Troubling news: Maternal mortality is on the rise
Why has a decades-long trend reversed? And what can we do to keep our patients safe?
This past summer, the National Center for Health Statistics reported that the maternal mortality rate in the United States is increasing.1 Analysts came to that conclusion after examining the latest (2004) final data on maternal deaths.
What’s causing this rise? And what should our response be as clinicians and as a specialty?
Tracking an 80-year downward trend
Here are notable snapshots from the recent US history of maternal mortality:
1930 Maternal mortality was 670 deaths for every 100,000 live births
1931 to 1960 Improvements in obstetric practices, anesthesiology, and blood banking resulted in a striking reduction in maternal mortality
1982 to 1996 The low rate held steady—in the range of 7 or 8 maternal deaths for every 100,000 live births2
2003 and 2004 The rate then increased—to 12 and 13.1 maternal deaths, respectively, for every 100,000 live births.1
The cause of the turnaround isn’t clear-cut
It is likely that enhanced identification of maternal deaths and an actual increase in deaths have contributed to the reported increase.
Tracking of deaths has changed
Methods used to define and identify deaths of pregnant women continue to evolve.
Historically, “maternal death” was narrowly defined as “the death of a woman while pregnant or within 42 days after termination of pregnancy, from any cause related to or aggravated by the pregnancy or its management.”1 In general, recognized obstetric causes are limited to diagnosis codes in the obstetrics chapter of the International Classification of Diseases.
More recently, public health specialists have developed expanded definitions of death among pregnant women to include “pregnancy-related deaths” and “pregnancy-associated deaths.”3
Pregnancy-related death is the “death of a woman while pregnant or within 1 year of termination of pregnancy, regardless of duration and site of pregnancy, from any cause related to or aggravated by her pregnancy or its management.”3 Judgments about “causality” and “aggravation” are typically made by an expert panel of clinicians and public health officials after detailed review of cases.
A death is “pregnancy-related” if it has a causal relationship to pregnancy, defined as:
- a complication of pregnancy itself
- a chain of events initiated by pregnancy
- aggravation of an unrelated event or condition by the physiologic effects of pregnancy.
Within the category of pregnancy-related death, a “direct” death is one that results from obstetric complications of pregnancy; an “indirect” death results from preexisting disease.
Pregnancy-associated death is more broadly defined as the death of a woman, from any cause, while she is pregnant or within 1 year after she terminates a pregnancy.
In short, maternal death is most likely underreported.3,4 As state vital statistics registries adopt broader concepts of obstetric causes of maternal death and improve case-finding methods, it is probable that reported maternal death rates will continue to increase.
A true rise in maternal deaths?
Many specialists are concerned that changes in patient characteristics, such as a marked increase in obesity, and evolving obstetric practices, such as a higher rate of cesarean delivery, may be contributing to a significant increase in maternal mortality. Today, the most common reported direct causes of maternal death5-10 are:
- maternal hemorrhage
- preeclampsia and other hypertensive disorders of pregnancy
- cerebrovascular accident
- amniotic fluid embolism and
- deep venous thrombosis with pulmonary embolism.
Better care will yield better outcomes, and fewer deaths
Obstetricians need to take action to help reduce the number of maternal deaths caused by the diseases and conditions listed in the preceding paragraph; in addition, a number of health-system approaches have the potential to contribute to such a reduction (see the TABLE).
A drive to reduce the rate of maternal death touches on every aspect of obstetrics and gynecology—from providing adequate prenatal services, including community-based general medicine and psychiatric services, to performing complex hysterectomy rapidly in women experiencing massive obstetric hemorrhage caused by placenta previa and placenta accreta. Community-based general medicine and psychiatric services will help women who have a chronic medical problem, such as hypertension, diabetes, or depression, to enter pregnancy in the best possible health. Sharper clinical skills and hospitals’ response to such obstetric catastrophes as postpartum hemorrhage will also mean better outcomes. Last, approaches to reducing maternal death must be multimodal and must include sound protocols for system response.
Some of the best approaches to reducing maternal mortality—for example, early delivery of women with preeclampsia—may increase neonatal morbidity and mortality. Grappling with the trade-off between the health and safety of a mother and that of her newborn is a complex conundrum at the core of the art of obstetric practice.
What can be done to reduce maternal mortality?
Actions for the health system to consider
Lifesaving attention to black patients is needed
It’s a recurring observation that Hispanic and white (non-Hispanic) women have a consistently lower maternal death rate than black women do (see the accompanying figure). This observation likely does not reflect any difference in case finding or in the definition of maternal mortality across states. There is a higher rate of obstetric problems, including preeclampsia, among black women that may account for a percentage of the difference, but the contribution of those problems to a racial discrepancy would be small.1
The fact that black women have a markedly increased rate of maternal death for uncertain reasons establishes a clear need for focused research—the goal being to develop targeted interventions to reduce maternal death in this racial group.
Among black women, a disproportionately high rate of maternal death
Source: From Table 34 on page 103 of Miniño AM, Heron MP, Murphy SL, Kochanek KD. Deaths: final data for 2004. Natl Vital Stat Rep. 2007;55(19):1–120.
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1. Miniño AM, Heron MP, Murphy SL, Kochanek KD. Deaths: final data for 2004. Natl Vital Stat Rep. 2007;55(19):1-120[cited on pages 12-13].
2. Centers for Disease Control and Prevention (CDC) Maternal mortality—United States, 1982-1996. MMWR Morb Mortal Wkly Rep. 1998;47:705-707.
3. Deneux-Tharaux C, Berg C, Bouvier-Colle MH, et al. Under-reporting of pregnancy-related mortality in the United States and Europe. Obstet Gynecol. 2005;106:684-692.
4. Schuitemaker N, Van Roosmalen J, Dekker G, Van Dongen P, Van Geijn H, Gravenhorst JB. Underreporting of maternal mortality in the Netherlands. Obstet Gynecol. 1997;90:780-792.
5. Panchal S, Arria AM, Labhsetwar SA. Maternal mortality during hospital admission for delivery: a retrospective analysis using a state-maintained database. Anesth Analg. 2001;93:134-141.
6. Jacob S, Bloebaum L, Shah G, Varner MW. Maternal mortality in Utah. Obstet Gynecol. 1998;91:187-191.
7. Panting-Kemp A, Geller SE, Nguyen T, Simonson L, Nuwayhid B, Castro L. Maternal deaths in an urban perinatal network, 1992-1998. Am J Obstet Gynecol. 2000;183:1207-1212.
8. Berg CJ, Chang J, Callaghan WM, Whitehead SJ. Pregnancy-related mortality in the United States, 1991-1997. Obstet Gynecol. 2003;101:289-296.
9. Berg CJ, Harper MA, Atkinson SM, et al. Preventability of pregnancy-related deaths. Obstet Gynecol. 2005;106:1228-1234.
10. Kilpatrick SJ, Crabtree KE, Kemp A, Geller S. Preventability of maternal deaths: comparison between Zambian and American referral hospitals. Obstet Gynecol. 2002;100:321-326.