What are some factors that make a pregnancy high risk?

Several factors can make a pregnancy high risk, including existing health conditions, the mother’s age, lifestyle, and health issues that happen before or during pregnancy.

This page provides some possible factors that could create a high-risk pregnancy situation. This list is not meant to be all-inclusive, and each pregnancy is different, so the specific risks for one pregnancy may not be risks for another. Women who have any questions about their pregnancy should talk to a healthcare provider.

For the latest information on COVID-19 and pregnancy, visit CDC at https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/pregnant-people.html.

  • High blood pressure. Even though high blood pressure can be risky for the mother and fetus, most women with slightly high blood pressure and no other diseases have healthy pregnancies and healthy deliveries because they get their blood pressure under control before pregnancy. Uncontrolled high blood pressure, however, can damage the mother’s kidneys and increase the risk for low birth weight or preeclampsia.1 It is very important for women to have their blood pressure checked at every prenatal visit so that healthcare providers can detect any changes and make decisions about treatment.
  • Polycystic ovary syndrome (PCOS). Women with PCOS have higher rates of pregnancy loss before 20 weeks of pregnancy, diabetes during pregnancy (gestational diabetes), preeclampsia, and cesarean section.2
  • Diabetes. It is important for women with diabetes to manage their blood sugar levels both before getting pregnant and throughout pregnancy. During the first few weeks of pregnancy, often before a woman even knows she is pregnant, high blood sugar levels can cause congenital anomalies. Even women whose diabetes is well under control may have changes in their metabolism during pregnancy that require extra care or treatment to promote a healthy birth.3 Babies of mothers with diabetes tend to be large and are likely to have low blood sugar soon after birth. That is another reason for women with diabetes to keep tight control of their blood sugar.
  • Kidney disease. Women with mild kidney disease often have healthy pregnancies. But kidney disease can cause difficulties getting and staying pregnant as well as problems during pregnancy, including preterm delivery, low birth weight, and preeclampsia. Nearly one-fifth of women who develop preeclampsia early in pregnancy are found to have undiagnosed kidney disease.4 Pregnant women with kidney disease require additional treatments, changes in diet and medication, and frequent visits to their healthcare provider.5,6
  • Autoimmune disease. Conditions such as lupus and multiple sclerosis can increase a women’s risk for problems during pregnancy and delivery. For example, women with lupus are at increased risk for preterm birth and stillbirth. Some women may find that their symptoms improve during pregnancy, while others have flare-ups and other challenges. Certain medicines to treat autoimmune diseases may be harmful to the fetus, meaning a woman with an autoimmune disease will need to work closely with a healthcare provider throughout pregnancy.7
  • Thyroid disease. The thyroid is a small gland in the neck that makes hormones that help control heart rate and blood pressure. Uncontrolled thyroid disease, such as an overactive or underactive thyroid, can cause problems for the fetus, such as heart failure, poor weight gain, and brain development problems. Thyroid problems are usually treatable with medicine or surgery.8 However, a recent NICHD-supported study found that treating mildly low thyroid function during pregnancy did not improve outcomes for mothers or their babies.
  • Obesity. Being obese before pregnancy is associated with a number of risks for poor pregnancy outcomes. For example, obesity increases a woman’s chance of developing diabetes during pregnancy, which can contribute to difficult births.9 Obesity can also cause a fetus to be larger than normal, making the birth process more difficult. NICHD research also found that obesity increases the risk for sleep apnea and disordered sleep breathing during pregnancy. Obesity before pregnancy is associated with an increased risk of structural problems with the baby’s heart. There can also be problems if overweight or obese women gain too much weight during pregnancy. NICHD research has shown that an integrated approach can help obese women to limit their weight gain during pregnancy, leading to better pregnancy outcomes. The Institute of Medicine recommends that overweight women gain no more than 15–25 pounds during pregnancy and that women with obesity gain no more than 11–20 pounds.10
  • HIV/AIDS. HIV can pass to a fetus during pregnancy, labor and delivery, and breastfeeding. Fortunately, there are effective treatments that can reduce and prevent the spread of HIV from mother to fetus or child. Medications for the mother and for the infant, as well as surgical delivery of the baby before the “water breaks” and feeding formula instead of breastfeeding, can prevent mother-to-child transmission and have led to a dramatic decrease in transmission—to less than 1% in the United States and other developed countries.11
  • Zika infection. Although scientists and healthcare providers have known about Zika for decades, the link between Zika infection during pregnancy and pregnancy risks and congenital anomalies has only recently come to light. NICHD-supported research has shown that infants born to mothers who were infected with Zika just before and during pregnancy were at higher risk for different problems with the brain and nervous system. The most noticeable is microcephaly, a condition in which the head is smaller than normal. Zika infection during pregnancy can also increase the woman’s risk for pregnancy loss and stillbirth. Researchers are still just learning the possible mechanisms of Zika’s effects on pregnancy.

