Fetal Death Certificate Data Research Articles

Impact of the ARRIVE Trial on Stillbirth Rates in Nulliparous Individuals.

We aim to examine the population-level rates of induction, stillbirth, perinatal mortality, and neonatal death before and after the ARRIVE (A Randomized Trial of Induction Versus Expectant Management) trial. This study was a cross-sectional analysis of publicly available U.S. Live Birth data linked with Infant Death and Fetal Death certificate data from National Vital Statistics Online. We limited analyses to nulliparous individuals with singleton pregnancy and cephalic presentation who delivered at 39 weeks or greater. The pre- and post-ARRIVE periods spanned from August 2016 to July 2018, and from January 2019 to December 2020, respectively. Our primary outcome was a stillbirth. Secondary outcomes included induction of labor, perinatal mortality, and neonatal death. Outcomes were compared between the pre- and post-ARRIVE periods. Modified Poisson regression was used to calculate adjusted relative risks (aRRs). Of 2,817,071 births, there were 1,454,346 births in the pre-ARRIVE period and 1,362,725 in the post-ARRIVE period; there were 1,196 and 1,062 stillbirths in the pre- and post-ARRIVE periods, respectively. Compared to the pre-ARRIVE period, the post-ARRIVE period was not associated with a significant decrease in the risk of stillbirth at 39 weeks or greater (aRR 0.92 [95% confidence interval {95% CI} 0.85-1.00]) and stillbirth at 40 weeks or greater (aRR 0.92 [95% CI 0.82-1.04]). Compared to the pre-ARRIVE trial period, the post-ARRIVE trial was associated with increased rates of induction of labor at 39 weeks (aRR 1.37 [95% CI 1.37-1.38]) and 40 weeks (aRR 1.24 [95% CI 1.24-1.25]. Similar to stillbirth, there was no significant decrease in the risk of perinatal mortality at 39 weeks or greater or 40 weeks or greater. There was also no statistically significant change in neonatal death rates at 39 weeks or greater or at 40 weeks or greater. The increase in induction of labor at 39 weeks was not large enough to impact the stillbirth rate at 39 weeks or greater. · Post-ARRIVE trial, rate of induction of labor increased at 39 and 40 weeks.. · Post-ARRIVE trial, stillbirth and perinatal mortality rates remained unchanged.. · Induction rate rise post-ARRIVE trial did not impact neonatal death rates..

Racial and ethnic disparities in severe maternal morbidity from pregnancy through 1-year postpartum

BACKGROUNDPrevious studies examining racial and ethnic disparities in severe maternal morbidity (SMM) have mainly focused on intrapartum hospitalization. There is limited information regarding the racial and ethnic distribution of SMM occurring in the antepartum and postpartum periods, including SMM occurring beyond the traditional 6 weeks postpartum period. OBJECTIVETo examine the racial and ethnic distribution of SMM during antepartum, intrapartum, and postpartum hospitalizations through 1-year postpartum, overall and stratified by maternal sociodemographic factors, and to estimate the percent increase in SMM by race and ethnicity and maternal sociodemographic factors within each racial and ethnic group after accounting for both antepartum and postpartum SMM through 1-year postpartum rather than just SMM occurring during the intrapartum hospitalization. STUDY DESIGNWe conducted a retrospective cohort study using birth and fetal death certificate data linked to hospital discharge records from Michigan, Oregon, and South Carolina from 2008–2020. We examined the distribution of non-transfusion SMM and total SMM per 10,000 cases during antepartum, intrapartum, and postpartum hospitalizations through 365 days postpartum by race and ethnicity and by maternal education and insurance type within each racial and ethnic group. We subsequently examined “SMM cases added” by race and ethnicity and by maternal education and insurance type within each racial and ethnic group. The “SMM cases added” represent cases among unique individuals that are identified by considering the antepartum and postpartum periods but that would be missed if only the intrapartum hospitalization cases were included. RESULTSAmong 2,584,206 birthing individuals, a total of 37,112 (1.4%) individuals experienced non-transfusion SMM and 64,661 (2.5%) experienced any SMM during antepartum, intrapartum, and/or postpartum hospitalization. Black individuals had the highest rate of antepartum, intrapartum, and postpartum non-transfusion and total SMM followed by American Indian individuals. Asian individuals had the lowest rate of non-transfusion and total SMM during antepartum and postpartum hospitalizations while White individuals had the lowest rate of non-transfusion and total SMM during the intrapartum hospitalization. Black individuals were 1.9 times more likely to experience non-transfusion SMM during the intrapartum hospitalization than White individuals, which increased to 2.8 times during the antepartum period and to 2.5 times during the postpartum period. Asian and Hispanic individuals were less likely to experience SMM in the postpartum period than White individuals. Including antepartum and postpartum hospitalizations resulted in disproportionately more cases among Black and American Indian individuals than among White, Hispanic, and Asian individuals. The additional cases were also more likely to occur among individuals with lower educational levels and individuals on government insurance. CONCLUSIONRacial disparities in SMM are underreported in estimates that focus on the intrapartum hospitalization. Additionally, individuals with low socio-economic status bear the greatest burden of SMM occurring during the antepartum and postpartum periods. Approaches that focus on mitigating SMM during the intrapartum period only do not address the full spectrum of health disparities.El resumen está disponible en Español al final del artículo.

