IMPORTANCE: In an ideal regionalized system, all infants born very preterm would be delivered at a large tertiary hospital capable of providing all necessary care.

OBJECTIVE: To examine whether the distribution of extremely preterm births changed between 2009 and 2020 based on neonatal intensive care resources at the delivery hospital.

DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study was conducted at 822 Vermont Oxford Network (VON) centers in the US between 2009 and 2020. Participants included infants born at 22 to 29 weeks' gestation, delivered at or transferred to centers participating in the VON. Data were analyzed from February to December 2022.

EXPOSURES: Hospital of birth at 22 to 29 weeks' gestation.

MAIN OUTCOMES AND MEASURES: Birthplace neonatal intensive care unit (NICU) level was classified as A, restriction on assisted ventilation or no surgery; B, major surgery; or C, cardiac surgery requiring bypass. Level B centers were further divided into low-volume (<50 inborn infants at 22 to 29 weeks' gestation per year) and high-volume (≥50 inborn infants at 22 to 29 weeks' gestation per year) centers. High-volume level B and level C centers were combined, resulting in 3 distinct NICU categories: level A, low-volume B, and high-volume B and C NICUs. The main outcome was the change in the percentage of births at hospitals with level A, low-volume B, and high-volume B or C NICUs overall and by US Census region.

RESULTS: A total of 357 181 infants (mean [SD] gestational age, 26.4 [2.1] weeks; 188 761 [52.9%] male) were included in the analysis. Across regions, the Pacific (20 239 births [38.3%]) had the lowest while the South Atlantic (48 348 births [62.7%]) had the highest percentage of births at a hospital with a high-volume B- or C-level NICU. Births at hospitals with A-level NICUs increased by 5.6% (95% CI, 4.3% to 7.0%), and births at low-volume B-level NICUs increased by 3.6% (95% CI, 2.1% to 5.0%), while births at hospitals with high-volume B- or C-level NICUs decreased by 9.2% (95% CI, -10.3% to -8.1%). By 2020, less than half of the births for infants at 22 to 29 weeks' gestation occurred at hospitals with high-volume B- or C-level NICUs. Most US Census regions followed the nationwide trends; for example, births at hospitals with high-volume B- or C-level NICUs decreased by 10.9% [95% CI, -14.0% to -7.8%) in the East North Central region and by 21.1% (95% CI, -24.0% to -18.2%) in the West South Central region.

CONCLUSIONS AND RELEVANCE: This retrospective cohort study identified concerning deregionalization trends in birthplace hospital level of care for infants born at 22 to 29 weeks' gestation. These findings should serve to encourage policy makers to identify and enforce strategies to ensure that infants at the highest risk of adverse outcomes are born at the hospitals where they have the best chances to attain optimal outcomes.

IMPORTANCE: In an ideal regionalized system, all infants born very preterm would be delivered at a large tertiary hospital capable of providing all necessary care.

OBJECTIVE: To examine whether the distribution of extremely preterm births changed between 2009 and 2020 based on neonatal intensive care resources at the delivery hospital.

DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study was conducted at 822 Vermont Oxford Network (VON) centers in the US between 2009 and 2020. Participants included infants born at 22 to 29 weeks' gestation, delivered at or transferred to centers participating in the VON. Data were analyzed from February to December 2022.

EXPOSURES: Hospital of birth at 22 to 29 weeks' gestation.

MAIN OUTCOMES AND MEASURES: Birthplace neonatal intensive care unit (NICU) level was classified as A, restriction on assisted ventilation or no surgery; B, major surgery; or C, cardiac surgery requiring bypass. Level B centers were further divided into low-volume (<50 inborn infants at 22 to 29 weeks' gestation per year) and high-volume (≥50 inborn infants at 22 to 29 weeks' gestation per year) centers. High-volume level B and level C centers were combined, resulting in 3 distinct NICU categories: level A, low-volume B, and high-volume B and C NICUs. The main outcome was the change in the percentage of births at hospitals with level A, low-volume B, and high-volume B or C NICUs overall and by US Census region.

RESULTS: A total of 357 181 infants (mean [SD] gestational age, 26.4 [2.1] weeks; 188 761 [52.9%] male) were included in the analysis. Across regions, the Pacific (20 239 births [38.3%]) had the lowest while the South Atlantic (48 348 births [62.7%]) had the highest percentage of births at a hospital with a high-volume B- or C-level NICU. Births at hospitals with A-level NICUs increased by 5.6% (95% CI, 4.3% to 7.0%), and births at low-volume B-level NICUs increased by 3.6% (95% CI, 2.1% to 5.0%), while births at hospitals with high-volume B- or C-level NICUs decreased by 9.2% (95% CI, -10.3% to -8.1%). By 2020, less than half of the births for infants at 22 to 29 weeks' gestation occurred at hospitals with high-volume B- or C-level NICUs. Most US Census regions followed the nationwide trends; for example, births at hospitals with high-volume B- or C-level NICUs decreased by 10.9% [95% CI, -14.0% to -7.8%) in the East North Central region and by 21.1% (95% CI, -24.0% to -18.2%) in the West South Central region.