  • Young age. Pregnant teens are more likely to develop pregnancy-related high blood pressure and anemia (lack of healthy red blood cells) and to go through preterm (early) labor and delivery than women who are older. Teens are also more likely to not know they have a sexually transmitted infection (STI). Some STIs can cause problems with the pregnancy or for the baby.12 Teens may be less likely to get prenatal care or to keep prenatal appointments. Prenatal care is important because it allows a healthcare provider to evaluate, identify, and treat risks, such as counseling teens not to take certain medications during pregnancy, sometimes before these risks become problems.13
  • First-time pregnancy after age 35. Most older first-time mothers have normal pregnancies, but research shows that older women are at higher risk for certain problems than younger women,14 including:
    • Pregnancy-related high blood pressure (called gestational hypertension) and diabetes (called gestational diabetes)15
    • Pregnancy loss16
    • Ectopic pregnancy (when the embryo attaches itself outside the uterus), a condition that can be life-threatening17
    • Cesarean (surgical) delivery
    • Delivery complications, such as excessive bleeding
    • Prolonged labor (lasting more than 20 hours)
    • Labor that does not advance
    • Genetic disorders, such as Down syndrome, in the baby15

  • Alcohol use. Drinking alcohol during pregnancy can increase the baby’s risk for fetal alcohol spectrum disorders (FASDs), sudden infant death syndrome, and other problems. FASDs are a variety of effects on the fetus that result from the mother’s drinking alcohol during pregnancy. The effects range from mild to severe, and they include intellectual and developmental disabilities; behavior problems; abnormal facial features; and disorders of the heart, kidneys, bones, and hearing. FASDs are completely preventable: If a woman does not drink alcohol while she is pregnant, her child will not have an FASD.18

    Women who drink also are more likely to have a miscarriage or stillbirth. Currently, research shows that there is no safe amount of alcohol to drink while pregnant. According to one study supported by NIH, infants can suffer long-term developmental problems even with low levels of prenatal alcohol exposure.19
  • Tobacco use. Smoking during pregnancy puts the fetus at risk for preterm birth, certain congenital anomalies, and sudden infant death syndrome (SIDS). One study showed that smoking doubled or even tripled the risk of stillbirth, or fetal death after 20 weeks of pregnancy.20 Research has also found that smoking during pregnancy leads to changes in an infant’s immune system.21 Secondhand smoke also puts a woman and her developing fetus at increased risk for health problems.22
  • Drug use. Research shows that smoking marijuana and taking drugs during pregnancy can also harm the fetus and affect infant health. One study showed that smoking marijuana and using illegal drugs doubled the risk of stillbirth.20 Research also shows that smoking marijuana during pregnancy can interfere with normal brain development in the fetus, possibly causing long-term problems.23 For more information, visit https://www.drugabuse.gov/publications/research-reports/substance-use-in-women/substance-use-while-pregnant-breastfeeding.

