What are the factors that put a pregnancy at risk?

The factors that place a pregnancy at risk can be divided into four categories:

Existing Health Conditions

  • High blood pressure. Even though high blood pressure can be risky for mother and fetus, many women with high blood pressure have healthy pregnancies and healthy children. Uncontrolled high blood pressure, however, can lead to damage to the mother's kidneys and increases the risk for low birth weight or preeclampsia.1
  • Polycystic ovary syndrome. Polycystic (pronounced pah-lee-SIS-tik) ovary syndrome (PCOS) is a disorder that can interfere with a woman's ability to get and stay pregnant. PCOS may result in higher rates of miscarriage (the spontaneous loss of the fetus before 20 weeks of pregnancy), gestational diabetes, preeclampsia, and premature delivery.2
  • Diabetes. It is important for women with diabetes to manage their blood sugar levels before getting pregnant. High blood sugar levels can cause birth defects during the first few weeks of pregnancy, often before women even know they are pregnant. Controlling blood sugar levels and taking a multivitamin with 40 micrograms of folic acid every day can help reduce this risk.3
  • Kidney disease. Women with kidney disease often have difficulty getting pregnant, and any pregnancy is at significant risk for miscarriage. Pregnant women with kidney disease require additional treatments, changes in diet and medication, and frequent visits to their health care provider.4
  • Autoimmune disease. Autoimmune diseases include conditions such as lupus and multiple sclerosis. Some autoimmune diseases can increase a women's risk for problems during pregnancy. For example, lupus can increase the risk for preterm birth and stillbirth. Some women may find that their symptoms improve during pregnancy, while others experience flare ups and other challenges. Certain medications to treat autoimmune diseases may be harmful to the fetus as well.5
  • Thyroid disease. Uncontrolled thyroid disease, such as an overactive or underactive thyroid (small gland in the neck that makes hormones that regulate the heart rate and blood pressure) can cause problems for the fetus, such as heart failure, poor weight gain, and birth defects.6
  • Infertility. Several studies have found that women who take drugs that increase the chances of pregnancy are significantly more likely to have pregnancy complications than those who get pregnant without assistance. These complications often involve the placenta (the organ linking the fetus and the mother) and vaginal bleeding.7
  • Obesity. Obesity can make a pregnancy more difficult, increasing a woman's chance of developing diabetes during pregnancy, which can contribute to difficult births.8On the other hand, some women weigh too little for their own health and the health of their growing fetus. In 2009, the Institute of Medicine updated its recommendations on how much weight to gain during pregnancy.9 New recommendations issued by the American College of Obstetricians and Gynecologists suggest that overweight and obese women may be able to gain even less than what is recommended and still have a healthy infant.10
  • HIV/AIDS. HIV/AIDS damages cells of the immune system, making it difficult to fight infections and certain cancers. Women can pass the virus to their fetus during pregnancy; transmission also can occur during labor and giving birth or through breastfeeding. Fortunately, effective treatments exist to reduce the spread of HIV from the mother to her fetus, newborn, or infant. Women with very low viral loads may be able to have a vaginal delivery with a low risk of transmission. An option for pregnant women with higher viral loads (measurement of the amount of active HIV in the blood) is a cesarean delivery, which reduces the risk of passing HIV to the infant during labor and delivery. Early and regular prenatal care is important. Women who take medication to treat their HIV and have a cesarean delivery can reduce the risk of transmission to 2%.11


  • Teen pregnancy. Pregnant teens are more likely to develop high blood pressure and anemia (lack of healthy red blood cells), and go into labor earlier than women who are older. Teens also may be exposed to a sexually transmitted disease or infection that could affect their pregancy.12 Teens may be less likely to get prenatal care or to make ongoing appointments with health care providers during the pregnancy to evaluate risks, ensure they are staying healthy, and understand what medications and drugs they can use.13
  • First-time pregnancy after age 35. Older first-time mothers may have normal pregnancies, but research indicates that these women are at increased risk of having14:
    • A cesarean (pronounced si-ZAIR-ee-uhn) delivery (when the newborn is delivered through a surgical incision in the mother's abdomen)
    • Delivery complications, including excessive bleeding during labor
    • Prolonged labor (lasting more than 20 hours)
    • Labor that does not advance
    • An infant with a genetic disorder, such as Down syndrome.

Lifestyle Factors

  • Alcohol use. Alcohol consumed during pregnancy passes directly to the fetus through the umbilical cord. The Centers for Disease Control and Prevention recommend that women avoid alcoholic beverages during pregnancy or when they are trying to get pregnant.15 During pregnancy, women who drink are more likely to have a miscarriage or stillbirth. Other risks to the fetus include a higher chance of having birth defects and fetal alcohol spectrum disorder (FASD). FASD is the technical name for the group of fetal disorders that have been associated with drinking alcohol during pregnancy. It causes abnormal facial features, short stature and low body weight, hyperactivity disorder, intellectual disabilities, and vision or hearing problems.7
  • Cigarette smoking. Smoking during pregnancy puts the fetus at risk for preterm birth, certain birth defects, and sudden infant death syndrome (SIDS). Secondhand smoke also puts a woman and her developing fetus at increased risk for health problems.15

