Complications are the last thing any parent-to-be wants to think about. But even though most pregnancies go according to plan, it’s important to know what the unexpected looks like, just in case it happens. Below, we explain the symptoms, causes and treatments for a variety of pregnancy complications, as well as risk factors that can make them more likely.

Note that although these are some of the more common complications that can happen during pregnancy, that doesn’t mean you’ll experience them. They’re still generally unlikely. Plus, keeping up with your prenatal appointments and following your care provider’s recommendations will minimize your risk.

Risk factors for developing pregnancy complications

Certain health and lifestyle factors can make complications more likely. When these factors are present, a pregnancy is referred to as high risk. Having a high-risk pregnancy doesn’t mean you’re guaranteed to have complications, but it means that you may need to schedule more prenatal appointments and tests. This way your care team can keep a closer eye on you and your baby’s health in case you need additional care, and they may also refer you to a maternal-fetal medicine doctor for more detailed ultrasounds to evaluate your baby.

So, what makes a pregnancy high risk? Your doctor or midwife may deem your pregnancy high risk based on a range of factors, including:


Being of advanced maternal age (35 years old or older) at the time of your pregnancy is a risk factor. Of course, 35 isn’t a hard limit. It’s still very likely that you will have a healthy pregnancy in your late 30s and 40s. But complications related to high blood pressure, gestational diabetes and genetic conditions can increase with age.

As you get older, your ovaries also become more likely to release more than one egg at a time. This means that you have a greater likelihood of having multiples.

Body mass index (BMI)

As BMI increases during pregnancy, blood pressure, blood sugar and inflammation do, too. Because of this, being overweight (having a BMI of 25-29.9) or obese (having a BMI of 30 or higher) during pregnancy increases the risk of high blood pressure and gestational diabetes, among other complications. Being overweight or obese also tends to increase the length of labor, and makes it harder to monitor the baby, which can mean needing a cesarean delivery (C-section). The baby is also at a greater risk of birth defects.

Similarly, being underweight (having a BMI below 18.5) can also increase the risk of certain pregnancy complications. Being underweight means that parent and baby may not be getting enough energy and nutrients from food, which makes miscarriage more likely, as well as premature birth or low birth weight for the baby.

It’s important to note that the risks associated with being under- or overweight are also associated with losing or gaining weight too quickly during pregnancy. If necessary, your care provider will recommend ways to reach a healthy weight safely through diet and physical activity.

Preexisting health conditions

Chronic conditions that you had before you became pregnant, like being under- or overweight, might affect your pregnancy. Other examples include:

  • Asthma
  • Autoimmune diseases
  • Diabetes
  • Heart conditions
  • High blood pressure
  • Mental health conditions

How a condition affects your pregnancy will depend on how well you manage it before and after you become pregnant. The good news is that your care team can help you with any conditions you may have.

Lifestyle choices

Consuming alcohol, tobacco, marijuana or other drugs during pregnancy can increase the risk of stillbirth and preterm birth. These substances also increase a baby’s risk of having a low birth weight, as well as physical and neurological (mental) development issues.

It’s especially important to limit alcohol during the first few weeks of pregnancy, when your baby’s organs are developing. The safest approach is to stop alcohol consumption as soon as you start trying to conceive, in case you don’t notice any early signs of pregnancy. But generally, you don’t have to worry if you had a glass of wine or two before you knew you were pregnant. The real concern is regular, excessive drinking.

As for tobacco, marijuana and other drugs, it’s recommended that you quit as far ahead of becoming pregnant as possible.

Pregnant with multiples

Being pregnant with two or more babies increases the risk of a wide variety of complications. With identical twins that share a placenta, it’s possible for blood to be unequally diverted through the placenta, leaving one twin with too much and the other with too little. This is known as twin-to-twin transfusion syndrome (TTTS).

Multiples also make umbilical cord, amniotic fluid and other growth restriction issues more likely. Additional complications include preterm labor and delivery, anemia, high blood pressure, gestational diabetes and postpartum bleeding.

