Despite being a developed nation, the United States faces significant challenges in maternal health. While healthcare standards for pregnant and postpartum women in the U.S. are generally higher than in less developed countries, the perinatal and postpartum periods remain vulnerable times for women everywhere. The Centers for Disease Control and Prevention (CDC), through its Division of Reproductive Health (DRH), serves as a central authority on maternal and women’s reproductive health issues. DRH operates the national Pregnancy Mortality Surveillance System and engages in crucial research and public health initiatives focused on maternal mortality and morbidity, substance abuse, and mental health disorders during pregnancy. So, Where Are We today in the landscape of maternal health in the United States? This article delves into the latest insights from the CDC, examining current data, trends, and future directions in these critical areas.
Maternal Mortality in the United States: A Closer Look at Where We Stand
The CDC’s DRH has diligently monitored pregnancy-related mortality since 1987, providing invaluable data on this critical health indicator.1 Through a voluntary system encompassing 52 reporting areas, including all 50 U.S. states, New York City, and the District of Columbia, de-identified death certificates are collected for deaths occurring during or within one year of pregnancy. This comprehensive surveillance, coupled with meticulous review by experienced medical epidemiologists, allows for detailed analysis of causes of death, pregnancy outcomes, and associated factors.
A pregnancy-related death is defined as a death during or within one year of pregnancy resulting from pregnancy complications, a chain of events initiated by pregnancy, or the exacerbation of an unrelated condition due to pregnancy’s physiological effects. This definition ensures a focus on deaths directly or indirectly linked to pregnancy, distinguishing them from pregnancy-associated deaths where pregnancy status is merely coincidental.
FIG. 1.
Trends in pregnancy-related mortality in the United States from 1987 to 2009, showing an increasing mortality ratio over time.
Examining trends in pregnancy-related mortality ratios in the U.S. from 1987 to 2009, as depicted in Figure 1, reveals a concerning upward trajectory. The mortality ratio climbed steadily from 7.2 deaths per 100,000 live births in 1987 to 17.8 deaths per 100,000 live births in 2009. The underlying causes for this increase remain complex and are not fully understood. Improvements in data collection methods, such as computerized data linkages, changes in death cause coding with ICD-10 in 1999, and the addition of a pregnancy checkbox on the 2003 standard U.S. death certificate, have likely enhanced the identification of pregnancy-related deaths.2 Therefore, it is debated whether the actual risk of pregnancy-related death has truly increased or if improved surveillance is revealing a more accurate picture.
It’s also important to consider the increasing prevalence of chronic health conditions among pregnant women in the U.S.3–6 These pre-existing conditions can elevate the risk of adverse pregnancy outcomes, potentially contributing to the observed rise in mortality ratios. Furthermore, the 2009 H1N1 influenza pandemic significantly impacted the 2009 mortality ratio, disproportionately affecting pregnant women.7–9
Comparing U.S. data with other developed countries presents challenges due to variations in mortality definitions and surveillance methods.10 The CDC’s DRH reports deaths within one year postpartum, whereas many developed nations adhere to the WHO/ICD-10 definition of maternal deaths, covering only deaths during pregnancy and within 42 days postpartum. Despite these limitations in direct comparisons, evidence suggests that the risk of dying from pregnancy complications may be higher in the U.S. than in many European countries.10
Significant disparities also exist within the U.S. population. Pregnancy-related mortality ratios are alarmingly 3–4 times higher among Black women compared to White women, as illustrated in Figure 2.11 This disparity is even more pronounced for specific causes like ectopic pregnancy.11,12 Racial and ethnic minorities and foreign-born women also face elevated risks compared to U.S.-born White women.11 While the reasons for these disparities are multifaceted and complex, further research is crucial to identify and address the underlying factors and develop targeted interventions.
FIG. 2.
Race differentials in pregnancy-related mortality in the United States, highlighting the significant disparity between Black and White women from 1987 to 2009.
