October 21, 2016
A recent study that linked data from the North Carolina Maternal Mortality Review to the North Carolina Violent Death Reporting System (NC-VDRS) revealed that violent deaths occurring during pregnancy and up to one year postpartum are under-reported.
Injuries, including those resulting from violence, are a leading cause of death for women during pregnancy and the postpartum period. Before this study, it was unknown whether the traditional maternal mortality surveillance system in N.C. was accurately capturing all pregnancy-associated violent deaths.
Study co-author Anna Austin, MPH, is a doctoral student of maternal and child health, with an epidemiology minor, at the UNC Gillings School of Global Public Health. She worked with Catherine Vladutiu, PhD, an alumna of the Gillings School who now is a research assistant professor in UNC’s Department of Obstetrics & Gynecology and an adjunct assistant professor in the Gillings School’s Department of Epidemiology, and with researchers in the N.C. Division of Public Health and N.C. State Center for Health Statistics, to connect disparate sources of data on pregnancy-associated suicides and homicides.
The full article, titled “Improved Ascertainment of Pregnancy-Associated Suicides and Homicides in North Carolina,” was published online Oct. 13 in a special edition of the American Journal of Preventive Medicine.
In the study, the investigators linked data from the NC-VDRS to data from the traditional maternal mortality surveillance system for the years 2005 through 2011. Traditional system data include death certificates with any mention of pregnancy, death certificates matched to a live birth or fetal death record, and discharge records for women who died in the hospital with a pregnancy-related diagnosis.
This process identified 29 suicides and 55 homicides among pregnant and postpartum women, compared with previously reported numbers of 20 suicides and 34 homicides. Thus, pregnancy-related mortality ratios for suicide (3.3 versus 2.3 deaths per 100,000 live births) and homicide (6.2 versus 3.9 deaths per 100,000 live births) are higher than previously thought.
The researchers identified two possible explanations for the under-detection of pregnancy-associated violent deaths with the traditional surveillance system. First, pregnancy may not have been noted on death certificates, as a pregnancy checkbox was not added to death certificates in N.C. until 2014. In other states, however, the checkbox still has not been fully effective in identifying pregnancy-associated homicides and suicides.
Second, a live birth or fetal death certificate may not have existed for all pregnancy-associated homicides and suicides, as N.C. does not file certificates for fetal deaths occurring before 20 weeks gestation. The inclusion of medical examiner and autopsy reports in the NC-VDRS helped identify homicides and suicides occurring early in pregnancy.
In addition to revealing these gaps in collected data, the process of linking information from the maternal mortality surveillance system with the NC-VRDS offered more insight into the circumstances surrounding violent deaths. For example, the researchers found evidence that, among pregnancy-associated suicides, more than half of victims were reported to have one or more known mental health diagnoses, with 18 percent of the suicides being linked to postpartum depression. Similarly, the majority of pregnancy-associated homicides were revealed to be related to intimate partner violence (IPV).
This information highlights the importance of standard screening during prenatal and postnatal visits. The American Congress of Obstetricians and Gynecologists (ACOG) recommends screening for depression and anxiety symptoms at least once during the perinatal period. In this study, most prenatal suicides occurred during the first trimester of pregnancy, suggesting that screening during early pregnancy may be particularly important.
With regard to IPV, ACOG recommends that clinicians screen women at the first prenatal visit, at least once per trimester and at the first postpartum visit. In this study, more than half the homicides among postpartum women occurred more than six months post-delivery, indicating a need for continued vigilance beyond the initial postpartum visit. From a practical standpoint, this could occur at pediatric visits for the infant.
The co-authors note that the study has limitations: While linking traditional maternal mortality surveillance system records with the NC-VDRS captured 55.6 percent more pregnancy-associated violent deaths than traditional surveillance alone, such deaths still may be under-reported. Not all autopsies of women include an examination for pregnancy, and family and friends who provide information for law enforcement incident reports may be unaware of early or unintended pregnancies.
Ultimately, this research highlights the importance of utilizing multiple data sources to ensure accurate reporting of pregnancy-associated violent deaths. Further exploration into the causes of violent deaths of pregnant and postpartum women may aid in the development of effective strategies to prevent them.