How to Tell if You're at Risk For Miscarriage

5 Things That Commonly Happen During a Miscarriage

A miscarriage is defined as a pregnancy loss before 20 weeks. While statistics vary, the evidence suggests that anywhere from 10% to 20% of known pregnancies will end in miscarriage, usually within the first 13 weeks of gestation.

Miscarriage can happen for any number of reasons including a fetal genetic disorder, abnormalities of the uterus, or trauma. Certain lifestyle factors increase the risk of miscarriage (smoking, drugs) while other don't (moderate exercise, sex).

Knowing when to call a doctor or rush to the emergency room can be tricky since symptoms can often be vague rather than overt. Oftentimes, even the more obvious symptoms turn out to be nothing at all. Irrespective of this, when it comes to the possibility of a miscarriage — or any other complication for that matter — it's best to be safe than sorry.

Here are some of the more typical signs of miscarriage you should know about:

Abnormal Vaginal Bleeding

Riding waves of nausea
Getty Images/PeopleImages

Bleeding during pregnancy can be worrisome to an expectant mother but is more common than you may think. All in all, between 20% and 30% of pregnancies will have some bleeding during the first trimester, of which half will result in a perfectly normal pregnancy. If bleeding occurs, it may be bright red or have a brownish tone.

If bleeding is accompanied by pain, you should definitely see a doctor. Although it is often difficult to distinguish between "normal" pregnancy pains and abnormal ones, you should be checked out just to be safe.

Falling hCG Levels

Syringe being used to take blood sample from patient's arm, close-up.
Peter Cade/The Image Bank/Getty Images

During the first trimester, levels of human chorionic gonadotropin, a pregnancy hormone commonly known as hCG, are supposed to rise during a normal pregnancy. Typically speaking, hCG levels can be expected to double every two to three days in early pregnancy.

When the.hCG levels start to fall, you doctor will most definitely want to monitor this. While it may mean nothing more than your pregnancy date has been miscalculated, it might also suggest a miscarriage or some other pregnancy complication, including an ectopic pregnancy.

Severe or Constant Cramping

Woman with cramps
Ian Hooten/Science Photo Library/Getty Images

If cramping is not accompanied by bleeding, it could be due to dehydration or common physiologic changes such as the uterus growing and stretching in response to the developing fetus.

But cramping can also be a sign of miscarriage. If you're experiencing serious cramping, constant cramping, spotting, or heavy bleeding, call your doctor right away as this could very well be a sign of miscarriage. This is especially true if it is accompanied by lower back pain.

Severe pain one side of the body that is worsening may the sign of an ectopic pregnancy, which should always be treated as a medical emergency.

Call Your Doctor Immediately If You Have:

  • Severe cramping
  • Heavy bleeding
  • Lower back pain
  • Severe pain on one side of the abdomen

Abnormal Ultrasound Readings

Tim Hale/Stone/Getty Images

In many cases, a woman will experience few, if any, symptoms of miscarriage and only learn that something is wrong during a routine ultrasound.

While ultrasounds are usually reliable in diagnosing a miscarriage, it is possible that the ultrasound will not be definitive, especially if the exact date of conception is unclear.

On ultrasound, the lack of fetal growth, an inappropriate size of the gestational sac or fetal pole, or lack of a heartbeat are all signs that a miscarriage either has or will occur. A miscarriage that occurs without symptoms is referred to as a missed miscarriage.

Passing Tissue from the Vagina

Perhaps nothing is as scary as passing clumps of tissue from your vagina during pregnancy. The clumps can often be large and are sometimes accompanied by clots.

Some vaginal discharge is normal during pregnancy and should not be a cause for alarm. It may be caused by a cyst, an infection, or some other condition entirely unrelated to the pregnancy.

However, when the discharge is significant — appearing in grape-like clusters, often with fluid — it could be pregnancy tissue you're looking at. See your doctor even if you're not sure. Even a minor vaginal infection should be looked at and treated during pregnancy.

2 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Breeze C. Early pregnancy bleeding. Aust Fam Physician. 2016;45(5):283-6.

  2. Korevaar TI, Steegers EA, de Rijke YB, et al. Reference ranges and determinants of total hCG levels during pregnancy: the Generation R Study. Eur J Epidemiol. 2015;30(9):1057–1066. doi:10.1007/s10654-015-0039-0

By Robin Elise Weiss, PhD, MPH
Robin Elise Weiss, PhD, MPH is a professor, author, childbirth and postpartum educator, certified doula, and lactation counselor.