The most common pregnancy complications

While you can do a lot to keep your risk of complications low, there will always be some degree of risk. Being able to recognize symptoms will help you know when to ask for help and allow you to get treatment before a potential issue could become more serious. Below is a list of pregnancy complications, along with their potential effects and symptoms.


Anemia during pregnancy is when there aren’t enough healthy red blood cells to move oxygen around the body. The lack of oxygen can affect vital organs, and the heart has to work harder to make up for it. Symptoms of anemia may include:

Iron deficiency is the most common cause of anemia during pregnancy, because the body needs to make extra blood for itself and the baby. Iron-deficient anemia is easily treated with iron supplements, which support red blood cell production.

Gestational diabetes

Overly high blood sugar that develops for the first time during pregnancy is referred to as gestational diabetes. Uncontrolled diabetes can lead to complications like the baby growing too large and high blood pressure. It can also increase the likelihood of needing a C-section or intravenous (IV) treatments following delivery.

Generally, gestational diabetes is detected through regular blood sugar tests at prenatal appointments. But you may also notice symptoms like extreme hunger, thirst or fatigue.

Gestational diabetes is very manageable. In addition to getting checked regularly at your prenatal appointments, physical activity and eating a healthy pregnancy diet can do a lot to keep it under control. In some cases, a medication is needed to keep blood sugar in a healthy range.

High blood pressure

High blood pressure or hypertension is when the force of blood against the walls of the arteries is abnormally high. This makes it harder for blood to flow and can put stress on the internal organs. Some people develop high blood pressure during pregnancy, typically after 20 weeks. This is referred to as gestational hypertension and usually goes away after birth.

In some cases, high blood pressure can restrict the flow of nutrients and oxygen to the baby, and can lead to complications like restricted growth of the baby, premature birth and preeclampsia. Your care team will check your blood pressure when you come in for prenatal appointments. Treatment involves taking steps to manage your blood pressure, sometimes with medicine.


During pregnancy, the combination of high blood pressure and symptoms of organ complications (generally in the liver or kidneys) is referred to as preeclampsia. Preeclampsia usually develops after 20 weeks of pregnancy. In rare cases, it can develop earlier in pregnancy, or after the baby has been delivered. If preeclampsia isn’t controlled, it can lead to organ damage or eclampsia, which involves seizures. Symptoms of preeclampsia include:

  • Swelling in the hands and face
  • Stomach pain
  • Headaches
  • Dizziness
  • Vision changes (blurriness, sensitivity, etc.)

Once preeclampsia has been diagnosed, the best way to protect against further complications may be for the baby to be delivered as soon as possible, depending on how developed they are. If they’re near term (around 37 weeks), a care provider may recommend inducing labor or performing an unplanned C-section. If the baby is premature, the parent will be monitored closely and may be given medicine to control blood pressure, as well as steroid injections to support baby’s lung development. In the most serious cases, hospitalization is typically recommended and anti-seizure medication may be given. Occasionally, the baby has to be delivered immediately, regardless of how developed it is.

Hyperemesis gravidarum

It’s normal to experience morning sickness during pregnancy, but hyperemesis gravidarum (HG) is more serious. HG involves severe nausea that can lead to dehydration and weight loss if it goes untreated. Other symptoms include:

  • Nausea that doesn’t go away
  • Frequent vomiting
  • Reduced appetite
  • Feeling faint

Mild cases of HG can be treated by switching to dry, bland foods, taking antacids and resting. A care provider may also prescribe anti-nausea medicine. In more serious cases, hospitalization may be required so that nutrients and fluids can be provided through an intravenous tube (IV).


Growing a baby requires your body to suppress its immune system. This creates a greater risk of infection, which can lead to other complications. Infections during pregnancy can also be passed to the baby, so it’s doubly important to take precautions.

Your care team will make sure that your immunization record is up to date, and test you for certain infection-causing bacteria and viruses throughout your pregnancy. It’s also important to get tested for sexually transmitted infections (STIs), as they can be present without symptoms. People are also at greater risk of urinary tract infections (UTI) during pregnancy because as the uterus continues to grow, it can block urine from draining from the bladder.

