Pregnancy Complications

Safe motherhood begins BEFORE a woman becomes pregnant and includes proper nutrition, a healthy lifestyle, and good control of any chronic medical conditions like high blood pressure or diabetes. Once a woman becomes pregnant, safe motherhood continues with appropriate prenatal care and early identification and treatment of problems. 

Pregnancy symptoms and complications can range from mild and annoying discomforts to severe, sometimes life-threatening illnesses. It can be difficult to determine which symptoms are normal and which are abnormal. Problems during pregnancy may include physical and psychological conditions that negatively affect the health of the mother or the baby. These problems result from, or are made worse by being pregnant. Many conditions are mild, and do not progress; however, when some conditions do progress, they may place both the woman or her baby in danger. To read more about the range of pregnancy complications that can occur in a managed care organization, refer to Maternal morbidity rates in a managed care population. (Obstet Gynecol. 2008;111:1089–1095).

CDC's Division of Reproductive Health conducts research to better understand  pregnancy-related problems with the aim of making pregnancy healthier, preventing or managing complications, and reducing poor pregnancy outcomes, including death—the most extreme adverse outcome. There are approximately 6 million pregnancies each year in the United States. Small advances in preventing pregnancy-related complications can improve the quality of life for thousands of pregnant women. Evidence-based public health prevention will occur only when we have improved sources of maternal health data and improved methods for measuring and studying the data. Highlights of some of our research data follow. 

Gestational Weight Gain

Obesity during pregnancy is now a common condition affecting approximately 1 of 5 pregnant women. CDC research has shown that obesity during pregnancy is associated with an increased use of health care services, including—

• Greater use of inpatient and outpatient health care services.
• Increased length of hospital stays for delivery.
• Greater use of physician services.
• Less use of services by nurse practitioners and physician assistants during prenatal visits. (Association between obesity during pregnancy and increased use of health care. N Engl J Med. 2008;358:1444–1453).

To address the 2009 Institute of Medicine (IOM) Research Recommendations on Gestational Weight Gain, CDC has developed the following projects to examine:

• The impact of weight gain on postpartum weight retention among obese women. (Excessive gestational weight gain and postpartum weight retention among obese women. Obstet Gynecol. 2009;114:1069–1075).
• Gestational weight gain and birth size among obese women and effect modification by obesity severity. This study found that 57% of women gained excess weight (more than 20 pounds). Gains of more than 20 pounds did not reduce the chances of babies being small for their gestational age, but did increase the chances of babies being large for their gestational age. More efforts are needed to help obese women achieve an ideal weight gain of no more than 11–20 pounds during pregnancy (Newborn size among obese women with weight gain outside the 2009 Institute of Medicine Recommendation. Obstet Gynecol. 2011;117:812–818).
• Other illnesses that may explain the association between low gestational weight gain and preterm birth.
• Patterns of weight gain and preterm birth.

Gestational Diabetes Mellitus

In the United States, almost all doctors now screen for GDM during prenatal visits. It offers an opportunity to assess the woman’s risk for type 2 diabetes. Both the American Congress of Obstetricians and Gynecologists and the American Diabetes Association recommend postpartum diabetes testing for all women who developed diabetes while pregnant; however, only about 50% of women who need the test actually get it. The postpartum period may be an especially hard time for women who had GDM to return to their provider for testing and to include exercise and a healthy diet into their schedules. New mothers are recovering from delivery, caring for a newborn and often other children, and some are returning to work.

To address this public health problem, CDC researchers developed several collaborative projects targeted particularly for postpartum women. One of CDC’s priorities is to work with health care systems, providers, professional groups, and women to increase and improve, 1) postpartum glucose testing, 2) postpartum counseling about a healthy diet and weight management, and 3) follow-up and referral of women who developed diabetes while pregnant.

Diabetes prevention strategies shown to have been effective in other populations have not been tested in postpartum women with a recent history of GDM. The Diabetes Prevention Program (DPP) was a large randomized trial among adults with glucose intolerance and impaired fasting glucose. Results identified intervention strategies that reduced the incidence of type 2 diabetes. Intervention strategies included lifestyle modification (i.e., a healthy diet, exercise, and weight management) or medication. The lifestyle intervention was more effective than the medication. (Reduction in the incidence of type 2 Diabetes with lifestyle intervention or metformin. N Engl J Med. 2002;346(6):393–403).

CDC is working with university investigators to develop a modified version of the Diabetes Prevention Program intervention tailored specifically to meet the needs of postpartum women. Findings will be used to develop recommendations for implementing a diabetes prevention strategy for women with a recent history of GDM. Additionally, CDC and a large managed care organization conducted a study that revealed that postpartum glucose screening among women who had GDM was very low. These findings were used to develop an improved process for postpartum glucose testing. This included staff education sessions, revised diabetes patient care rules, electronic order entry tools, and an electronic reminder system for women who had not completed postpartum glucose testing within 3 months of delivery. As a result, these strategies led to increased screening, enhanced counseling, and better follow-up of affected women (Postpartum screening for diabetes after a gestational diabetes mellitus–affected pregnancy. Obstet Gynecol. 2008;112:868–874).

Pregnancy-related Deaths

Pregnancy-related deaths fell significantly in the United States during the 20th century, reaching their lowest point in 1987. This historic decline was due largely to medical and technological advances. In addition, interest and concern at the local, state, and federal levels led to developing systems for identifying, reviewing, and analyzing pregnancy-related deaths. These systems have been instrumental in helping researchers determine causes of deaths, identify gaps in health services, disseminate findings, and propose recommendations to prevent pregnancy-related mortality.

In 1987, CDC’s Division of Reproductive Health started to conduct national surveillance of pregnancy-related mortality through the Pregnancy Mortality Surveillance System. This surveillance system detects deaths that occur during pregnancy or within a year of pregnancy termination. (Learn more about data collection for CDC’s Pregnancy Mortality Surveillance System.) CDC scientists review the data, analyze cause of deaths and factors associated with these deaths, and publish the data to inform state and national prevention strategies to address pregnancy-related mortality. Although the risk of dying from pregnancy complications is low among pregnant women, some women may be at a higher risk than others. Variability in the risk of death by race, ethnicity, and age indicates that more can be done to understand and reduce pregnancy-related deaths [Beyond the numbers: Reviewing maternal deaths and complications to make pregnancy safer (World Health Organization)].

Whether the actual risk of a woman dying from pregnancy complications has increased is unclear. Many studies show that an increasing number of pregnant women in the United States have chronic health conditions such as hypertension, diabetes, and obesity. These conditions may put a pregnant woman at higher risk of adverse outcomes.