  • Multiple gestation. Pregnancy with twins, triplets, or more fetuses, called multiple gestation, increases the risk of infants being born prematurely (before 37 weeks of pregnancy). Both giving birth after age 30 and taking fertility drugs have been linked 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 single infants. If infants are born prematurely, they are more likely to have difficulty breathing.24
  • Gestational diabetes. Gestational diabetes occurs when a woman who didn’t have diabetes before develops diabetes when she is pregnant. Gestational diabetes can cause problems for both mother and fetus, including preterm labor and delivery, and high blood pressure. It also increases the risk that a woman and her baby will develop type 2 diabetes later in life. Many women with gestational diabetes have healthy pregnancies because they work with a healthcare provider to manage their condition.
  • Preeclampsia and eclampsia. Preeclampsia is a sudden increase in a pregnant woman’s blood pressure after the 20th week of pregnancy. It can affect the mother’s kidneys, liver, and brain. The condition can be fatal for both the mother and the fetus or cause long-term health problems. Eclampsia is a more severe form of preeclampsia that includes seizures and possibly coma.
  • Previous preterm birth. Women who went into labor or who had their baby early (before 37 weeks of pregnancy) with a previous pregnancy are at higher risk for preterm labor and birth with their current pregnancy. Healthcare providers will want to monitor women at high risk for preterm labor and birth in case treatment is needed. NICHD research has shown that, among women at high risk for preterm labor and birth because of a previous preterm birth, giving progesterone can help delay birth.25 In addition, women who become pregnant within 12 months after their latest delivery may be at increased risk for preterm birth.26 Women who have recently given birth may want to talk with a healthcare provider about contraception to help delay the next pregnancy.
  • Congenital anomalies or genetic conditions in the fetus. In some cases, healthcare providers can detect health problems in the fetus during pregnancy. Depending on the nature of the problems, the pregnancy may be considered high risk because treatments are needed while the fetus is still in the womb or immediately after birth. For example, if certain forms of spina bifida are detected in the fetus, the problems can be repaired before birth. Certain heart problems that are common among infants with Down syndrome need to be corrected with surgery immediately after birth. Knowing a fetus has Down syndrome before birth can help healthcare providers and parents be prepared to give treatment right away.


