The Association of Race and Ethnicity with Severe Maternal Morbidity among Individuals Diagnosed with Hypertensive Disorders of Pregnancy

OBJECTIVE

This study aimed to examine whether there are racial disparities in severe maternal morbidity (SMM) in patients with hypertensive disorders of pregnancy (HDP).

STUDY DESIGN

Secondary analysis of an observational study of 115,502 patients who had a live birth at ≥20 weeks in 25 hospitals in the United States from 2008 to 2011. Only patients with HDP were included in this analysis. Race and ethnicity were categorized as non-Hispanic White, non-Hispanic Black (NHB), and Hispanic and were abstracted from the medical charts. Patients of other races and ethnicities were excluded. Associations were estimated between race and ethnicity, and the primary outcome of SMM, defined as any of the following, was estimated by unadjusted logistic and multivariable backward logistic regressions: blood transfusion ≥4 units, unexpected surgical procedure, need for a ventilator ≥12 hours, intensive care unit (ICU) admission, or failure of ≥1 organ system. Multivariable models were run classifying HDP into three levels as follows: (1) gestational hypertension; (2) preeclampsia (mild, severe, or superimposed); and (3) eclampsia or HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome.

RESULTS

A total of 9,612 individuals with HDP met inclusion criteria. No maternal deaths occurred in this cohort. In univariable analysis, non-Hispanic White patients were more likely to present with gestational hypertension whereas NHB and Hispanic patients were more likely to present with preeclampsia. The frequency of the primary outcome, composite SMM, was higher in NHB patients compared with that in non-Hispanic White or Hispanic patients (11.8 vs. 4.5% in non-Hispanic White and 4.8% in Hispanic, p < 0.001). This difference was driven by a higher frequency of blood transfusions and ICU admissions among NHB individuals. Prior to adjusting the analysis for confounding factors, the odds ratio (OR) of primary composite outcomes in NHB individuals was 2.85 (95% confidence interval [CI]: 2.38, 3.42) compared with non-Hispanic White. After adjusting for sociodemographic and clinical factors, hospital site, and the severity of HDP, the OR of composite SMM did not differ between the groups (adjusted OR [aOR] = 1.26, 95% CI: 0.95, 1.67 for NHB, and aOR = 1.29, 95% CI: 0.94, 1.77 for Hispanic, compared with non-Hispanic White patients). Sensitivity analysis was done to exclude one single site that was an outliner with the highest ICU admissions and demonstrated no difference in ICU admission by maternal race and ethnicity.

CONCLUSION

NHB patients with HDP had higher rates of the composite SMM compared with non-Hispanic White patients, driven mainly by a higher frequency of blood transfusions and ICU admissions. However, once severity and other confounding factors were taken into account, the differences did not persist.

KEY POINTS

· Black patients with HDP had higher frequency of SMM compared with non-Hispanic White patients.. · The SMM disparities were driven by blood transfusions and ICU admissions.. · After adjustment for confounders, including HDP severity, the significant difference in SMM did not persist..

Birth hospital and racial and ethnic differences in severe maternal morbidity in the state of California

BACKGROUND

Birth hospital has recently emerged as a potential key contributor to disparities in severe maternal morbidity, but investigations on its contribution to racial and ethnic differences remain limited.

OBJECTIVE

We leveraged statewide data from California to examine whether birth hospital explained racial and ethnic differences in severe maternal morbidity.

STUDY DESIGN

This cohort study used data on all births at ≥20 weeks gestation in California (2007-2012). Severe maternal morbidity during birth hospitalization was measured using the Centers for Disease Control and Prevention index of having at least 1 of the 21 diagnoses and procedures (eg, eclampsia, blood transfusion, hysterectomy). Mixed-effects logistic regression models (ie, women nested within hospitals) were used to compare racial and ethnic differences in severe maternal morbidity before and after adjustment for maternal sociodemographic and pregnancy-related factors, comorbidities, and hospital characteristics. We also estimated the risk-standardized severe maternal morbidity rates for each hospital (N=245) and the percentage reduction in severe maternal morbidity if each group of racially and ethnically minoritized women gave birth at the same distribution of hospitals as non-Hispanic white women.