Analyzing the causes of pregnancy-related deaths reveals shifting trends. Figure 3 shows a decline in traditional causes like hemorrhage, sepsis, and hypertensive disorders, while cardiovascular and other medical conditions have emerged as leading contributors.1,13,14 In the most recent surveillance period (2006–2009), cardiovascular conditions alone accounted for over a third, and together with other medical conditions, half of all pregnancy-related deaths. These trends mirror observations in other developed countries with enhanced maternal death surveillance systems.15 The CDC continues to provide regular updates on the causes of pregnancy-related deaths on its website, www.cdc.gov/reproductivehealth/MaternalInfantHealth/PMSS.html, ensuring ongoing monitoring of this evolving landscape.
FIG. 3.
Causes of pregnancy-related mortality in the United States from 1987 to 2009, indicating a shift from traditional obstetric causes to cardiovascular and other medical conditions.
Severe Maternal Morbidity: Assessing the Current Landscape
Beyond mortality, severe maternal morbidity (SMM) represents a significant burden on women’s health and the healthcare system. Maternal morbidity encompasses a spectrum of physical and psychological conditions arising from or aggravated by pregnancy, impacting a woman’s well-being. While a universally standardized definition of SMM is still evolving, the WHO has proposed definitions and measurement approaches, including the concept of maternal near-miss.16,17
Currently, there is no systematic national data collection for maternal morbidity in the U.S. However, the CDC’s DRH utilizes delivery hospitalization data and a specific SMM algorithm to identify potentially life-threatening maternal conditions or complications.18,19 This algorithm, developed by Callaghan et al., uses ICD-9 codes to capture indicators of organ-system dysfunction, providing a framework for population-based surveillance using administrative data.18 Data is sourced from the Nationwide Inpatient Sample (NIS), the largest all-payer hospital inpatient care database in the United States.21
Trends in SMM in the U.S. from 1998 to 2011, presented in Figure 4, demonstrate a concerning increase. A statistically significant rise in overall SMM rates was observed between 1998–1999 and 2010–2011. In the most recent period (2010–2011), for every 10,000 delivery hospitalizations, 163 involved at least one SMM indicator, representing a 26.1% increase from the previous two-year period (2008-2009). Blood transfusion consistently remained the most common SMM indicator throughout this period.
FIG. 4.
Trends in severe maternal morbidity during delivery hospitalizations in the United States from 1998 to 2011, showing a statistically significant increase in SMM rates.
While direct comparisons of overall SMM rates with other developed countries are limited, comparisons for specific indicators like eclampsia and hysterectomy are possible. In 2010, U.S. rates for eclampsia and hysterectomy were within the range observed in European countries reporting these data, suggesting relative parity for these specific morbidities.10,19
The increasing prevalence of SMM, currently affecting over 60,000 women annually in the U.S., is likely driven by factors such as rising maternal age,23 pre-pregnancy obesity,24–25 pre-existing chronic medical conditions,3–6 and cesarean delivery rates.23,26 The consequences of this rise include increased healthcare utilization, higher medical costs, prolonged hospital stays, and the need for long-term rehabilitation.18
While the use of administrative data for SMM surveillance has limitations, primarily relying on billing codes, it offers a valuable tool for understanding broad trends in severe maternal health outcomes. Importantly, SMM surveillance provides a more comprehensive view of disease patterns among pregnant and postpartum women than mortality data alone. This broader perspective is crucial for identifying intervention points for quality improvement in maternal care and for allocating resources effectively to prevent and manage these conditions. The CDC emphasizes that in-depth review and analysis of risk factors for maternal morbidity should become standard practice in all U.S. hospitals caring for pregnant women, complementing population-level surveillance efforts.
