Black women are over three times more likely than white women to die of cardiovascular-related pregnancy complications.

Black and American Indian/Alaska Native women are two to three times as likely as white women to die from any pregnancy-related cause.

Hispanic and Black women are more likely than white women to have dangerous complications during delivery.

Experts think many factors help explain the higher risk for some populations.

The disparities might be due in part to differences in insurance coverage and access to care.

But structural racism and other broad social and economic factors — known as social determinants of health — may also be at work. 

In the U.S., risk of pregnancy-related death in women 40 and older is nearly eight times as high as the risk in women 25 and younger.

Women 35 and older are at higher risk of having or developing conditions that make pregnancy complications more likely. Such conditions include chronic high blood pressure, preeclampsia and gestational diabetes.

Increasing age can also amplify racial inequities. For instance, risk of pregnancy-related death in Black women under age 20 is 1.5 times that of white women.

But Black women age 30 to 34 face 4.3 times the risk of white women that age.

Pregnancy-related deaths rose sharply in the U.S. from 1997 to 2012. Some research suggests rising obesity rates could account for nearly a third of the increase.

Obesity is defined as a body mass index of 30 or higher. For a woman 5 feet 4 inches tall, that's a weight of 174 pounds or more.

The heavier you are before you get pregnant, the greater your risk may be of pregnancy complications.

Possible complications include:

• preeclampsia, a high blood pressure disorder
• gestational diabetes, which is diabetes diagnosed during pregnancy
• sleep apnea, which can increase risk for gestational diabetes, preeclampsia and other problems
• stillbirth and cesarean delivery

If your BMI falls in the "overweight" or "obese" range (25 or higher), talk to your health care team about losing weight before getting pregnant.

Also, it's important to keep your weight gain while pregnant within medical guidelines.

Too many extra pounds during a first pregnancy can increase preeclampsia risk, research has found..

Rates of high blood pressure (hypertension) both before and during pregnancy have increased in recent decades.

Hypertension during pregnancy greatly increases risk of heart attack and heart failure.

Women with high blood pressure who get pregnant are also more likely to have pregnancy complications.

If you have high blood pressure and plan to get pregnant, work with your health care team to lower your blood pressure first. Also, some blood pressure drugs are not advised during pregnancy. Ask your team.

Be sure to discuss short-term health risks if you've had fertility treatment.

And tell your team if you are taking any supplements, including high-dose folic acid supplements.

Some evidence suggests that high doses of prenatal supplements might increase risk during pregnancy of a dangerous form of high blood pressure.