. A comprehensive review published by the Cochrane collaboration examined seven randomized controlled trials involving 696 patients from various countries, though none were from North America. These trials tested both oral and vaginal forms of progestogen. The review found that women who received progestogen treatment had a lower risk of miscarriage compared to those who received placebo or no treatment. Specifically, for every 10 women treated with progestogens, one additional miscarriage was prevented.^[6]

The trials included in this review were considered to provide moderate-quality evidence for the main outcome of whether the pregnancy continued or ended in miscarriage. Three of the trials tested oral progestogens, and four tested vaginal progesterone. When the results were combined, oral progestogens appeared to be more effective than vaginal forms, though both routes were studied. Two of the three oral trials used a medication called dydrogesterone, which is not available in the United States. The third trial used oral micronized progesterone at a dose of 400 milligrams daily for four weeks, starting when threatened miscarriage was diagnosed and continuing even if the bleeding stopped.^[6]

Importantly, the use of progestogens did not cause significant harms to the mother or baby. When compared to placebo, there were no differences in rates of pregnancy-induced high blood pressure, bleeding before delivery, stillbirth, low birth weight, or respiratory distress in newborns. There also appeared to be no significant differences in preterm birth or birth defects, though the evidence for these outcomes was of lower quality and more research is needed. The side effects of progestogens are usually mild and may include breast tenderness, bloating, and headache. However, these medications should be used cautiously in people with heart disease or liver problems.^[6]

Despite these promising findings, it’s important to note that progestogen therapy for threatened miscarriage is not yet universally recommended as standard care. Clinical guidelines are still being developed, and healthcare providers may offer this treatment on a case-by-case basis. The decision to use progestogens depends on individual circumstances, and patients should discuss the potential benefits and risks with their healthcare provider.^[6]

Understanding what causes threatened miscarriage

There is no single cause of threatened miscarriage. Many different factors can contribute to a person experiencing bleeding and cramping in early pregnancy. One of the most common underlying reasons, when a miscarriage does occur, is chromosomal problems with the developing baby. These are genetic abnormalities that happen randomly during the earliest stages of development and are not caused by anything the mother did or did not do.^[1]

Other factors that may increase the risk of threatened miscarriage include having had a previous miscarriage, using alcohol or drugs or being exposed to certain chemicals early in pregnancy, having obesity, being older than 40 during pregnancy, smoking cigarettes or vaping, problems with the placenta, experiencing trauma or injury, and having vaginal or uterine infections. It’s crucial to understand that stress, exercise, and sexual activity do not cause miscarriage. Many people blame themselves when they experience bleeding during pregnancy, but in most cases, there is nothing they could have done to prevent it. If a miscarriage does happen, it usually means the pregnancy was not developing normally due to factors beyond anyone’s control.^[1][3]

Diagnosing and monitoring the condition

Proper diagnosis is essential when a pregnant person presents with vaginal bleeding or cramping. The first step is to establish whether the pregnancy is located inside the uterus, since bleeding and pain can also be signs of an ectopic pregnancy—a potentially life-threatening condition where the pregnancy develops outside the uterus, often in a fallopian tube. Once an intrauterine pregnancy is confirmed, the next step is to determine whether the pregnancy is viable.^[2]

This is accomplished through a combination of physical examination and imaging. During a pelvic exam, the healthcare provider checks whether the cervix—the opening of the uterus—is closed. In a threatened miscarriage, the cervix remains closed, and no pregnancy tissue has been passed. If the cervix is open or tissue has been passed, it may indicate that a miscarriage is already in progress. Ultrasound is the most important tool for assessing the pregnancy. A vaginal or pelvic ultrasound can detect the baby’s heartbeat and confirm that the pregnancy is developing inside the uterus. If fetal cardiac activity is seen, it is a reassuring sign that the pregnancy is viable.^[2]

Sometimes, especially very early in pregnancy, the baby’s heartbeat may not yet be visible on ultrasound. In such cases, providers may order follow-up ultrasounds over the following days or weeks to monitor the pregnancy’s development. Serial blood tests measuring HCG and progesterone levels help track whether the pregnancy is progressing normally. If HCG levels are rising appropriately and the cervix remains closed, there is reason for optimism that the pregnancy will continue.^[1]

How long does it last and what happens next

The duration of a threatened miscarriage varies widely from person to person. Some people experience bleeding and cramping for just a few days, while others may have symptoms that continue for several weeks. The exact timing and intensity of symptoms differ based on individual circumstances. During this period, close monitoring by a healthcare provider is important to ensure that the pregnancy is progressing and that no complications develop.^[1]

It’s natural to feel worried or upset about the possibility of losing a pregnancy. This is a stressful and uncertain time, and emotional support is just as important as medical care. Many people find it helpful to talk with their healthcare provider, a counselor, or trusted friends and family members about their feelings. Follow-up care is a key part of treatment and safety. Attending all scheduled appointments and staying in communication with the healthcare team helps ensure the best possible outcome.^[3]

Most common treatment methods

• Expectant management (watchful waiting)
  • Close clinical monitoring with regular follow-up appointments
  • Pelvic examination to check if the cervix is closed
  • Ultrasound to monitor fetal heartbeat and pregnancy location
  • Serial blood tests to track HCG and progesterone levels every two to three days
• Symptom management and self-care
  • Acetaminophen for cramping pain (avoid multiple pain medications at once)
  • Rest and avoidance of heavy exercise until cleared by provider
  • Pelvic rest (avoiding sexual intercourse until provider approval)
  • Balanced diet rich in iron (red meat, shellfish, eggs, beans, leafy greens) and vitamin C (citrus fruits, tomatoes, broccoli)
  • Avoidance of alcohol, tobacco, illegal drugs, and smoking
• Progestogen therapy (under investigation)
  • Oral progestogens such as micronized progesterone (400 mg daily for four weeks) or dydrogesterone (not available in the United States)
  • Vaginal progesterone formulations
  • Moderate-quality evidence suggests progestogens reduce miscarriage risk (number needed to treat = 10)
  • Generally safe with mild side effects (breast tenderness, bloating, headache)
  • Used cautiously in people with cardiovascular disease or liver problems