Severe maternal morbidity from pregnancy through 1 year postpartum

Few recent studies have examined the rate of severe maternal morbidity occurring during the antenatal and/or postpartum period to 42 days after delivery. However, little is known about the rate of severe maternal morbidity occurring beyond 42 days after delivery. This study aimed to examine the distribution of severe maternal morbidity and its indicators during antenatal, delivery, and postpartum hospitalizations to 365 days after delivery and to estimate the increase in severe maternal morbidity rate and its indicators after accounting for antenatal and postpartum severe maternal morbidity to 365 days after delivery. This was a retrospective cohort study using birth and fetal death certificate data linked to hospital discharge records from Michigan, Oregon, and South Carolina from 2008 to 2020. This study examined the distribution of severe maternal morbidity, nontransfusion severe maternal morbidity, and severe maternal morbidity indicators during antenatal, delivery, and postpartum hospitalizations to 365 days after delivery. Subsequently, this study examined "severe maternal morbidity cases added," which represent cases among unique individuals that are included by considering the antenatal and postpartum periods but that would be missed if only the delivery hospitalization cases were included. A total of 64,661 (2.5%) individuals experienced severe maternal morbidity, whereas 37,112 (1.4%) individuals experienced nontransfusion severe maternal morbidity during antenatal, delivery, and/or postpartum hospitalization. A total of 31% of severe maternal morbidity cases were added after accounting for severe maternal morbidity occurring during the antenatal or postpartum hospitalization to 365 days after delivery, whereas 49% of nontransfusion severe maternal morbidity cases were added after accounting for nontransfusion severe maternal morbidity occurring during the antenatal or postpartum periods. Severe maternal morbidity occurring between 43 and 365 days after delivery contributed to 12% of all severe maternal morbidity cases, whereas nontransfusion severe maternal morbidity occurring between 43 and 365 days after delivery contributed to 19% of all nontransfusion severe maternal morbidity cases. Our study showed that a total of 31% of severe maternal morbidity and 49% of nontransfusion severe maternal morbidity cases were added after accounting for severe maternal morbidity occurring during the antenatal or postpartum hospitalization to 365 days after delivery. Our findings highlight the importance of expanding the severe maternal morbidity definition beyond the delivery hospitalization to better capture the full period of increased risk, identify contributing factors, and design strategies to mitigate this risk. Only then can we improve outcomes for mothers and subsequently the quality of life of their infants.

