Miscarriage: Causes, Signs, and What to Expect

Learn why miscarriage happens, its warning signs, and what to do once it occurs.

miscarriage sign lculig/shutterstock.com

Miscarriage: It’s a topic you never want to think about, let alone discuss, especially if you’re pregnant. Sadly, it’s very common. According to the American College of Obstetricians and Gynecologists (ACOG), about 15 to 20 percent of pregnancies end in miscarriage. Here we explain what a miscarriage is, what causes it, the signs of miscarriage, and more.

What is a miscarriage?

Miscarriage or spontaneous abortion, which is defined as the spontaneous loss of a pregnancy in the first 20 weeks, is the most common type of pregnancy loss. Statistics collected by ACOG reflect only the number of miscarriages in confirmed pregnancies; experts believe the actual number is much higher. “We estimate that about 30 to 40 percent of all conceptions result in a pregnancy loss,” says.Helain Landy, M.D., Professor and Chair of the Department of Obstetrics and Gynecology at Georgetown University Hospital. “This is because many women miscarry before they know they’re pregnant, or before it has been confirmed by a health-care provider.”

What Causes Miscarriage

What causes one?

Although it’s common for a woman to wonder if she has miscarried because of something she did or didn’t do, it’s important not to blame yourself. Miscarriage is not caused by moderate exercise, sex, or a small daily cup of coffee. The most common cause, according to American Pregnancy Association (APA), is a chance chromosomal or genetic abnormality in the embryo.

Other risk factors include:

    • Drug use
    • Smoking
    • Excess drinking
    • Listeria, a bacteria that may be present in undercooked meats, raw eggs, and unpasteurized dairy products
    • Maternal trauma, such as a car accident
    • Hormonal or structural abnormalities in the mother (such as low progesterone levels or uterine fibroids)
    • Advanced maternal age (over 35)
    • Infections such as Lyme disease or Fifth disease
    • Chronic illnesses such as uncontrolled diabetes, lupus, or thyroid disease

      What are some miscarriage symptoms?

      Spotting in early pregnancy is fairly common, but it should never be considered normal, and it always warrants a call to your ob-gyn, Dr. Landy says. Although the presence of spotting does not always indicate a miscarriage, it is a sign that something abnormal may be going on in the pregnancy, she adds. “Even if everything looks normal, the fact that the patient’s had spotting will be kept in the back of our minds throughout her pregnancy.”

      Some women do not experience any symptoms of miscarriage at all; however, possible signs besides bleeding include:

        • Mild to severe cramps
        • Back pain
        • Loss of pregnancy symptoms, such as nausea or vomiting
        • White-pink mucus
        • Passing tissue or clot-like material

          Is it possible to stop a miscarriage if symptoms are caught early enough?

          Sadly, there’s no way to stop a miscarriage from happening once it’s started. According to Dr. Landy, however, it is vital to be seen by your doctor and treated to prevent hemorrhaging and/or infection.

          What is a chemical pregnancy?

          A chemical pregnancy occurs when an egg is fertilized but never implants in the uterus. The fertilized egg signals the body to begin making hCG (human ghorionic gonadotropin, sometimes commonly referred to as the pregnancy hormone), which can result in an early positive pregnancy test–even three to four days before a woman’s first missed period. Unfortunately, because the egg fails to develop and implant properly, no clinical evidence (such as a gestational sac or placenta) would be found on an ultrasound exam, and the pregnancy is not viable, Dr. Landy says.

          What happens during a miscarriage?

          “Depending on the medical situation, the physical process of losing a pregnancy can vary from person to person,” says Jennifer Jolley, M.D., Assistant Professor of Maternal-Fetal Medicine at the University of Washington in Seattle. Some women will start to have bleeding and cramping, which is caused by contractions that are working to expel the contents of the uterus, and may pass large blood clots and tissue. If it happens rapidly, the miscarriage is usually completed by the body without complications. In the case of a missed miscarriage (when a woman has no symptoms and her body has essentially “missed” the occurrence of fetal demise), a drug can be given to stimulate these contractions.

          “If there is concern the woman could continue to bleed heavily without effective passage of the tissue, the recommendation is usually to proceed with quick evacuation of the uterus–a D&C,” Dr. Jolley explains. “Otherwise, it can become dangerous for the woman.” Dilation and curettage, or D&C as it’s commonly called, is a surgical procedure to complete the miscarriage. Dilation will open the cervix, if it is still closed, and curettage removes the contents of the uterus using a variety of suction and scraping instruments.

          When can I try for another baby after a miscarriage?

          Your doctor or midwife may recommend waiting a certain amount of time before trying to conceive again (if not, feel free to ask), although you may not feel ready to consider trying to conceive another baby for a while, and that’s more than okay.

          What are my chances of miscarriage during my next pregnancy?

          According to the APA, at least 85 percent of women who have suffered a miscarriage will go on to have a healthy, full-term pregnancy the second time around.