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What are some common complications of pregnancy?

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Some women experience health problems during pregnancy. These complications can involve the mother's health, the fetus, or both. Even women who were healthy before getting pregnant can experience complications. These complications make the pregnancy a high-risk pregnancy.

Getting early and regular prenatal care can help decrease the risk for problems by enabling health care providers to diagnose, treat, or manage conditions before they become serious.

Some common complications of pregnancy include, but are not limited to:


High Blood Pressure

High blood pressure, also called hypertension, occurs when arteries carrying blood from the heart to the body organs are narrowed. This causes pressure to increase in the arteries. In pregnancy, this can make it hard for blood to reach the placenta, which provides nutrients and oxygen to the fetus.1 Reduced blood flow can slow the growth of the fetus and place the mother at greater risk of preterm labor and preeclampsia.2

Women who have high blood pressure before they get pregnant will continue to have to monitor and control it with medications throughout their pregnancy. High blood pressure that develops in pregnancy is called gestational hypertension. According to the Centers for Disease Control and Prevention (CDC), in 2009, the latest year for which information is available, more than 4% of pregnant American women developed this condition during their pregnancy.3 Typically, gestational hypertension occurs during the second half of pregnancy and goes away after delivery.


Gestational Diabetes

Gestational diabetes occurs when a woman who didn't have diabetes before pregnancy develops the condition during pregnancy.

Normally, the body digests parts of your food into a sugar called glucose. Glucose is your body’s main source of energy. After digestion, the glucose moves into your blood to give your body energy.

To get the glucose out of your blood and into the cells of your body, your pancreas makes a hormone called insulin. In gestational diabetes, hormonal changes from pregnancy cause the body to either not make enough insulin, or not use it normally. Instead, the glucose builds up in your blood, causing diabetes, otherwise known as high blood sugar.

Over time, high glucose levels can cause serious health problems, such as heart disease, vision problems, and kidney disease.

Managing gestational diabetes, by following a treatment plan outlined by a health care provider, is the best way to reduce or prevent problems associated with high blood sugar during pregnancy. If not controlled, it can lead to high blood pressure from preeclampsia and having a large infant, which increases the risk for cesarean delivery.2



Preeclampsia is a serious medical condition that can lead to premature delivery. Its cause is unknown, but some women are at an increased risk. Risk factors include4:

  • First pregnancies4
  • Preeclampsia in a previous pregnancy4
  • Existing conditions such as high blood pressure, diabetes, kidney disease, and systemic lupus erythematosus5
  • Being 35 years of age or older5
  • Carrying two or more fetuses5
  • Obesity5
  • Being African American5


Preterm Labor

Preterm labor is labor that begins before 37 weeks of gestation. Any infant born before 37 weeks is at an increased risk for health problems, in most cases because organs such as the lungs and brain finish their development in the final weeks before a full-term delivery (39 to 41 weeks).

Certain conditions increase the risk for preterm labor, including infections, having a shortened cervix (for unknown reasons, in some women the cervix is shorter than normal), or previous preterm births. Sometimes preterm labor can be slowed or stopped by medication.6

Progesterone, a hormone produced naturally during pregnancy, may be used to help prevent preterm birth. A 2003 study led by NICHD researchers found that progesterone supplementation to women at high risk for preterm delivery due to a prior preterm birth reduces the risk of a subsequent preterm birth by one-third.7


Pregnancy Loss/Miscarriage

Miscarriage is the term used to describe a pregnancy loss from natural causes before 20 weeks. According to the American College of Obstetricians and Gynecologists (ACOG), as many as 20% of pregnancies end in miscarriage.8 Signs can include vaginal spotting or bleeding, cramping, or fluid or tissue passing from the vagina. However, bleeding from the vagina does not mean that a miscarriage will happen or is happening.8 Women experiencing this sign at any point in their pregnancy should contact their health care provider.

The loss of pregnancy after the 20th week of gestation is called a stillbirth. In approximately half of all reported cases, health care providers can find no cause for the loss. However, health conditions that can contribute to stillbirth include chromosomal abnormalities, placental problems, poor fetal growth, chronic health issues of the mother, and infection. Read more about health conditions and lifestyle factors that can increase the risk for stillbirth.


Other Complications

Other complications of pregnancy, which are not as common, include the following:

  • Severe, persistent nausea and vomiting. Although having some nausea and vomiting is normal during pregnancy, particularly in the first trimester, some women experience more severe symptoms that last into the third trimester.

    The cause of the more severe form of this problem, known as hyperemesis gravidarum (pronounced HEYE-pur-EM-uh-suhss grav-uh-DAR-uhm), is not known. Women with hyperemesis gravidarum experience nausea that does not go away, weight loss, reduced appetite, dehydration, and feeling faint.9

    Affected women may need to be hospitalized so that they can receive fluids and nutrients. Some women feel better after their 20th week of pregnancy, while others experience the symptoms throughout their pregnancy.1
  • Iron-deficiency anemia. Pregnant women need more iron than normal for the increased amount of blood they produce during pregnancy. Symptoms of a deficiency in iron include feeling tired or faint, experiencing shortness of breath, and becoming pale. Because these symptoms are common for all pregnant women, health care providers check iron levels throughout pregnancy.6 The ACOG recommends 27 milligrams of iron daily (found in most prenatal vitamins) to reduce the risk for iron-deficiency anemia. Some women may need extra iron through iron supplements.10


  1. American College of Obstetricians and Gynecologists. (2011). FAQs: High blood pressure during pregnancy. Retrieved July 30, 2012, from External Web Site Policy [top]
  2. Leeman, L., & Fontaine, P. (2008). Hypertensive Disorders of Pregnancy. American Family Physician, 78, 93–100. [top]
  3. Centers for Disease Control and Prevention. (2011 3). Births: Final Data for 2009. National Vital Statistics Report, 60(1). Retrieved July 31, 2012, from (PDF - 1.84 MB) [top]
  4. Hernandez-Diaz, S., Toh, S., & Cnattinguis, S. (2009). Risk of pre-eclampsia in first and subsequent pregnancies: prospective cohort study. British Medical Journal, 338, b2255. Retrieved July 31, 2012, from [top]
  5. American College of Obstetricians and Gynecologists. (2002). Diagnosis and management of preeclampsia and eclampsia. ACOG Practice Bulletin, 33. Retrieved July 30, 2012, from [top]
  6. Department of Health and Human Services. (2010). Pregnancy. Retrieved July 27, 2012, from [top]
  7. Meis, P. J., Klebanoff, M., Thom E., Dombrowski, M. P., Sibai, B., Moawad, A. H., et al. (2003). Prevention of recurrent preterm delivery by 17 alpha-hydroxyprogesterone caproate. New England Journal of Medicine, 348, 2379–2385 [top]
  8. American College of Obstetricians and Gynecologists. (2011). Early pregnancy loss: miscarriage and molar pregnancy. Retrieved July 30, 2012, from External Web Site Policy (PDF - 281 KB) [top]
  9. National Organization for Rare Diseases. (n.d.). Hyperemis Gravidarum. Retrieved August 1, 2012, from External Web Site Policy [top]
  10. Hassan, S. S., Romero, R., Vidyadhari, D., Fusey, S., Baxter, J. K., Khandelwal, M., et al. (2011). Vaginal progesterone reduces the rate of preterm birth in women with a sonographic short cervix: a multicenter, randomized, double-blind, placebo-controlled trial. Ultrasound in Obstetrics & Gynecology, 38, 18–31. [top]

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