Diagnosing Recurrent Miscarriage

NYU Langone doctors are specialists in recurrent miscarriage, in which you have had two or more pregnancies in a row that end before the 20th week. The condition can be caused by chromosomal problems, which are passed from one or both parents; conditions such as diabetes or fibroids, which are noncancerous growths on the uterus; immune system problems; hormonal imbalances; or congenital abnormalities of the uterus.

About 1 percent of women who experience miscarriage have more than one in a row. In 50 to 75 percent of women who have recurrent miscarriages, doctors can’t pinpoint the cause. 

Women over age 35 are at higher risk than younger women for miscarriage. That’s because older women are more likely to have eggs with chromosomal irregularities, as well as a higher risk of health conditions that can affect pregnancy.

Signs of miscarriage include vaginal bleeding accompanied by abdominal pain, back pain, severe cramps, fever, or passing blood clots or gray tissue from the vagina.

To diagnose recurrent miscarriage, a specialist at NYU Langone’s Fertility Center takes a medical history, performs a physical exam, and orders certain tests. 

Blood Tests

Your NYU Langone doctor may draw blood to test your levels of progesterone, a hormone that thickens the lining of the uterus and nurtures embryo development; thyroid hormones; and certain proteins that can affect the ability to maintain a pregnancy. You may also be tested for pelvic inflammatory disease, a sexually transmitted disease that can raise your risk of miscarriage, or for antiphospholipid syndrome, a rare autoimmune disease in which blood clots impede blood flow. 

Ultrasound

An ultrasound—which uses sound waves to create images of organs and other structures in the body—enables a doctor to detect fibroids or polyps, uterine growths that can cause infertility or miscarriage. During this in-office test, the doctor uses a transvaginal ultrasound, in which a wand called a transducer is inserted into the vagina, to produce detailed images of the reproductive organs.  

A test called FemVue involves injecting a saltwater solution and air bubbles into the uterus and fallopian tubes and viewing them using ultrasound.

Genetic Screening

Most miscarriages are due to aneuploidy, which means the embryo has an irregular number of chromosomes. A small percentage of recurrent miscarriages are caused by a chromosomal rearrangement called a translocation, in which a small piece of DNA from one chromosome moves to another, or by an inversion, in which a small piece of DNA is inserted in reverse order on the chromosome. 

These genetic variations—which can be present in either the man or the woman—result in chromosomally unbalanced eggs or sperm. After conception, the embryos cannot develop, resulting in miscarriage. 

A doctor may recommend that you and your partner have karyotype tests. This blood test helps doctors determine if you have the correct number and configuration of chromosomes. 

Hormone Tests

Because the risk for recurrent miscarriage increases with age, women ages 35 and older may have a blood test that checks for the level of follicle-stimulating hormone, or FSH. Released by the pituitary gland in the brain, FSH stimulates the ovaries to produce ova, or eggs, which mature inside chambers called follicles. The number of follicles available decreases as a woman ages, contributing to age-related infertility

High FSH levels may mean the ovaries lack eggs suitable for pregnancy. Low FSH levels may indicate severe stress, which in turn could contribute to miscarriage.

Doctors may also order an anti-Mullerian hormone (AMH) test to gauge ovarian reserve, which is the number and quality of eggs available for fertilization. 

Hysterogram

Also called a hysterosalpingogram, or HSG, this test enables your doctor to view the reproductive organs for anatomical problems and conditions, such as fibroids, that can lead to miscarriage. It can also reveal scar tissue caused by endometriosis or infection that can block the fallopian tubes, the passageways where eggs move from the ovaries to the uterus. 

To perform the test, your doctor injects a dye into the uterus through a small catheter, which is a hollow tube. An X-ray produces images of the uterus and fallopian tubes. The test takes about 10 minutes. An HSG can cause temporary discomfort similar to menstrual cramps, so your doctor may recommend an over-the-counter pain reliever.

Hysteroscopy

If HSG or FemVue, a test that doesn’t require X-ray or contrast dye exposure, reveal a condition in the uterine cavity that can affect pregnancy, you may undergo a hysteroscopy, which allows the doctor to perform surgical techniques to correct the problem. These can include fibroids, large polyps, uterine adhesions (scar tissue), or a uterine condition that may have been present since birth. 

In this procedure, performed in the hospital, your doctor uses a long, thin, flexible scope with a camera on the end to examine the uterus for any abnormalities. It can be performed with local, regional, or general anesthesia, and it takes up to 45 minutes to complete. Because a hysteroscopy can cause cramping and soreness, your doctor may prescribe pain medications.

Endometrial Biopsy

This procedure, which may be performed at the same time as a hysteroscopy, can help your doctor determine whether the uterus is capable of maintaining a pregnancy. Your doctor removes a small piece of tissue from the lining of the uterus to test it for irregular cells that can indicate infections, fibroids, or polyps. 

The biopsy may cause cramping, which can be minimized by taking an over-the-counter pain medication up to an hour before the test. This test is performed only in rare circumstances.