Association between stillbirth and severe maternal morbidity

Severe maternal morbidity has been increasing in the past few decades. Few studies have examined the risk of severe maternal morbidity among individuals with stillbirths vs individuals with live-birth deliveries. This study aimed to examine the prevalence and risk of severe maternal morbidity among individuals with stillbirths vs individuals with live-birth deliveries during delivery hospitalization as a primary outcome and during the postpartum period as a secondary outcome. This was a retrospective cohort study using birth and fetal death certificate data linked to hospital discharge records from California (2008-2018), Michigan (2008-2020), Missouri (2008-2014), Pennsylvania (2008-2014), and South Carolina (2008-2020). Relative risk regression analysis was used to examine the crude and adjusted relative risks of severe maternal morbidity along with 95% confidence intervals among individuals with stillbirths vs individuals with live-birth deliveries, adjusting for birth year, state of residence, maternal sociodemographic characteristics, and the obstetric comorbidity index. Of the 8,694,912 deliveries, 35,012 (0.40%) were stillbirths. Compared with individuals with live-birth deliveries, those with stillbirths were more likely to be non-Hispanic Black (10.8% vs 20.5%); have Medicaid (46.5% vs 52.0%); have pregnancy complications, including preexisting diabetes mellitus (1.1% vs 4.3%), preexisting hypertension (2.3% vs 6.2%), and preeclampsia (4.4% vs 8.4%); have multiple pregnancies (1.6% vs 6.2%); and reside in South Carolina (7.4% vs 11.6%). During delivery hospitalization, the prevalence rates of severe maternal morbidity were 791 cases per 10,000 deliveries for stillbirths and 154 cases per 10,000 deliveries for live-birth deliveries, whereas the prevalence rates for nontransfusion severe maternal morbidity were 502 cases per 10,000 deliveries for stillbirths and 68 cases per 10,000 deliveries for live-birth deliveries. The crude relative risk for severe maternal morbidity was 5.1 (95% confidence interval, 4.9-5.3), whereas the adjusted relative risk was 1.6 (95% confidence interval, 1.5-1.8). For nontransfusion severe maternal morbidity among stillbirths vs live-birth deliveries, the crude relative risk was 7.4 (95% confidence interval, 7.0-7.7), whereas the adjusted relative risk was 2.0 (95% confidence interval, 1.8-2.3). This risk was not only elevated among individuals with stillbirth during the delivery hospitalization but also through 1 year after delivery (severe maternal morbidity adjusted relative risk, 1.3; 95% confidence interval, 1.1-1.4; nontransfusion severe maternal morbidity adjusted relative risk, 1.2; 95% confidence interval, 1.1-1.3). Stillbirth was found to be an important contributor to severe maternal morbidity.

35 Additive risk of chronic hypertension in women with pregestational diabetes

Pregestational diabetes (PDM) often co-exists with chronic hypertension (cHTN), and both are associated with substantial risk for several adverse perinatal outcomes including fetal death. We sought to quantify the additive risk of a concurrent diagnosis of chronic hypertension and pregestational diabetes on pregnancy outcomes. This was a population based retrospective cohort study of all singleton births in the United States occurring >20 weeks’ gestation using national live birth and fetal death certificate data from 2018. Patients were grouped by presence of underlying cHTN, PDM, both or none. Baseline demographics and pregnancy outcomes were compared in a univariate analysis. Poisson regression with robust error variance was used to generate adjusted relative risks (aRR) and 95% confidence intervals (CI) for the studied outcome controlling for confounders. There were 3,590,179 women included in the analysis and 0.8% had PDM, 1.9% had cHTN and 0.2% had both. There were increased risks of all studied outcomes in women with PDM or cHTN compared to women without PDM or cHTN, but these risks were greatest when both co-morbidities were present (Table 1). Women with both conditions had significantly increased risks of both early (aRR 5.08, CI 3.95-6.53) and late (aRR 7.10, CI 5.74-8.77) fetal death (Figure 1). Large (LGA) and small for gestational age (SGA) birthweight was more common in women with only PDM and cHTN, respectively. However, women with both had reduced rates of LGA (25.9% vs 30.2%; p<.001) and increased rates of SGA (8.9% vs 6.3%; p<.001) when compared to PDM alone. Women with both PDM and cHTN have substantially increased risks for adverse perinatal outcomes that appear to be additive to having either condition alone. The fetal growth pattern seen in these patients may represent the combined effect of hyperglycemia and placental insufficiency, which could contribute to the increased rates of fetal death in this population.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

A case-crossover study of short-term air pollution exposure and the risk of stillbirth in California, 1999–2009

