Socioeconomic disadvantage and racial/ethnic disparities in low-risk cesarean birth in California.

Our objective was to assess the relationship of socioeconomic disadvantage and race/ethnicity with low-risk cesarean birth. We examined birth certificates (2007-18) linked with maternal hospitalization data from California; the outcome was cesarean birth among low-risk deliveries (i.e., nulliparous, term, singleton, vertex [NTSV]). We used GEE Poisson regression with an interaction term for race/ethnicity (7 groups) and a measure of socioeconomic disadvantage (census tract-level neighborhood deprivation index [NDI], education, or insurance). Among 1,815,933 NTSV births, 26.6% were cesarean. When assessing the joint effect of race/ethnicity and socioeconomic disadvantage among low-risk births, risk of cesarean birth increased with socioeconomic disadvantage for most racial/ethnic groups, and disadvantaged Black individuals had the highest risks; e.g., Black individuals with a high school education or less had a risk ratio of 1.49 (95% CI 1.45-1.53), relative to White individuals with a college degree. The disparity in risk of cesarean birth between Black and White individuals was observed across all strata of socioeconomic disadvantage. Asian American and Hispanic individuals had higher risks than White individuals at lower socioeconomic disadvantage; this disparity was not observed at higher levels of disadvantage. Black individuals have a persistent, elevated risk of cesarean birth, relative to White individuals, regardless of socioeconomic disadvantage.

Using Longitudinally Linked Data to Measure Severe Maternal Morbidity Beyond the Birth Hospitalization in California.

Most studies of severe maternal morbidity (SMM) include only cases that occur during birth hospitalizations. We examined the increase in cases when including SMM during antenatal and postpartum (within 42 days of discharge) hospitalizations, using longitudinally linked data from 1,010,250 births in California from September 1, 2016, to December 31, 2018. For total SMM, expanding the definition resulted in 22.8% more cases; for nontransfusion SMM, 45.1% more cases were added. Sepsis accounted for 55.5% of the additional cases. The increase varied for specific indicators, for example, less than 2% for amniotic fluid embolism, 7.0% for transfusion, 112.9% for sepsis, and 155.6% for acute myocardial infarction. These findings reiterate the importance of considering SMM beyond just the birth hospitalization and facilitating access to longitudinally linked data to facilitate a more complete understanding of SMM.

Association of Gestational Age with Postpartum Hemorrhage: An International Cohort Study.

BACKGROUND: Risk factors for postpartum hemorrhage, such as chorioamnionitis and multiple gestation, have been identified in previous epidemiologic studies. However, existing data describing the association between gestational age at delivery and postpartum hemorrhage are conflicting. The aim of this study was to assess the association between gestational age at delivery and postpartum hemorrhage. METHODS: The authors conducted a population-based retrospective cohort study of women who underwent live birth delivery in Sweden between 2014 and 2017 and in California between 2011 and 2015. The primary exposure was gestational age at delivery. The primary outcome was postpartum hemorrhage, classified using International Classification of Diseases, Ninth Revision-Clinical Modification codes for California births and a blood loss greater than 1,000 ml for Swedish births. The authors accounted for demographic and obstetric factors as potential confounders in the analyses. RESULTS: The incidences of postpartum hemorrhage in Sweden (23,323/328,729; 7.1%) and in California (66,583/2,079,637; 3.2%) were not comparable. In Sweden and California, the incidence of postpartum hemorrhage was highest for deliveries between 41 and 42 weeks' gestation (7,186/75,539 [9.5%] and 8,921/160,267 [5.6%], respectively). Compared to deliveries between 37 and 38 weeks, deliveries between 41 and 42 weeks had the highest adjusted odds of postpartum hemorrhage (1.62 [95% CI, 1.56 to 1.69] in Sweden and 2.04 [95% CI, 1.98 to 2.09] in California). In both cohorts, the authors observed a nonlinear (J-shaped) association between gestational age and postpartum hemorrhage risk, with 39 weeks as the nadir. In the sensitivity analyses, similar findings were observed among cesarean deliveries only, when postpartum hemorrhage was classified only by International Classification of Diseases, Tenth Revision-Clinical Modification codes, and after excluding women with abnormal placentation disorders. CONCLUSIONS: The postpartum hemorrhage incidence in Sweden and California was not comparable. When assessing a woman's risk for postpartum hemorrhage, clinicians should be aware of the heightened odds in women who deliver between 41 and 42 weeks' gestation.

Confirmed severe maternal morbidity is associated with high rate of preterm delivery.