Conditions of Pregnancy

  • Multiple gestation. Pregnancy with twins, triplets, or more, referred to as a multiple gestation, increases the risk of infants being born prematurely (before 37 weeks of pregnancy). Having infants after age 30 and taking fertility drugs both have been associated with multiple births. Having three or more infants increases the chance that a woman will need to have the infants delivered by cesarean section. Twins and triplets are more likely to be smaller for their size than infants of singleton births. If infants of multiple gestation are born prematurely, they are more likely to have difficulty breathing.16
  • Gestational diabetes. Gestational diabetes, also known as gestational diabetes mellitus, GDM, or diabetes during pregnancy, is diabetes that first develops when a woman is pregnant. Many women can have healthy pregnancies if they manage their diabetes, following a diet and treatment plan from their health care provider. Uncontrolled gestational diabetes increases the risk for preterm labor and delivery, preeclampsia, and high blood pressure.
  • Preeclampsia and eclampsia. Preeclampsia is a syndrome marked by a sudden increase in the blood pressure of a pregnant woman after the 20th week of pregnancy. It can affect the mother's kidneys, liver, and brain. When left untreated, the condition can be fatal for the mother and/or the fetus and result in long-term health problems. Eclampsia is a more severe form of preeclampsia, marked by seizures and coma in the mother.

  1. National Heart, Lung, and Blood Institute. (n.d.). How common are high blood pressure and preeclampsia in pregnancy? Retrieved June 17, 2012, from http://www.nhlbi.nih.gov/health/resources/heart/hbp-pregnancy.htm
  2. Office on Women's Health. (n.d.). Polycystic ovary syndrome (PCOS) fact sheet. Retrieved June 13, 2012, from http://www.womenshealth.gov/publications/our-publications/fact-sheet/polycystic-ovary-syndrome.html
  3. March of Dimes. (2009). Pregnancy complications. Retrieved August 20, 2012, from http://www.marchofdimes.com/pregnancy/complications_diabetes.html External Web Site Policy
  4. National Kidney Foundation. (2012). Pregnancy and Kidney Disease. Retrieved August 20, 2012, from http://www.kidney.org/atoz/content/pregnancy.cfm External Web Site Policy
  5. Office on Women's Health. (2010). Autoimmune diseases fact sheet. Retrieved August 20, 2012, from http://womenshealth.gov/publications/our-publications/fact-sheet/autoimmune-diseases.html
  6. Office on Women's Health. (2010). Pregnancy complications. Retrieved August 20, 2012, from http://www.womenshealth.gov/pregnancy/you-are-pregnant/pregnancy-complications.cfm
  7. Centers for Disease Control and Prevention. (n.d.). Fetal alcohol spectrum disorders: Alcohol use in pregnancy. Retrieved June 13, 2012, from http://www.cdc.gov/ncbddd/fasd/alcohol-use.html
  8. Vesco, K. K., Sharma, A. J., Dietz, P. M., Rizzo, J. H., Callaghan, W. M., et al. (2011). Newborn size among obese women with weight gain outside the Institute of Medicine recommendation. Obstetrics & Gynecology, 117, 812–818.
  9. Institute of Medicine. (2009). Weight Gain During Pregnancy. Retrieved on July 1, 2012, from http://nationalacademies.org/hmd/~/media/Files/Report%20Files/2009/Weight-Gain-During-Pregnancy-Reexamining-the-Guidelines/Report%20Brief%20-%20Weight%20Gain%20During%20Pregnancy.pdf External Web Site Policy (PDF – 716 KB)
  10. American College of Obstetricians and Gynecologists. (2012). Pregnancy and Weight Gain: How Much Is Too Much? Retrieved March 19, 2013, from https://www.acog.org/About_ACOG/News_Room/News_Releases/2012/Pregnancy_and_Weight_Gain
  11. American College of Obstetricians and Gynecologists. (2010). FAQs: HIV and pregnancy. Retrieved July 30, 2012, from http://www.acog.org/~/media/For%20Patients/faq113.pdf?dmc=1&ts=20120730T1640322605 External Web Site Policy (PDF – 279 KB)
  12. MedlinePlus. (n.d.). Teenage pregnancy. Retrieved June 19, 2012, from http://www.nlm.nih.gov/medlineplus/teenagepregnancy.html
  13. American Academy of Pediatrics. (2011). Teenage Pregnancy. Retrieved August 7, 2012, from https://www.healthychildren.org/English/ages-stages/teen/dating-sex/Pages/Teenage-Pregnancy.aspx External Web Site Policy
  14. Eunice Kennedy Shriver National Institute of Child Health & Human Development. (2007). Older Mothers More Likely Than Younger Mothers to Deliver by Caesarean. Retrieved June 13, 2012, from http://www.nichd.nih.gov/news/releases/Pages/caesarean_release_030807.aspx
  15. Centers for Disease Control and Prevention. (n.d.). Pregnant? Don't Smoke. Retrieved June 19, 2012, from http://www.cdc.gov/Features/PregnantDontSmoke/
  16. MedlinePlus. (n.d.) Twins, Triplets, Multiple Births. Retrieved June 13, 2012, from http://www.nlm.nih.gov/medlineplus/twinstripletsmultiplebirths.html#cat1

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