10 Things to Know About Miscarriages

Although most miscarriages are completely outside of one’s control—they’re commonly caused by chromosomal problems—there are some lifestyle and physiological issues that could raise the risk. It’s useful for hopeful parents to keep a few things in mind before and during pregnancy to help maximize the chances of a successful pregnancy.

Althea O’Shaughnessy, MD, a fertility specialist with Conceptions Reproductive Associates of Colorado, offers insights on what might cause a miscarriage, plus other factors that may affect your ability to sustain a pregnancy.

It’s important to know that miscarriages are common. The American College of Obstetricians and Gynecologists (ACOG) reports that about 10 percent of all known pregnancies end with an early pregnancy loss. That figure does not take into account miscarriages that occur before someone knows they’re pregnant. One study published in the New England Journal of Medicine followed 221 women who were trying to conceive and found that among those women, 31 percent had miscarriages.

“I’m sure if you talk to five women, one out of those five are going to have had a miscarriage at one point in their lives or they’ll know someone who did,” says Dr. O’Shaughnessy. “And that's because most miscarriages are caused by chromosomal abnormalities which occur randomly.”

The most common reason for early pregnancy loss is a problem with chromosomal division. In fact, ACOG explains that 60 percent of pregnancy losses occur because the embryo—the fertilized egg that has divided into cells and implanted itself into the wall of the uterus—receives an irregular number of chromosomes.

Chromosomes are structures inside cells that carry genes. Typically, the sperm has 23 chromosomes and the egg has 23. But if there is an abnormal number, developmental issues can occur. Miscarriage happens when a chromosome abnormality is so damaging that further development is not possible.

People who experience miscarriage may blame themselves, but it’s very unlikely that anything you did contributed to the pregnancy loss. ACOG says that work, exercise, sex, and prior birth control use do not cause miscarriage. It’s also unlikely that stress contributes to the chance of miscarriage. Falls are generally not a concern early in a pregnancy, but they do become worrisome after 14 weeks, when the uterus is no longer protected by the pelvis. If you suspect that you are pregnant, speak with a healthcare provider (HCP) about the lifestyle habits you can establish to increase your chances of having a healthy pregnancy.

Certain health problems may increase the risk of miscarriages and recurrent miscarriages. They include:

• Uterine abnormalities such as a septate uterus, or a uterus that is separated into two sections with a wall of tissue in the middle
• Fibroids and polyps, benign growths within the uterus that disturb the uterine cavity   
• Asherman syndrome, a condition that involves scar tissue inside the uterine cavity
• Thyroid conditions like hypothyroidism and hyperthyroidism
• Blood clotting issues like antiphospholipid antibody syndrome, a condition in which the immune system attacks normal proteins in your blood
• Polycystic ovary syndrome, a condition triggered by an imbalance of reproductive hormones
• Diabetes, especially in people whose blood sugar is not well-controlled.

Blood tests can often detect blood clotting issues, genetic causes, and thyroid conditions. And standard infertility screening tests like the hysterosalpingography (a special X-ray of the uterus and fallopian tubes) or an ultrasound can paint a clearer picture of your reproductive organs to help identify anything abnormal. It’s worth noting, though, that around 50 percent of the time, no cause can be identified for repeated miscarriages.

Treatments often depend upon the type and severity of the issue, miscarriage history, and your plans for becoming pregnant. Certain medications, including some antibiotics and antifungal medications, have been associated with a higher rate of miscarriage. If you’re taking any medications or need a new medication while you are pregnant, make sure to talk with your HCP about how this may affect your pregnancy.

Just as the risk for fertility issues increases as you get older, your risk of miscarriage and a decline in egg quality also rise. And although abnormal sperm issues might contribute, too, most of the problems have to do with one’s eggs, says O’Shaughnessy.

One-third of people who get pregnant after 40 experience early pregnancy loss. “While a woman ages, her eggs are sitting around in a suspended state,” says O’Shaughnessy. “This can affect the way in which chromosomes separate and can cause chromosomal abnormalities in the eggs themselves, otherwise known as ‘an error in meiosis.’”

As a fertility specialist, O’Shaughnessy performs assisted reproductive procedures such as in vitro fertilization (IVF). What she’s discovered during egg retrievals is that people in their 20s may have up to 20 percent of their eggs test as abnormal. For a person over 40, meanwhile, it’s common to see as many as 80 percent that are abnormal.

If you are 35 or older, especially if you’ve been trying to conceive for more than six months or you’ve had multiple miscarriages, talk with an HCP about having an evaluation. Blood tests can show current hormone levels and help identify any conditions that may predispose you to miscarriage. Your HCP can answer questions about whether or not you should keep trying to get pregnant naturally, and if so, for how long. Depending on your circumstances, you may want to discuss fertility treatment options, as well.

In addition to health conditions, infertility and miscarriage can be affected by certain lifestyle habits. “Some research suggests that smoking can increase the risk of miscarriage, and alcohol use during the first trimester may slightly increase the risk of early pregnancy loss, too, but the research is not clear,” says O’Shaughnessy.

