A threatened miscarriage is a condition that indicates a miscarriage or early pregnancy loss. It might take place before the 20th week of pregnancy.
Some pregnant women have some vaginal bleeding, with or without abdominal cramps, during the first 3 months of pregnancy. When the symptoms indicate a miscarriage is possible, the condition is called a "threatened abortion." (This refers to a naturally occurring event, not due to a medical abortions or surgical abortion.)
Miscarriage is common. Small falls, injuries or stress during the first trimester of pregnancy can cause threatened miscarriage. It occurs in almost one half of all pregnancies. The chance of miscarriage is higher in older women. About one half of women who have bleeding in the first trimester will have a miscarriage.
Symptoms of a threatened miscarriage include:
- Vaginal bleeding during the first 20 weeks of pregnancy (last menstrual period was less than 20 weeks ago). Vaginal bleeding occurs in almost all threatened miscarriages.
- Abdominal cramps may also occur. If abdominal cramps occur in the absence of significant bleeding, consult your health care provider to check for other problems besides threatened miscarriage.
Note: During a miscarriage, low back pain or abdominal pain (dull to sharp, constant to intermittent) can occur. Tissue or clot-like material may pass from the vagina.
Exams and Tests
Your provider may perform an abdominal or vaginal ultrasound to check the baby's development and heartbeat, and the amount of bleeding. A pelvic exam may also be done to check your cervix.
Blood tests done may include:
Apart from controlling the blood loss, you may not need any particular treatment. If you are Rh Negative, then you may be given immune globulin. You may be told to avoid or restrict some activities. Not having sexual intercourse is usually recommended until the warning signs have disappeared.
Most women with a threatened miscarriage go on to have a normal pregnancy.
Women who have had two or more miscarriages in a row are more likely than other women to miscarry again.
Complications may include:
- Anemia from moderate to heavy blood loss, which occasionally requires a blood transfusion.
- The physician will take care to be sure that the symptoms that occur are not due to an ectopic pregnancy, a potentially life-threatening complication.
When to Contact a Medical Professional
If you know you are (or are likely to be) pregnant and you have any symptoms of threatened miscarriage, contact your prenatal provider right away.
Most miscarriages cannot be prevented. The most common cause of a miscarriage is a random genetic abnormality in the developing pregnancy. If you have two or more repeated miscarriages, you should consult a specialist to find out if you have a treatable condition that is causing the miscarriages. Women who get prenatal care have better pregnancy outcomes for themselves and their babies.
A healthy pregnancy is more likely when you avoid things that are harmful to your pregnancy, such as:
- Infectious diseases
- High caffeine intake
- Recreational drugs
Taking a prenatal vitamin or folic acid supplement before becoming pregnant and throughout your pregnancy can lower your chance of miscarriage and improve the chance of delivering a healthy baby.
It is better to treat health problems before you get pregnant than to wait until you are already pregnant. Miscarriages caused by diseases that affect your whole body, such as high blood pressure, are rare. But you can prevent these miscarriages by detecting and treating the disease before becoming pregnant.
Other factors that can increase your risk for miscarriage include:
- Thyroid problems
- Uncontrolled diabetes
Threatened miscarriage; Threatened spontaneous abortion; Abortion - threatened; Threatened abortion; Early pregnancy loss; Spontaneous abortion
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Hobel CJ, Willaims J. Antepartum care: preconception and prenatal care, genetic evaluation and teratology, and antenatal fetal assessment. In: Hacker NF, Gambone JC, Hobel CJ, eds. Hacker & Moore's Essentials of Obstetrics and Gynecology. 6th ed. Philadelphia, PA: Elsevier; 2016:chap 7.
Keyhan S, Muasher L, Muasher SJ. Spontaneous abortion and recurrent pregnancy loss: etiology, diagnosis, treatment. In: Lobo RA, Gershenson DM, Lentz GM, Valea FA, eds. Comprehensive Gynecology. 7th ed. Philadelphia, PA: Elsevier; 2017:chap 16.
Salhi BA, Nagrani S. Acute complications of pregnancy. In: Walls RM, Hockberger RS, Gausche-Hill M, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier; 2018:chap 178.
Review Date 9/25/2018
Updated by: John D. Jacobson, MD, Professor of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda Center for Fertility, Loma Linda, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.