BackgroundAssociations between ambient air pollution and stillbirth have recently been explored, but most studies have focused on long-term (trimester or gestational averages) rather than short-term (within one week) air pollution exposures. ObjectiveTo evaluate whether short-term exposures to criteria air pollutants are associated with increased risk of stillbirth. MethodsUsing air pollution and fetal death certificate data from 1999 to 2009, we assessed associations between acute prenatal air pollution exposure and stillbirth in California. In a time-stratified case-crossover study, we analyzed single day and/or cumulative average days (up to a 6 day lag) of exposure to fine (PM2.5) and coarse particles (PM10-2.5), ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO) for mothers estimated to reside within 10 km of a pollution monitor based on reported zip code. We also examined potential confounding by apparent temperature or co-pollutants, and effect modification by maternal demographic factors, fetal sex, gestational age, and cause of stillbirth. ResultsStillbirth cases in the primary analyses ranged between 1,203 and 13,018, depending on the pollutant. For an IQR increase in SO2 (lag 4), O3 (lag 4), and PM10-2.5 (lag 2), we found a 2.8% (95% confidence interval (CI) 0.2%, 5.5%), 5.8% (95% CI 1.6%, 10.1%), and 6.1% (95% CI 0.1%, 12.4%) increase in the odds of stillbirth, respectively. Additional adjustment by apparent temperature had little effect on the SO2 association but slightly attenuated O3 (adjusted % change: 4.2% (95% CI -0.2%, 8.9%) and PM10-2.5 (5.7% (95% CI -1.1%, 13.0%)) associations, while other co-pollutants had minimal impact. Associations were observed specifically for stillbirths from obstetric complications and in women with higher educational attainment. ConclusionsThis study provides evidence for associations between prenatal short-term air pollution exposure, specifically SO2, O3, and PM10-2.5, and stillbirth in California and warrants replication of findings in other settings.

Influence of Work Characteristics on the Association Between Perceived Police Stress Severity and Sleep Quality

Describe the relative frequency and joint effect of missing and misreported fetal death certificate (FDC) data and identify variations by key characteristics.Stillbirths were prospectively identified during 2006–2008 for a multisite population-based case-control study. For this study, eligible mothers of stillbirths were not incarcerated residents of DeKalb County, Georgia, or Salt Lake County, Utah, aged ≥13 years, with an identifiable FDC. We identified the frequency of missing and misreported (any departure from the study value) FDC data by county, race/ethnicity, gestational age, and whether the stillbirth was antepartum or intrapartum.Data quality varied by item and was highest in Salt Lake County. Reporting was generally not associated with maternal or delivery characteristics. Reasons for poor data quality varied by item in DeKalb County: some items were frequently missing and misreported; however, others were of poor quality due to either missing or misreported data.FDC data suffer from missing and inaccurate data, with variations by item and county. Salt Lake County data illustrate that high quality reporting is attainable. The overall quality of reporting must be improved to support consequential epidemiologic analyses for stillbirth, and improvement efforts should be tailored to the needs of each jurisdiction.

Anne Jurek, PhD, MS winner of the American College of Epidemiology Annals of Epidemiology Award, 2017

Describe the relative frequency and joint effect of missing and misreported fetal death certificate (FDC) data and identify variations by key characteristics.Stillbirths were prospectively identified during 2006–2008 for a multisite population-based case-control study. For this study, eligible mothers of stillbirths were not incarcerated residents of DeKalb County, Georgia, or Salt Lake County, Utah, aged ≥13 years, with an identifiable FDC. We identified the frequency of missing and misreported (any departure from the study value) FDC data by county, race/ethnicity, gestational age, and whether the stillbirth was antepartum or intrapartum.Data quality varied by item and was highest in Salt Lake County. Reporting was generally not associated with maternal or delivery characteristics. Reasons for poor data quality varied by item in DeKalb County: some items were frequently missing and misreported; however, others were of poor quality due to either missing or misreported data.FDC data suffer from missing and inaccurate data, with variations by item and county. Salt Lake County data illustrate that high quality reporting is attainable. The overall quality of reporting must be improved to support consequential epidemiologic analyses for stillbirth, and improvement efforts should be tailored to the needs of each jurisdiction.