RESULTS

Of the 3,020,525 women who gave birth, 39,192 (1.3%) had severe maternal morbidity (2.1% Black; 1.3% US-born Hispanic; 1.3% foreign-born Hispanic; 1.3% Asian and Pacific Islander; 1.1% white; 1.6% American Indian and Alaska Native, and Mixed-race referred to as Other). Risk-standardized rates of severe maternal morbidity ranged from 0.3 to 4.0 per 100 births across hospitals. After adjusting for covariates, the odds of severe maternal morbidity were greater among nonwhite women than white women in a given hospital (Black: odds ratio, 1.25; 95% confidence interval, 1.19-1.31); US-born Hispanic: odds ratio, 1.25; 95% confidence interval, 1.20-1.29; foreign-born Hispanic: odds ratio, 1.17; 95% confidence interval, 1.11-1.24; Asian and Pacific Islander: odds ratio, 1.26; 95% confidence interval, 1.21-1.32; Other: odds ratio, 1.31; 95% confidence interval, 1.15-1.50). Among the studied hospital factors, only teaching status was associated with severe maternal morbidity in fully adjusted models. Although 33% of white women delivered in hospitals with the highest tertile of severe maternal morbidity rates compared with 53% of Black women, birth hospital only accounted for 7.8% of the differences in severe maternal morbidity comparing Black and white women and accounted for 16.1% to 24.2% of the differences for all other racial and ethnic groups.

CONCLUSION

In California, excess odds of severe maternal morbidity among racially and ethnically minoritized women were not fully explained by birth hospital. Structural causes of racial and ethnic disparities in severe maternal morbidity may vary by region, which warrants further examination to inform effective policies.

Descriptive and clinical epidemiology of preeclampsia and eclampsia in Florida

OBJECTIVE

To calculate preeclampsia/eclampsia rates for Florida and identify risk factors for prolonged length of stay (PLOS) among women hospitalized throughout Florida for preeclampsia/eclampsia and discharged in 2001.

DESIGN

Analyses were performed using a statewide hospital discharge dataset from Florida. Hospital discharge rates per Florida female population and risk per 100 deliveries were calculated for women hospitalized for preeclampsia. Binomial regression was used to calculate relative risks (RR) of PLOS among 5495 women. Generalized estimating equations were used to account for nesting by facility.

RESULTS

Non-Whites had higher preeclampsia discharge rates per 10,000 population than Whites in every age group. The overall risk of preeclampsia was 3.9 per 100 deliveries, with the highest risks in the youngest and oldest age groups. The strongest risk factor for PLOS was having a diagnosis of preeclampsia/eclampsia superimposed on pre-existing hypertension. These patients had 2.64 times the risk of PLOS than patients who had mild or unspecified preeclampsia (P value <.0001). Diabetics were also at a higher risk of PLOS (adjusted RR=1.26, P=.003). Women who were admitted from the emergency department were 26% less likely than women admitted from other sources to have PLOS (adjusted RR=.74, P=.01). For every 10-year increase in maternal age, there was a 23% increase in the risk of PLOS (adjusted RR=1.23, P<.0001).

CONCLUSIONS

Advancing maternal age, Black race, diabetes, severe preeclampsia, and preeclampsia (or eclampsia) superimposed on existing hypertension increased the risk of PLOS, while being admitted from the emergency department was associated with a decreased risk of PLOS.

Racial disparity in hypertensive disorders of pregnancy in New York State: a 10-year longitudinal population-based study

OBJECTIVES

We studied trends of hypertensive disorders of pregnancy by residential socioeconomic status (SES) and racial/ethnic subgroups in New York State over a 10-year period.

METHODS

We merged New York State discharge data for 2.5 million women hospitalized with delivery from 1993 through 2002 with 2000 US Census data.

RESULTS

Rates of diagnoses for all hypertensive disorders combined and for preeclampsia individually were highest among Black women across all regions and neighborhood poverty levels. Although hospitalization rates for preeclampsia decreased over time for most groups, differences in rates between White and Black women increased over the 10-year period. The proportion of women living in poor areas remained relatively constant over the same period. Black and Hispanic women were more likely than White women to have a form of diabetes and were at higher risk of preeclampsia; preeclampsia rates were higher in these groups both with and without diabetes than in corresponding groups of White women.