Most infections are treatable, especially if they’re treated early. But some medicines that are used to treat infections aren’t safe to take while pregnant. Talk to your care provider if you have questions about infections during pregnancy.

Mental health conditions

Between hormonal changes and new stressors, mood swings are common and perfectly normal during pregnancy. But in some cases, it can take some outside help to manage mental health. Symptoms of conditions like depression and anxiety may include long-lasting, frequent or severe episodes of:

  • Feeling sadness, guilt, worthlessness or hopelessness
  • Struggling with the actions of your daily life (eating, sleeping, bathing, etc.)
  • Obsession or worry about your baby or things related to them
  • Racing or panicked thoughts

Talk to your care provider right away if you’re struggling with your mental health. They can prescribe therapies, medicines and other treatments to help you feel like yourself again. Getting help is the best thing you can do for both yourself and your baby.

Placental issues

Two common complications that can occur with the placenta include:

Placenta previa

Placenta previa is when the placenta covers the cervix, making vaginal delivery unsafe for the baby. The main symptom is bright red, painless vaginal bleeding. Placenta previa is generally diagnosed by an ultrasound exam when evaluating your baby’s anatomy.

Depending on when in the pregnancy placenta previa is diagnosed and if there is any bleeding, treatment may involve reducing activity or hospitalization. The baby may also need to be delivered by C-section.

Placental abruption

Placental abruption is when the placenta separates from the uterine wall before delivery, which can decrease oxygen and nutrient flow to the baby. It may be diagnosed by using a physical exam and an ultrasound. Symptoms tend to include:

  • Vaginal bleeding
  • Abdominal pain or cramping
  • Tenderness in the belly or uterine area

Treatment depends on how much of the placenta separates from the uterine wall. If it’s a minor to moderate amount, reduced activity or hospitalization may be recommended until bleeding stops. If there’s concern for the baby’s well-being, it may require immediate medical attention and early delivery.

Preterm labor

Labor is considered preterm if it takes place before 37 weeks of pregnancy. Preterm labor can lead to premature birth, and babies who are born prematurely are at a higher risk for physical and neurological issues like low birth weight and learning disabilities. Symptoms include the usual signs that labor is starting, including:

  • Increasingly intense contractions that happen at regular intervals
  • Consistent discomfort or pain in your belly and lower back
  • Vaginal discharge of pink or red mucus (“bloody show”)
  • Watery discharge that comes out in a gush or a slow trickle

In some cases, medication may be used to temporarily stop preterm labor from progressing. This can allow time for the use of other medications that can support development and help prevent complications for your baby. If you believe that you’re experiencing symptoms of preterm labor, call your care team right away.

When to call your care provider

The sooner symptoms of potential complications can be evaluated and treated, the better. Your care team will be looking for symptoms at your prenatal appointments. But in between appointments, you should immediately call your care provider if you ever notice:

  • Dizziness, fever or chills
  • Discomfort when urinating
  • Discomfort or cramping in your lower belly
  • Issues with your vision
  • Severe or long-lasting headaches
  • Sudden swelling in your face or hands
  • Thoughts of harming either your baby or yourself
  • Vaginal bleeding or leakage
  • Vomiting or long-lasting nausea
  • Less movement from your baby than usual (after 28 weeks)

HealthPartners’ 24/7 OB-GYN nurse line is also available to answer questions or concerns you have about any pregnancy symptoms you’re experiencing.

Get the pregnancy support you need

The possibility of complications may be scary, but your doctor or midwife and the rest of your care team are committed to making sure you and your growing baby are healthy and safe. The checkups, tests and everything else that happens as part of your prenatal appointment schedule are done to catch and treat symptoms of potential complications as soon as possible.

And if you have a high-risk pregnancy, you may be referred to a maternal-fetal medicine doctor (or perinatologist). These doctors specialize in high-risk and complicated pregnancies, and manage care alongside your doctor or midwife. Not all care systems have maternal-fetal medicine doctors, so make sure to explore all of your options.