Fetal death certificate data quality: a tale of two U.S. counties

PurposeDescribe the relative frequency and joint effect of missing and misreported fetal death certificate (FDC) data and identify variations by key characteristics. MethodsStillbirths were prospectively identified during 2006–2008 for a multisite population-based case-control study. For this study, eligible mothers of stillbirths were not incarcerated residents of DeKalb County, Georgia, or Salt Lake County, Utah, aged ≥13 years, with an identifiable FDC. We identified the frequency of missing and misreported (any departure from the study value) FDC data by county, race/ethnicity, gestational age, and whether the stillbirth was antepartum or intrapartum. ResultsData quality varied by item and was highest in Salt Lake County. Reporting was generally not associated with maternal or delivery characteristics. Reasons for poor data quality varied by item in DeKalb County: some items were frequently missing and misreported; however, others were of poor quality due to either missing or misreported data. ConclusionsFDC data suffer from missing and inaccurate data, with variations by item and county. Salt Lake County data illustrate that high quality reporting is attainable. The overall quality of reporting must be improved to support consequential epidemiologic analyses for stillbirth, and improvement efforts should be tailored to the needs of each jurisdiction.

Hospital trauma level's association with outcomes for injured pregnant women and their neonates in Washington state, 1995-2012.

Background:Trauma occurs in 8% of all pregnancies. To date, no studies have evaluated the effect of the hospital's trauma designation level as it relates to birth outcomes for injured pregnant women.Methods:This population-based, retrospective cohort study evaluated the association between trauma designation levels and injured pregnancy birth outcomes. We linked Washington State Birth and Fetal Death Certificate data and the Washington State Comprehensive Hospital Recording System. Injury was identified using the International Classification of Diseases, Ninth Revision injury diagnosis and external causation codes. The association was analyzed using logistic regression to estimate odds ratios and 95% confidence intervals (CIs).Results:We identified 2492 injured pregnant women. Most birth outcomes studied, including placental abruption, induction of labor, premature rupture of membranes, cesarean delivery, maternal death, gestational age <37 weeks, fetal distress, fetal death, neonatal respiratory distress, and neonatal death, showed no association with trauma hospital level designation. Patients at trauma Level 1–2 hospitals had a 43% increased odds of preterm labor (95% CI: 1.15–1.79) and a 66% increased odds of meconium at delivery (95% CI: 1.05–2.61) compared to those treated at Level 3–4 hospitals. Patients with an injury severity score >9, treated at trauma Level 1–2 hospitals, had an aOR of low birth weight, <2500 g, of 2.52 (95% CI: 1.12–5.64).Conclusions:The majority of birth outcomes for injured patients had no association with hospitalization at a Level 1–2 compared to a Level 3–4 trauma center.