CONCLUSIONS

An increasing trend of racial/ethnic disparity in maternal hypertension rates occurred in New York State during the past decade. This trend was persistent after stratification according to SES and other risk factors. Additional research is needed to understand the factors contributing to this growing disparity.

Pregnancy-related mortality from preeclampsia and eclampsia

OBJECTIVE

To examine the role of preeclampsia and eclampsia in pregnancy-related mortality.

METHODS

We used data from the Centers for Disease Control and Prevention's Pregnancy Mortality Surveillance System to examine pregnancy-related deaths from preeclampsia and eclampsia from 1979 to 1992. The pregnancy-related mortality ratio for preeclampsia-eclampsia was defined as the number of deaths from preeclampsia and eclampsia per 100,000 live births. Case-fatality rates for 1988-1992 were calculated for preeclampsia and eclampsia deaths per 10,000 cases during the delivery hospitalization, using the National Hospital Discharge Survey.

RESULTS

Of 4024 pregnancy-related deaths at 20 weeks' or more gestation in 1979-1992, 790 were due to preeclampsia or eclampsia (1.5 deaths/100,000 live births). Mortality from preeclampsia and eclampsia increased with increasing maternal age. The highest risk of death was at gestational age 20-28 weeks and after the first live birth. Black women were 3.1 times more likely to die from preeclampsia or eclampsia as white women. Women who had received no prenatal care had a higher risk of death from preeclampsia or eclampsia than women who had received any level of prenatal care. The overall preeclampsia-eclampsia case-fatality rate was 6.4 per 10,000 cases at delivery, and was twice as high for black women as for white women.

CONCLUSION

The continuing racial disparity in mortality from preeclampsia and eclampsia emphasizes the need to identify those differences that contribute to excess mortality among black women, and to develop specific interventions to reduce mortality from preeclampsia and eclampsia among all women.

Prothrombin G20210A mutation: is it associated with pre-eclampsia?

OBJECTIVE

A strong independent association between the prothrombin G20210A gene mutation and pre-eclampsia has been reported in an Italian population. This result was not confirmed in a subsequent study in a Dutch population. The objective of this study was to further test the hypothesis that the prothrombin G20210A mutation is associated with pre-eclampsia/eclampsia.

METHODS

Seventeen eclamptics and 67 pre-eclamptics were recruited from 34 multicase Australian/New Zealand families. An additional 105 unrelated pre-eclamptic/eclamptic women and 119 parous women were recruited as controls.

RESULTS

The overall incidence for the prothrombin G20210A gene mutation in the pre-eclamptic group was 3.6% (95% CI 1.2-8.2%) which was not significantly different from the control group 2.5% (95% CI 0.5-7.2%) (p = 0.73, OR 1.44, 95% CI 0.34-6.17).

CONCLUSION

This study provides little evidence of a significant relationship between the prothrombin G20210A gene mutation and pre-eclampsia. Based on our results, we do not recommend testing for the prothrombin G20210A mutation in the routine investigation of women with pre-eclampsia.

The influence of maternal hypertension on low birth weight: differences among ethnic populations

OBJECTIVE

To determine the influence of maternal hypertension on the risk of low birth weight among white, black, and Hispanic residents of New York City.

METHODS

New York City birth certificates, 1988 through 1994, provided data on maternal and infant characteristics. Hypertension was self-reported on birth certificates, and was categorized as chronic or pregnancy-related hypertension. The complication of preeclampsia/eclampsia was also noted. The risk of low birth weight (<2500 grams) for maternal hypertension was determined.

RESULTS

The prevalence of hypertension during pregnancy was 3.8% overall, and was highest for blacks and lowest for whites. Low birth weight rates for white, black, and Hispanic babies were 5.0%, 12.8%, and 7.5%, respectively. Low birth weight rates among hypertensive mothers for whites, blacks and Hispanics were 16.8%, 24.4% and 19.5% respectively. The trends were similar for chronic and pregnancy-related hypertension, as well as for preeclampsia/eclampsia. The relative risk of low birth weight offspring among all hypertensive mothers was highest among whites (3.58, 95% CI = 3.39-3.79), and lowest among blacks (1.99, 95% CI = 1.93-2.06). This trend persisted for chronic and pregnancy-related hypertensive mothers, and those with preeclampsia/eclampsia, after adjusting for other maternal socioeconomic characteristics. Due to the higher prevalence of hypertension among black mothers, the population attributable risk of low birth weight was highest among black babies (557 per 100,000 live births) and lowest among whites (309 per 100,000 live births).

