How Do Doctors Diagnose Miscarriage and Pregnancy Loss?

Learn How hCG Tests, Ultrasounds, and More Play a Role

Doctor listens for baby's heartbeat with a fetal doppler
Doctor listens for baby's heartbeat with a fetal doppler. Katrina Wittkamp The Image Bank/Getty Images

If you are having miscarriage symptoms (such as vaginal bleeding and abdominal cramping), it's a good idea to call your doctor to get an answer to the question that is likely running through your mind: "Am I having a miscarriage?"

Diagnosing a Miscarriage

In order to figure out whether you're miscarrying, your doctor will probably use some combination hCG blood tests, an ultrasound, fetal heart scanning, and (sometimes) a pelvic exam.

Your doctor will decide which tests are most appropriate for your situation to tell you whether or not you're miscarrying.

Diagnostic tests for miscarriage rarely offer information about the actual cause of the pregnancy loss, but because vaginal bleeding and cramping are not always caused by ​a miscarriage, the tests will help your doctor determine what is happening.

Take a closer look at each test, below.

Quantitative hCG Blood Tests

Human chorionic gonadotropin (hCG) is a hormone that is produced in your body exclusively during pregnancy. It becomes detectable in your blood about a week after ovulation, when the fertilized egg implants in your uterus. In the early weeks of pregnancy, the level of hCG in your blood should double roughly every two to three days. When hCG levels are not increasing appropriately, miscarriage is more likely; miscarriage is almost certain when hCG levels are dropping.

Doctors typically need to see at least two hCG levels taken at least two days apart in order to get any useful information about the pregnancy.

The usefulness of hCG measurements decreases as the pregnancy progresses. In very early pregnancy, the baby is too small to see on an ultrasound, so hCG tests may be the only tool for evaluating how the pregnancy is developing.

By the time a heartbeat and gestational sac are clearly visible on ultrasound, an ultrasound is much more useful for determining whether you're having a miscarriage.

Ultrasound Scans

Ultrasound machines use sound waves through the abdomen or vagina to get a rough image of the gestational sac and developing baby in your uterus. In early pregnancy, until around eight weeks, most practitioners will use transvaginal ultrasound rather than abdominal ultrasound.

Sometimes a single ultrasound in early pregnancy might show results, such as no fetal pole or no fetal heartbeat, that don't match the expectations that were based on your last menstrual period. It could be that you ovulated late in your cycle that month and a follow-up ultrasound will show that the pregnancy is viable but simply not as far along as you and your doctor originally estimated. Even being off by a few days with the estimated date of ovulation can make a difference in what will show up on an early ultrasound.

Fetal Heart Rate Monitors

Fetal heart rate monitors, sometimes called fetal dopplers, are handheld ultrasound devices that detect the sound of your baby’s heartbeat through your abdomen but do not provide any images.

The heartbeat becomes audible on a fetal heart rate monitor somewhere between seven and 12 weeks of gestation, but the exact time varies because of any number of factors (position of the uterus, position of the placenta, etc).

For a woman who is in her late first trimester and has concerns about miscarriage, doctors may use a heart rate monitor as a quick screening tool before ordering further testing; if the heartbeat is audible, miscarriage is much less likely. But not hearing the heartbeat is not a conclusive sign of miscarriage, especially in the first trimester. If you are more than 12 weeks pregnant and your doctor cannot find the baby’s heart rate on the monitor, your doctor may send you for a full ultrasound scan.

Pelvic Exams

Your doctor may include a pelvic exam as a part of the checkup when you go into the office with miscarriage symptoms. This is to check whether your cervix is dilating. A dilated cervix means a greater likelihood of miscarriage, and your doctor will know immediately that you need further testing. Doctors sometimes can look for indicators of an ectopic pregnancy during a pelvic exam, as well (an ectopic pregnancy is when the fertilized egg implants somewhere outside the uterus, such as in the fallopian tubes).

If you are having spotting or light vaginal bleeding and your cervix is not dilating, your doctor may diagnose you with threatened miscarriage and send you home to wait and see if the bleeding stops. Because spotting in early pregnancy is not uncommon, depending on your circumstances, your doctor may want to hold off on ordering further testing unless the bleeding continues.

If you do end up with a diagnosis of miscarriage, it is normal to be upset and to grieve; you may want to look for a support group to help you get through the experience. Know that miscarriage causes are rarely related to anything you did and most losses are random, one-time occurrences. If you have had two or more miscarriages, talk to your medical practitioner about testing for causes of recurrent miscarriages.


A.D.A.M., Inc., "Pregnancy ultrasound." 23 May 2006. A.D.A.M. Healthcare Center.

A.D.A.M., Inc., "HCG blood test - quantitative." 8 Nov. 2006. A.D.A.M. Healthcare Center.

A.D.A.M., Inc., "Transvaginal ultrasound." 24 Jan. 2007. A.D.A.M. Healthcare Center.

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