Stillbirth surveillance consortium

Stillbirths have an estimated prevalence of 6 per 1,000 live births and fetal deaths combined in the United States (U.S.), yet major risk factors for these adverse birth outcomes remain elusive [1,2]. Historically in the U.S., surveillance information about stillbirth has come from fetal death certificates maintained by the National Vital Statistics System. Data collection within the National Vital Statistics System is guided by the Model State Vital Statistics Act and Regulations (Model Law), which defines fetal loss as showing no signs of breath or cardiac activity after expulsion [3]. The Model Law also recommends reporting a fetal loss as a stillbirth if the fetus weighs 350 grams or greater, or if no birth weight is available, the fetus is at least 20 weeks in gestational age. Each state in the U.S. develops its own definition, reporting criteria, and fetal death certificate, which can produce variability in reporting across states [4]. Additionally, previous studies suggest that fetal death certificate data are limited in utility as a source for national stillbirth surveillance due to under- or over-reporting and the completeness and quality of recorded data [5]. An alternative approach to surveillance of stillbirths is the use of established birth defect surveillance systems to incorporate active case finding for stillbirths. This approach permits population-based identification of affected pregnancies and characterization of the epidemiology of these pregnancies. In 2005, the Centers for Disease Control and Prevention established projects for stillbirth surveillance using the established infrastructures of the Metropolitan Atlanta Congenital Defects Program and the Iowa Registry for Congenital and Inherited Disorders, two premier birth defect surveillance systems in the U.S. The goals of our Iowa project, the Iowa Stillbirth Surveillance Project (ISSP), were to: evaluate the feasibility of expanding the Iowa Registry for Congenital and Inherited Disorders to incorporate data from existing records on stillbirths; monitor and report, as feasible, on the occurrence of stillbirths in the state of Iowa; serve as a registry for etiologic studies of stillbirths; and serve as a resource for education and evaluation of prevention programs that aim to reduce the occurrence of stillbirths . Active case finding and record abstraction approaches, originally developed for birth defect surveillance in Iowa, were used by the ISSP for state-wide ascertainment of stillbirths. We ascertained 1,301 reportable stillbirths (≥20 weeks gestation or ≥350 grams delivery weight) delivered from January 1, 2005 through December 31, 2011. Surveillance data collected are being used to estimate population-based prevalence estimates for stillbirths in Iowa and to examine fetal and parental characteristics associated with stillbirths. Also, these data are being used to conduct individual-level geospatial surveillance of stillbirths. Knowledge of the spatial patterns of stillbirths may provide important insights into possible links to environmental exposures and the opportunity to plan detailed etiological investigations. We continue to monitor stillbirths among the approximately 40,000 deliveries in Iowa annually. In 2012, we also expanded active case finding and record abstraction for stillbirths to include birth defect surveillance systems in Colorado, Hawaii, and New York State. This Stillbirth Surveillance Consortium (SSC) uses similar surveillance methods and tools to provide a systematic approach to population-based surveillance of stillbirths and covers more than 120,000 deliveries annually with a diverse racial/ethnic composition. To date, the SSC has ascertained 784 reportable stillbirths delivered from January 1, 2010 through December 31, 2011. Surveillance data collected by the SSC will expand ongoing analyses by the ISSP for prevalence estimation, examination of fetal and parental characteristics, and individual-level geospatial surveillance. The methods developed by the SSC can serve as a model for other states to expand birth defect surveillance programs to include active case finding and record abstraction for stillbirths.

Correlation Between Stillbirth Vital Statistics and Medical Records

Most data regarding conditions associated with or contributing to stillbirth are derived from fetal death certificates. Our purposes were to compare stillbirth data recorded in vital statistics with those in the medical record and to investigate whether diagnostic evaluations differed in tertiary care and community hospitals. In this cross-sectional study, fetal death certificate data identified individuals with stillbirths delivering in eight Salt Lake City hospitals from 1998 to 2002. Medical records were reviewed to assess demographics, diagnostic evaluation, and potential causes of stillbirth. Data were compared between death certificates and the medical record by calculation of the κ coefficient for categorical variables or Kendall's τ-b coefficients based on the number of concordant and discordant pairs of observations for continuous variables. Diagnostic tests completed were compared between community and tertiary care hospitals with χ or Fisher exact test. Five-hundred fifty-six individuals were identified, and 461 (83%) charts were available for review. Correlation between death certificates and the medical record was nearly perfect for demographic variables (correlation 0.8-0.9) but slight to moderate (correlation 0.2-0.5) for contributing or etiologic factors. Important diagnostic tests performed significantly more often in tertiary care than community hospitals included autopsy (35% compared with 13%, P<.01), karyotype (17% compared with 4%, P<.01), Kleihauer-Betke (22% compared with 13%, P=.01), toxicology screen (13% compared with 2%, P<.01), and complete blood count (95% compared with 90%, P=.03). There are important discrepancies between fetal death certificates and medical records. Complete work-up, review of the medical record, and efforts to increase accurate reporting may improve the accuracy of stillbirth vital statistics. Diagnostic evaluation was more extensive in tertiary care hospitals.