CONCLUSION

Maternal hypertension is an important risk factor for low birth weight. Its impact, however, differed by race/ethnicity groups.

Maternal hypertension and spontaneous preterm births among black women

OBJECTIVE

To examine effects of maternal hypertension on spontaneous preterm birth (birth at less than 37 weeks' gestation) among black women.

METHODS

Using hospital discharge summary records from the National Hospital Discharge Survey between 1988 and 1993, we conducted a case-control study to assess the risk of spontaneous preterm birth among black women with chronic hypertension preceding pregnancy and pregnancy-induced hypertension. Logistic regression was used to derive odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Preterm births were almost two times more likely for women with pregnancy-induced hypertension (OR = 1.8; 95% CI, 1.5, 2.2), more than 1.5 times more likely for women with chronic hypertension preceding pregnancy (OR = 1.6; 95% CI, 1.3, 2.1), and more than four times more likely for women with pregnancy-aggravated hypertension (OR = 4.4; 95% CI, 2.9, 6.7) compared with normotensive women. Preterm births also were associated significantly with antepartum hemorrhage, poor fetal growth, marital status, and source of payment. The odds of preterm birth by maternal hypertension were increased among women with chronic hypertension and genitourinary infection, whereas the odds of preterm birth were reduced among women with pregnancy-induced hypertension and genitourinary infection.

CONCLUSION

These findings are important in demonstrating the relation between type of hypertension in pregnancy and preterm birth. The relationships between maternal hypertension and preterm birth need to be further investigated to provide some guidelines in the management of hypertension in pregnancy and assessment of prenatal care compliance for black women, particularly when genitourinary infection is present.

Perceived causes of eclampsia in four ethnic groups in Borno State, Nigeria

This study was conducted among the four major ethnic groups(Kanuri, Babur, Shuwa and Marghi) of Borno State, North-east Nigeria. The aim of the study was to identify the perceived causes of eclampsia, a leading cause of maternal death in the State. The data were obtained through focus group discussions (FGDs), questionnaires and in-depth interviews. A total of 16 FGDs and 1,167 questionnaire interviews were conducted among the rural populace. In-depth interviews were conducted on relatives of thirty eclamptic patients admitted to the University of Maiduguri Teaching Hospital. The findings revealed that evil spirits/witches and wizards, poor nutrition, heredity early marriage, destiny from God and machinations of co-wives are the perceived causes of eclampsia in the area. These perceptions result in the use of the following as means of treatment: drinks of various concoctions, inhalation of smoked herbs in rooms, potash drinks, and the wearing of talisman around the neck. These perceptions and traditional medications have implications for design of educational and informational messages aimed at reducing maternal mortality from eclampsia in Borno State.

Eclampsia in Kuwait 1981-1993

The aim of this study is to investigate the maternal and fetal outcome and the risk factors for developing eclampsia in Kuwait. The study includes all patients with eclampsia observed at the Maternity Hospital, Kuwait during the period from 1981 to 1993. It revealed that the risk factors predisposing to eclampsia were primiparity, a maternal age below 30 years, multiple pregnancy and the presence of preeclampsia. The pregnancy outcome in terms of the stillbirth rate, neonatal death rate and low birth-weight babies was significantly higher in mothers with eclampsia than in noneclamptic mothers. The operative delivery and maternal mortality rates were also significantly higher in these patients.

Epidemiology of preeclampsia and eclampsia in the United States, 1979-1986

Preeclampsia and eclampsia continue to be among the leading causes of maternal death. However, national estimates of the occurrence of these conditions have not been available. To derive national rates of preeclampsia and eclampsia and to characterize the women at highest risk of the development of these conditions, we analyzed data from the National Hospital Discharge Survey for the years 1979 through 1986. We found that 26 per 1000 births during this period were complicated by preeclampsia and 0.56 per 1000 births were complicated by eclampsia. The rate of mild or unspecified preeclampsia remained constant over the study period. In contrast, the rate of severe preeclampsia increased sharply and the rate of eclampsia declined by 36%. Maternal age less than 20 years old was the strongest risk factor for both preeclampsia and eclampsia. These data indicate a need for improved prenatal care among teenagers.