  1. American College of Obstetricians and Gynecologists. (2018). FAQs: Preeclampsia and high blood pressure during pregnancy. Retrieved October 31, 2018, from https://www.acog.org/Patients/FAQs/Preeclampsia-and-High-Blood-Pressure-During-Pregnancy 
  2. Office on Women's Health. (2016). Polycystic ovary syndrome (PCOS) fact sheet. Retrieved February 6, 2017, from http://www.womenshealth.gov/publications/our-publications/fact-sheet/polycystic-ovary-syndrome.html (PDF 126 KB)
  3. National Institute of Diabetes and Digestive and Kidney Diseases. (2017). Pregnancy if you have diabetes. Retrieved February 6, 2017, from https://www.niddk.nih.gov/health-information/diabetes/diabetes-pregnancy
  4. Williams, D., & Davison, J. (2008). Chronic kidney disease in pregnancy. BMJ, 336(7637), 211–215. Retrieved February 8, 2017, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2213870/
  5. National Kidney Foundation. (2016). Pregnancy and kidney disease. Retrieved February 6, 2017, from http://www.kidney.org/atoz/content/pregnancy.cfm 
  6. Kendrick, J., Sharma, S., Holmen, J., Palit, S., Nuccio, E., & Chonchol, M. (2015). Kidney disease and maternal and fetal outcomes in pregnancy. American Journal of Kidney Diseases, 66(1), 55–59. Retrieved March 8, 2017, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4485539/
  7. Office on Women's Health. (2012). Autoimmune diseases fact sheet. Retrieved February 6, 2017, from http://womenshealth.gov/publications/our-publications/fact-sheet/autoimmune-diseases.html
  8. Office on Women's Health. (2017). Thyroid disease fact sheet. Retrieved February 6, 2017, from https://www.womenshealth.gov/a-z-topics/thyroid-disease
  9. Vesco, K. K., Sharma, A. J., Dietz, P. M., Rizzo, J. H., Callaghan, W. M., England, L., et al. (2011). Newborn size among obese women with weight gain outside the Institute of Medicine recommendation. Obstetrics & Gynecology, 117, 812–818.
  10. Institute of Medicine. (2009). Weight gain during pregnancy. Retrieved on February 6, 2017, 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  (PDF 716 KB)
  11. American College of Obstetricians and Gynecologists. (2012). FAQs: HIV and pregnancy. Retrieved February 6, 2017, from http://www.acog.org/~/media/For%20Patients/faq113.pdf?dmc=1&ts=20120730T1640322605  (PDF 279 KB)
  12. American College of Obstetricians and Gynecologists. (2015). FAQ 103: Having a baby (especially for teens). Retrieved February 6, 2017, from http://www.acog.org/Patients/FAQs/Having-a-Baby-Especially-for-Teens 
  13. American Academy of Pediatrics. (2015). Teenage pregnancy. Retrieved February 6, 2017, from http://www.healthychildren.org/English/ages-stages/teen/dating-sex/pages/Teenage-Pregnancy.aspx 
  14. Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). (2007). Older mothers more likely than younger mothers to deliver by caesarean. Retrieved February 6, 2017, from http://www.nichd.nih.gov/news/releases/pages/caesarean_release_030807.aspx
  15. Gill, S. K., Broussard, C., Devine, O., Green, R. F., Rasmussen, S. A., Reefhuis, J.; The National Birth Defects Prevention Study. (2012). Association between maternal age and birth defects of unknown etiology: United States, 1997–2007. Birth Defects Research. Part A, Clinical and Molecular Teratology, 94(12), 1010–1018. Retrieved February 20, 2017, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4532312/
  16. Grande, M., Borrell, A., Garcia-Posada, R., Borobio, V., Muñoz, M., Creus, M., et al. (2012). The effect of maternal age on chromosomal anomaly rate and spectrum in recurrent miscarriage. Human Reproduction, 27(10), 3109–3117. Retrieved February 8, 2017, from https://www.ncbi.nlm.nih.gov/pubmed/22888165
  17. Sivalingam, V. N., Duncan, W. C., Kirk, E., Shephard, L. A., & Horne, A. W. (2011). Diagnosis and management of ectopic pregnancy. Journal of Family Planning and Reproductive Health Care, 37(4), 231–240. Retrieved February 20, 2017, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3213855/
  18. Centers for Disease Control and Prevention. (2018). Fetal alcohol spectrum disorders: Alcohol use in pregnancy. Retrieved October 1, 2018, from http://www.cdc.gov/ncbddd/fasd/alcohol-use.html
  19. Eckstrand, K. L., Ding, Z., Dodge, N. C., Cowan, R. L., Jacobson, J. L., Jacobson, S. W., et al. (2012). Persistent dose-dependent changes in brain structure in young adults with low-to-moderate alcohol exposure in utero. Alcoholism: Clinical and Experimental Research, 36(11), 1892–1902. Retrieved March 19, 2018, from https://www.ncbi.nlm.nih.gov/pubmed/22594302
  20. NICHD. (2013). Tobacco, drug use in pregnancy can double risk of stillbirth. Retrieved March 19, 2018, from https://www.nichd.nih.gov/news/releases/Pages/121113-stillbirth-drug-use.aspx
  21. NICHD. (2016). Cigarette smoking during pregnancy linked to changes in baby's immune system. Retrieved March 19, 2018, from https://www.nichd.nih.gov/news/releases/122316-smoking-pregnancy
  22. Centers for Disease Control and Prevention. (n.d.). Pregnant? Don't smoke. Retrieved February 6, 2017, from http://www.cdc.gov/Features/PregnantDontSmoke/
  23. NICHD. (2016). Prenatal exposure to marijuana may disrupt fetal brain development, mouse study suggests. Retrieved March 19, 2018, from https://www.nichd.nih.gov/news/releases/Pages/031516-prenatal-exposure-marijuana.aspx
  24. MedlinePlus. (2015). Twins, triplets, multiple births. Retrieved February 6, 2017, from https://medlineplus.gov/twinstripletsmultiplebirths.html#cat1
  25. American College of Obstetricians and Gynecologists. (2016). FAQs: Preterm (premature) labor and birth. Retrieved April 25, 2018, from https://www.acog.org/Patients/FAQs/Preterm-Labor-and-Birth 
  26. Howard, E. J., Harville, E., Kissinger, P., & Xiong, X. (2013). The association between short interpregnancy interval and preterm birth in Louisiana: A comparison of methods. Maternal and Child Health Journal, 17(5), 933–939.
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