The Effect of Air Bags on Pregnancy Outcomes in Washington State

To estimate whether air-bag deployment is associated with an increased risk of adverse pregnancy outcomes. We performed a retrospective cohort study to assess the effect of air-bag availability and air-bag deployment on the risk of adverse pregnancy outcomes among pregnant, front-seat occupants in motor vehicle crashes in Washington State. Pregnant women involved in motor vehicle crashes were identified by linking birth and fetal death certificate data with Washington State Patrol crash data, which reported air-bag availability and deployment. We calculated relative risks (RRs) of adverse maternal and perinatal outcomes and 95% confidence intervals (CIs) using Poisson regression, adjusted for maternal age, seatbelt use, and vehicle model year. We found no increased risk of adverse maternal or perinatal pregnancy outcomes among occupants of air-bag-equipped vehicles in all collisions (n=2,207) compared with those in vehicles without air bags (n=1,141). Among crashes in which air-bag deployment would be likely, we found a nonsignificant 70% increased risk of preterm labor (RR 1.7, 95% CI 0.9-3.2) and a nonsignificant threefold increased risk (RR 3.1, 95% CI 0.4-22.1) of fetal death among occupants in vehicles with air-bag deployment compared with occupants in vehicles without air bags, although fetal death results were limited by small numbers (2/198 [1.0%] in pregnant women whose air bags deployed; 2/622 [0.3%] in pregnant women whose air bags did not deploy). Our findings provide clinicians with evidence to advise women that air bags do not seem to elevate risk of most potential adverse outcomes during pregnancy. II.

Identifying Multiple Gestation Groups Using State-Level Birth and Fetal Death Certificate Data

Birth and fetal death certificates classify individuals as twins or higher order multiples, but do not identify multiple gestation groups. As a result, multiple gestations are consistently excluded from maternal and child health research studies despite the surge in multiple births since the early 1980s and the health risks associated with them. A standardized methodology for states to identify multiple gestation groups is proposed to allow researchers to account for multiple gestations in analyses, improve the accuracy of the incidence of multiple gestations and further knowledge of the impact of multiple gestations on birth outcomes. Using 3 years of Massachusetts birth and fetal death certificate data from 1998 to 2000 (247,959 births and 1358 fetal deaths), we assigned matching multiple gestation group numbers to records with identical combinations of mother's first name, last name, date of birth, and month of delivery. To validate our methodology, we calculated plurality and compared it to plurality reported on the existing birth and fetal death data. This method correctly identified 10,765 records out of 10,795 validated multiple gestation deliveries (99.8%). Our method identified 71 additional multiple gestation deliveries, which were not identified by the birth and fetal death files. This method resulted in only 4 false positives and 51 false negatives over 3 years. This algorithm provides much needed information on multiple gestation groupings, and as an additional benefit, improves the identification of multiple gestation deliveries. This method has proven easy to use, employs state-level data, and offers numerous new analytic opportunities.

Validity of Maternal and Perinatal Risk Factors Reported on Fetal Death Certificates

We sought to estimate the accuracy, relative to maternal medical records, of perinatal risk factors recorded on fetal death certificates. We conducted a validation study of fetal death certificates among women who experienced fetal deaths between 1996 and 2001. The number of previous births, established diabetes, chronic hypertension, maternal fever, performance of autopsy, anencephaly, and Down syndrome had very high accuracy, while placental cord conditions and other chromosomal abnormalities were reported inaccurately. Additional population-based studies are needed to identify strategies to improve fetal death certificate data.

Pregnancy‐associated injury hospitalizations: maternal and fetal outcomes

Background. Although injury is one of the leading causes of morbidity and mortality among reproductive-aged women, relatively little research has focused on pregnant women. The purpose of this study was to determine the incidence rate, causes, and outcomes of pregnancy-associated injury hospital- izations in Washington. Methods. A retrospective cohort design was used to evaluate women hospitalized for injury during pregnancy in Washington State from 1989 to 1997. Pregnant women hospitalized for injury were identified by linking Wash- ington state files containing birth and fetal death certificate data with hospital discharge data from all Washington state civilian hospitals, with injury defined as any ICD-9 injury diagnosis or external causation codes except poisonings and medical mis- adventures. These women were compared with a randomly chosen group of delivering women not experiencing an injury hospitalization during pregnancy. Pregnancy outcomes were evaluated using relative risks (RR) and 95% confidence intervals (95% CI). Results. The overall incidence of pregnancy- associated injury hospitalizations was 243.4/100 000 live births. Motor vehicle crashes (30.4%), falls (27.3%), and assaults (8.2%) were the most common causes of injuries. Pregnant women hos- pitalized for injury were at increased risk of placental abruption (RR 3.3, 95%CI 2.5-4.3), cesarean delivery (RR 1.2, 95%CI 1.1-1.3), and death (RR = 11.5, 95%CI 1.9-68.7) compared with non-injured pregnant women. Their infants were at increased risk of low birth weight (