BACKGROUND: Because severe maternal morbidity (SMM) is increasing in the United States, affecting up to 50,000 women per year, there was a recent call to review all mothers with SMM to better understand their morbidity and improve outcomes. Administrative screening methods for SMM have recently been shown to have low positive predictive value for true SMM after chart review. To ultimately reduce maternal morbidity and mortality we must better understand risk factors, and preventability issues about true SMM such that interventions could be designed to improve care. OBJECTIVE: Our objective was to determine risk factors associated with true SMM identified from California delivery admissions, including the relationship between SMM and preterm delivery. STUDY DESIGN: In this retrospective cohort study, SMM cases were screened for using International Classification of Diseases, Ninth Revision codes for severe illness and procedures, prolonged postpartum length of stay, intensive care unit admission, and transfusion from all deliveries in 16 hospitals from July 2012 through June 2013. Charts of screen-positive cases were reviewed and true SMM diagnosed based on expert panel agreement. Underlying disease diagnosis was determined. Women with true-positive SMM were compared to SMM-negative women for the following variables: maternal age, ethnicity, gestational age at delivery, prior cesarean delivery, and multiple gestation. RESULTS: In all, 491 women had true SMM and 66,977 women did not have SMM for a 0.7% rate of true SMM. Compared to SMM-negative women, SMM cases were significantly more likely to be age >35 years (33.6 vs 23.8%; P < .0001), be African American (14.1 vs 7.9%; P < .0001), have had a multiple gestation (9.7 vs 2.1%; P < .0001), and, for the multiparous women, have had a prior cesarean delivery (58 vs 30.2%; P < .0001). Preterm delivery was significantly more common in SMM women compared to SMM-negative women (41 vs 8%; P < .0001), including delivery <32 weeks (18 vs 2%; P < .0001). The most common underlying disease was obstetric hemorrhage (42%) followed by hypertensive disorders (20%) and placental hemorrhage (14%). Only 1.6% of women with SMM had cardiovascular disease as the underlying disease category. CONCLUSION: An extremely high proportion of women with severe morbidity (42.5%) delivered preterm with 17.8% delivering <32 weeks, which underscores the importance of access to appropriate-level care for mothers with SMM and their newborns. Further, the extremely high rate of preterm delivery (75%) in women with placental hemorrhage in combination with their 63% prior cesarean delivery rate highlights another risk of prior cesarean delivery: subsequent preterm delivery. These data provide a reminder that a cesarean delivery could be a contributing factor to not only hemorrhage-related SMM, but also to increased subsequent preterm delivery, more reason to continue national efforts to safely reduce initial cesarean deliveries.

Severe maternal morbidity in a large cohort of women with acute severe intrapartum hypertension.

BACKGROUND: Hypertensive diseases of pregnancy are associated with severe maternal morbidity and remain common causes of maternal death. Recently, national guidelines have become available to aid in recognition and management of hypertension in pregnancy to reduce morbidity and mortality. The increased morbidity related to hypertensive disorders of pregnancy is presumed to be associated with the development of severe hypertension. However, there are few data on specific treatment or severe maternal morbidity in women with acute severe intrapartum hypertension as opposed to severe preeclampsia. OBJECTIVE: The study aimed to characterize maternal morbidity associated with women with acute severe intrapartum hypertension, and to determine whether there was an association between various first-line antihypertensive agents and posttreatment blood pressure. STUDY DESIGN: This retrospective cohort study of women delivering between July 2012 and August 2014 at 15 hospitals participating in the California Maternal Quality Care Collaborative compared women with severe intrapartum hypertension (systolic blood pressure >160 mm Hg or diastolic blood pressure >105 mm Hg) to women without severe hypertension. Hospital Patient Discharge Data and State of California Birth Certificate Data were used. Severe maternal morbidity using the Centers for Disease Control and Prevention criteria based on International Classification of Diseases-9 codes was compared between groups. The efficacy of different antihypertensive medications in meeting the 1-hour posttreatment goal was determined. Statistical methods included distribution appropriate univariate analyses and multivariate logistic regression. RESULTS: There were 2252 women with acute severe intrapartum hypertension and 93,650 women without severe hypertension. Severe maternal morbidity was significantly more frequent in the women with severe hypertension (8.8%) compared to the control women (2.3%) (P < .0001). Severe maternal morbidity rates did not increase with increasing severity of blood pressures (P = .90 for systolic and .42 for diastolic). There was no difference in severe maternal morbidity between women treated (8.6%) and women not treated (9.5%) (P = .56). Antihypertensive treatment rates were significantly higher in hospitals with a level IV neonatal intensive care unit (85.8%) compared to a level III neonatal intensive care unit (80.2%) (P < .001), and in higher-volume hospitals (84.5%) compared to lower-volume hospitals (69.1%) (P < .001). Severe maternal morbidity rates among severely hypertensive women were significantly higher in hospitals with level III neonatal intensive care unit level compared to hospitals with a level IV neonatal intensive care unit (10.6% vs 5.7%, respectively; P < .001), and significantly higher in low-delivery volume hospitals compared to high-delivery volume hospitals (15.5% vs 7.6%, respectively; P < .001). Only 53% of women treated with oral labetalol as first-line medication met the posttreatment goal of nonsevere hypertension, significantly less than those treated with intravenous hydralazine, intravenous labetalol, or oral nifedipine (68%, 71%, and 82%, respectively) (P = .001). Severe intrapartum hypertension remained untreated in 17% of women. CONCLUSION: Women with acute severe intrapartum hypertension had a significantly higher risk of severe maternal morbidity compared to women without severe hypertension. Significantly lower antihypertensive treatment rates and higher severe maternal morbidity rates were seen in lower-delivery volume hospitals.

Increasing pre-pregnancy body mass index is predictive of a progressive escalation in adverse pregnancy outcomes.

OBJECTIVE: To evaluate the association between pre-pregnancy body mass index (BMI) and adverse pregnancy outcomes using a large administrative database. METHODS: Retrospective cohort study of California women delivering singletons in 2007. The association between pre-pregnancy BMI category and adverse outcomes were evaluated using multivariate logistic regression. RESULTS: Among 436,414 women, increasing BMI was associated with increasing odds of adverse outcomes. Obese women (BMI=30-39.9) were nearly 3 x more likely to have gestational diabetes (OR=2.83, 95% CI=2.74-2.92) and gestational hypertension/preeclampsia (2.68, 2.59-2.77) and nearly twice as likely to undergo cesarean (1.82, 1.78-1.87), when compared to normal BMI women (BMI=18.5-24.9). Morbidly obese women (BMI ≥ 40) were 4x more likely to have gestational diabetes (4.72, 4.46-4.99) and gestational hypertension/preeclampsia (4.22, 3.97-4.49) and nearly 3 x as likely to undergo cesarean (2.60, 2.46-2.74). CONCLUSION: There is a strong association between increasing maternal BMI and adverse pregnancy outcomes. This information is important for counseling women regarding the risks of obesity in pregnancy.