Maternal Substance Abuse: Current Challenges and Interventions
Maternal substance abuse continues to be a significant public health concern in the United States. Smoking during pregnancy elevates the risk of serious complications such as placenta previa, placental abruption, and premature rupture of membranes.28 PRAMS data from 29 states indicate that in the three months prior to pregnancy, approximately 23% of women smoked, and this decreased to 13% during the last three months of pregnancy.29 Disparities in smoking prevalence persist across maternal age, race/ethnicity, socioeconomic status, and state of residence.29 The DRH actively works to evaluate and promote effective clinical and policy interventions to reduce maternal smoking. Examples include the “Smoking Cessation for Pregnancy and Beyond: A Virtual Clinic” online training program30 and contributions to WHO recommendations for preventing and managing tobacco use during pregnancy.31 Future research directions include assessing the cost-effectiveness of financial incentives for prenatal smoking cessation and evaluating the efficacy of telephone-based quitlines and interventions to prevent smoking during pregnancy and postpartum.
Illicit drug use during pregnancy also presents a significant challenge. While prevalence is highest in the first trimester and tends to decrease as pregnancy progresses,32,33 some women continue to use illicit drugs throughout their pregnancies.32 National surveys indicate that illicit drug use among pregnant women aged 15–44 has remained relatively stable since the early 2000s, with a 2011 estimate of 5.0%.34 However, the types of drugs used have shifted, with a notable increase in maternal opiate use between 2000 and 2009.35–37,38 This rise mirrors broader trends of opioid misuse and abuse among women of all ages.39
Neonatal Abstinence Syndrome (NAS), affecting infants exposed to illicit substances or prescription medications, particularly opiates, is a serious consequence of maternal drug use.35 NAS incidence increased significantly between 2000 and 2009, from 1.2 to 3.4 per 1,000 births.38 Drug exposure in utero is linked to adverse pregnancy and neonatal outcomes, including low birth weight, small for gestational age, and prematurity.35,40 Long-term developmental challenges, including psychomotor and cognitive deficits and behavioral disorders, are also more common in drug-exposed children.41,42
The CDC’s DRH is actively engaged in addressing perinatal illicit drug use and NAS. Expert meetings, collaborations with State Health Departments, and exploration of Prescription Drug Monitoring Program data are underway to improve screening, intervention, and treatment strategies for pregnant and postpartum women struggling with drug abuse.
Mental Health During Pregnancy: Addressing Present Needs
Mental health disorders, particularly depression and anxiety, are prevalent and significantly impact the well-being of women and their families. NSDUH data reveals that approximately 1 in 10 women experience a major depressive episode annually.34 Women with depression face increased risks of substance abuse, chronic diseases, and poorer overall health.43,44 Alarmingly, only about half of pregnant and nonpregnant women with depression receive treatment.45 Poor mental health during pregnancy and postpartum can negatively affect pregnancy outcomes, maternal-infant bonding, maternal functioning, and infant health and development.46,47
Recognizing the significant burden of mental health disorders, the CDC’s DRH works to improve the mental health of women of reproductive age through research and technical assistance. Data from various sources, including NSDUH, PRAMS, and BRFSS, are utilized to provide national and state-level information on the prevalence and risk factors for mental health conditions, associated health issues, and treatment strategies. The DRH also supports states and organizations in developing and implementing public health strategies to address mental health among women of reproductive age.
Future priorities include identifying and alleviating barriers to mental health diagnosis and treatment, integrating mental health services into routine prenatal and well-woman care, and developing interventions that address both risky health behaviors and mental health disorders in this population.
Conclusion
Preventing maternal morbidity and mortality and eliminating health disparities in maternal health are critical national public health and research priorities. While maternal mortality has long served as a key indicator of maternal health, maternal morbidity is far more frequent, and both provide crucial insights for improving healthcare. The CDC’s 25 years of pregnancy-related mortality surveillance, coupled with collaborative efforts with national partners such as the American College of Obstetricians and Gynecologists and the National Institutes of Health, underscore a concerted effort to enhance maternal health outcomes in the United States. Where are we headed? The ongoing surveillance, research, and collaborative initiatives are crucial steps towards a future where every pregnancy is safer and every mother thrives.
Disclosure Statement
The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention. No competing financial interests exist.
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