Every pregnancy carries its risks. But good prenatal care and support can help you minimize those risks. Factors like age and overall health status can increase your chances of experiencing complications during pregnancy.

Reproductive abnormalities

Structural problems in the uterus or cervix can heighten the risk of difficulties like miscarriage, an abnormally positioned fetus, and difficult labor.

These problems also increase the risk of a cesarean delivery.

Women under age 20

Women under the age of 20 have a significantly higher risk of serious medical complications related to pregnancy than those over 20. Teenage mothers are more likely to:

Some risk factors connected to young age include the following.

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  • Underdeveloped pelvis. Young women’s bodies are still growing and changing. An underdeveloped pelvis can lead to difficulties during childbirth.
  • Nutritional deficiencies. Young women are more likely to have poor eating habits. Nutritional deficiency can lead to extra strain on the body that causes more complications for both the mother and child.
  • High blood pressure. Developing high blood pressure in pregnancy can trigger premature labor. This can lead to premature or underweight babies who require specialized care to survive.

Women over age 35

As you age, your chances of conceiving begin to decline. An older woman who becomes pregnant is also less likely to have a problem-free pregnancy.

Common issues include the following:

Underlying conditions

Older women are more likely to have conditions like high blood pressure, diabetes, or cardiovascular disease that can complicate pregnancy. When these conditions aren’t well controlled, they can contribute to miscarriage, poor fetal growth, and birth defects.

Chromosomal problems

A woman over 35 has a higher risk of having a child with birth defects due to chromosomal issues.

Down syndrome is the most common birth defect related to chromosomes. It causes varying degrees of intellectual disability and physical abnormalities. Prenatal screening and tests can help determine the likelihood of chromosomal complications.


According to the Mayo Clinic, the risk of miscarriage increases for women who are over the age of 35.

While the reason for this is unclear, it’s believed to be due to an increased risk of preexisting medical conditions combined with a decrease in the quality of a woman’s eggs as she ages.

One study even found that paternal age can have an effect on miscarriage — if the father is over 40 and the mother is over 35, the risk for miscarriage is much greater than if just the woman is over 35.

Other complications

Women over 35 are more likely to have complications commonly associated with pregnancy regardless of age, including:


Being either overweight or underweight can lead to complications during pregnancy.


Women who are obese are at a higher risk than normal-weight women of having babies with certain birth defects, including:

Obese women are also more likely to be diagnosed with gestational diabetes during the pregnancy or to have high blood pressure. This can lead to a smaller than expected baby as well as increase the risk for preeclampsia.


Women who weigh less than 100 pounds are more likely to deliver prematurely or give birth to an underweight baby.


People with both type 1 and type 2 diabetes may experience complications during pregnancy. Poor control of diabetes can increase the chances of birth defects in the baby and can cause health concerns for the mother.

If you haven’t had diabetes before the pregnancy, you may be diagnosed with diabetic symptoms during pregnancy. This is called gestational diabetes.

If you’re diagnosed with gestational diabetes, you should talk with your doctor about the specific recommendations to control blood sugar. Dietary changes will be recommended. You’ll also be advised to monitor your blood sugar levels.

You may have to take insulin to control your blood sugar levels. Women who have gestational diabetes are at much higher risk for developing diabetes after their pregnancy is over. Testing for diabetes once your pregnancy is over is recommended.

Sexually transmitted infections (STIs)

You should be screened for STIs during your first prenatal visit. Women who have an STI are very likely to transmit it to their baby. Depending on the infection, a baby born to a woman with an STI is at a higher risk for:

The STIs that are commonly screened for during prenatal visits include:

Not only is there a risk that these infections can be passed from mother to child, but they can also cause serious complications during pregnancy. For example, an untreated gonorrhea infection can increase the risk of miscarriage, premature birth, and low birth weight.

Pregnant women who have HIV can transmit the virus to their child during pregnancy, childbirth, or breastfeeding. In order to prevent this, mothers with HIV should take medications for treating HIV.

Babies born to mothers living with HIV may receive such medication for several weeks after birth.

HIV-negative mothers with an HIV-positive partner should speak to their doctor about taking pre-exposure prophylaxis (PrEP) to reduce their chances of getting HIV.

Preexisting medical conditions

Some preexisting medical conditions can make you more susceptible to complications during pregnancy. Some examples include:

High blood pressure

Pregnant women with chronic high blood pressure are at an increased risk for a low birth weight infant, preterm delivery, kidney damage, and preeclampsia during pregnancy.

Polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a hormonal disorder that can cause irregular periods and your ovaries to not function properly. Pregnant women with PCOS have a higher risk of miscarriage, premature delivery, gestational diabetes, and preeclampsia.

Autoimmune disease

Examples of autoimmune diseases include conditions like multiple sclerosis (MS) and lupus.

Women with an autoimmune disease may be at a risk for premature delivery or stillbirth. Additionally, some medication that’s used to treat autoimmune disease may harm the developing fetus.

Kidney disease

Women with kidney disease have an increased risk of miscarriage. Additionally, they should work with their doctor throughout their pregnancy to monitor their diet and medications.

Thyroid disease

Hyperthyroidism (overactive thyroid) or hypothyroidism (underactive thyroid) that isn’t controlled can lead to heart failure or poor weight gain in the fetus as well as birth defects.


Asthma that’s not controlled can lead to an increased risk of poor fetal weight gain and premature delivery.

Uterine fibroids

While uterine fibroids can be relatively common, they can cause miscarriage and premature delivery in rare cases. A cesarean delivery may be required when a fibroid is blocking the birth canal.

Multiple pregnancies

If you’ve had five or more previous pregnancies, you’re more susceptible to abnormally quick labor and accompanying excessive blood loss during future labors.

Multiple-birth pregnancies

Complications arise in multiple-birth pregnancies because more than one baby is growing in the womb. Because of the limited amount of space and the additional strain multiple fetuses put on a woman, these babies are more likely to arrive prematurely.

Many pregnancy complications, like high blood pressure and diabetes, are more common in multiple pregnancies.

Previous complications with pregnancy

If you’ve had complications in a previous pregnancy, you may be more likely to have the same complication in subsequent pregnancies. Examples include things like a prior preterm delivery, a prior stillbirth, or prior incidence of genetic or chromosomal problems.


While every pregnancy has risks, some factors such as age, weight, and preexisting medical conditions can lead to an increased risk of complications.

If you fall into any of these groups, you should be sure to speak to your doctor about it. That way, you can get the prenatal care and assistance that you need while reducing any risks.