“Smoking affects blood flow to the ovaries,” O’Shaughnessy says. “When we do IVF on women who smoke, we find that the quality of their eggs and their embryos are definitely impacted.”

Experts do not recommend consuming any amount of alcohol during pregnancy or while trying to conceive. Drinking can cause fetal alcohol spectrum disorders, which are associated with a variety of health problems for your baby like learning disabilities, vision and hearing problems, and low body weight. Drinking during pregnancy can also increase the risk of miscarriage.

Other substances like marijuana, cocaine, heroin, and methamphetamine can increase the risk of poor pregnancy outcomes, including miscarriage. These drugs pass to the fetus through the placenta, and the exposure to these drugs can not only lead to miscarriage, but also birth defects, infant withdrawal symptoms, and placental abruption, when the placenta separates from the uterine lining.

O’Shaughnessy says to lower your risk, it’s best to avoid using drugs or alcohol during pregnancy. Talk with your HCP before becoming pregnant if addiction is an issue. If you do become pregnant, tell them right away so they can recommend a treatment plan. You can also reach out to:

• Alcoholics Anonymous to find a recovery center near you
• 1-800-QUIT-NOW for free smoking cessation counseling, a quit plan, and other resources to help you quit
• Substance Abuse and Mental Health Services Administration to locate an addiction program that’s right for you

It’s no surprise that one’s overall health plays a role in miscarriage risk. Obesity—indicated by a body mass index (BMI) of 30 or more—can increase the risk, as can being underweight or having other conditions like high blood pressure.

A 2016 study published in The Lancet Diabetes & Endocrinology found that women with obesity are not only more likely to have a miscarriage than women who are not obese, but also to deliver prematurely and have newborns with certain health conditions. People with obesity are also more likely to have recurrent miscarriages. Miscarriage risk is higher in those with obesity who are undergoing assisted reproductive therapy like IVF, as well. Obesity can cause hormone fluctuations, which can interrupt embryonic development.

Those with elevated blood pressure may also have an increased risk of miscarriage. One 2018 study published in the journal Hypertension observed 1,228 mostly overweight or obese women who had had at least one miscarriage but were trying to conceive again. Risk of pregnancy loss was found to increase with increased blood pressure, suggesting that elevated blood pressure is associated with miscarriage.

Whether obesity, hypertension, or both are factors in your life, experts recommend taking steps to manage your blood pressure and weight. The American Heart Association recommends getting regular exercise and following the Dietary Approaches to Stop Hypertension (DASH) or Mediterranean-style diets. These eating plans focus on fruits, vegetables, low-fat dairy, whole grains, fish and poultry, healthy fats like nuts and vegetable oils, as well as lower amounts of added sugars, salt, and red meat.

If there are no signs of infection, you’ll likely have the choice to wait and allow the tissue to pass naturally. You may pass a miscarriage naturally or with medication prescribed by your HCP that can help your body pass the tissue and placenta more quickly. The process is noninvasive, but you should be prepared for pain and bleeding that can last up to two weeks in some cases.

If there is a complication, such as a septic miscarriage (where there is an incomplete miscarriage that leads to an infection), your HCP may recommend a dilation and curettage (D&C), a surgical procedure to remove the tissue, since such conditions can be life-threatening if left untreated. It’s likely you’ll receive anesthesia for the surgery.

Your HCP can provide you with information about the risks and benefits so that you can reach a decision that’s right for your situation. If there is an incomplete miscarriage without infection, heavy bleeding or other problems, you may be able to choose the route you’d like to go.

O’Shaughnessy recommends that you not make all of the decisions at your first appointment, unless it’s necessary to avoid medical issues like infections. “Once your doctor has confirmed you’re having a miscarriage, go home and take some time to cry, grieve, talk with your partner and wrap your head around what’s going on as much as you can, given the circumstances,” she says. Meet with your HCP on a different day to make a decision about how you’d like to proceed.

Whether your pregnancy lasted 5 weeks or 12 weeks, the aftermath of a miscarriage, whether you let the tissue pass naturally or through surgery, may be hard. It’s important that you take the time you may need to process your emotions and express feelings that may come up, while recognizing that the outcome is usually out of your control. Keep in mind that you may have trouble sleeping, working and eating, and you may experience emotional ups and downs that include both happiness and sadness.

“There’s no right or wrong way to handle a miscarriage,” says O’Shaughnessy. But using your resources as the days, weeks, and months pass may provide some comfort.

Often, talking with someone who’s been through what you’ve been through—whether it’s someone you know or someone you meet during the experience—can provide comfort. Sharing stories, albeit difficult ones, may enable you to understand what’s happened, and eventually, how to move on.

Resources like UnspokenGrief and M.E.N.D can connect you with others who’ve experienced miscarriage and provide you with stories about fertility after pregnancy loss. The March of Dimes can also send you a bereavement kit with additional resources if they may be helpful to you.