CONCLUSIONS AND RELEVANCE: This retrospective cohort study identified concerning deregionalization trends in birthplace hospital level of care for infants born at 22 to 29 weeks' gestation. These findings should serve to encourage policy makers to identify and enforce strategies to ensure that infants at the highest risk of adverse outcomes are born at the hospitals where they have the best chances to attain optimal outcomes.

BACKGROUND: In contrast to other high-resource countries, the United States has experienced increases in the rates of severe maternal morbidity. In addition, the United States has pronounced racial and ethnic disparities in severe maternal morbidity, especially for non-Hispanic Black people, who have twice the rate as non-Hispanic White people.

OBJECTIVE: This study aimed to examine whether the racial and ethnic disparities in severe maternal morbidity extended beyond the rates of these complications to include disparities in maternal costs and lengths of stay, which could indicate differences in the case severity.

STUDY DESIGN: This study used California's linkage of birth certificates to inpatient maternal and infant discharge data for 2009 to 2011. Of the 1.5 million linked records, 250,000 were excluded because of incomplete data, for a final sample of 1,262,862. Cost-to-charge ratios were used to estimate costs from charges (including readmissions) after adjusting for inflation to December 2017. Mean diagnosis-related group-specific reimbursement was used to estimate physician payments. We used the Centers for Disease Control and Prevention definition of severe maternal morbidity, including readmissions up to 42 days after delivery. Adjusted Poisson regression models estimated the differential risk of severe maternal morbidity for each racial or ethnic group, compared with the non-Hispanic White group. Generalized linear models estimated the associations of race and ethnicity with costs and length of stay.

RESULTS: Asian or Pacific Islander, Non-Hispanic Black, Hispanic, and other race or ethnicity patients all had higher rates of severe maternal morbidity than non-Hispanic White patients. The largest disparity was between non-Hispanic White and non-Hispanic Black patients, with unadjusted overall rates of severe maternal morbidity of 1.34% and 2.62%, respectively (adjusted risk ratio, 1.61; P<.001). Among patients with severe maternal morbidity, the adjusted regression estimates showed that non-Hispanic Black patients had 23% (P<.001) higher costs (marginal effect of $5023) and 24% (P<.001) longer hospital stays (marginal effect of 1.4 days) than non-Hispanic White patients. These effects changed when cases, such as cases where a blood transfusion was the only indication of severe maternal morbidity, were excluded, with 29% higher costs (P<.001) and 15% longer length of stay (P<.001). For other racial and ethnic groups, the increases in costs and length of stay were smaller than those observed for non-Hispanic Black patients, and many were not significantly different from non-Hispanic White patients. Hispanic patients had higher rates of severe maternal morbidity than non-Hispanic White patients; however, Hispanic patients had significantly lower costs and length of stay than non-Hispanic White patients.

CONCLUSION: There were racial and ethnic differences in the costs and length of stay among patients with severe maternal morbidity across the groupings that we examined. The differences were especially large for non-Hispanic Black patients compared with non-Hispanic White patients. Non-Hispanic Black patients experienced twice the rate of severe maternal morbidity; in addition, the higher relative costs and longer lengths of stay for non-Hispanic Black patients with severe maternal morbidity support greater case severity in that population. These findings suggest that efforts to address racial and ethnic inequities in maternal health need to consider differences in case severity in addition to the differences in the rates of severe maternal morbidity and that these differences in case severity merit additional investigation.

BACKGROUND: In contrast to other high-resource countries, the United States has experienced increases in the rates of severe maternal morbidity. In addition, the United States has pronounced racial and ethnic disparities in severe maternal morbidity, especially for non-Hispanic Black people, who have twice the rate as non-Hispanic White people.

OBJECTIVE: This study aimed to examine whether the racial and ethnic disparities in severe maternal morbidity extended beyond the rates of these complications to include disparities in maternal costs and lengths of stay, which could indicate differences in the case severity.

STUDY DESIGN: This study used California's linkage of birth certificates to inpatient maternal and infant discharge data for 2009 to 2011. Of the 1.5 million linked records, 250,000 were excluded because of incomplete data, for a final sample of 1,262,862. Cost-to-charge ratios were used to estimate costs from charges (including readmissions) after adjusting for inflation to December 2017. Mean diagnosis-related group-specific reimbursement was used to estimate physician payments. We used the Centers for Disease Control and Prevention definition of severe maternal morbidity, including readmissions up to 42 days after delivery. Adjusted Poisson regression models estimated the differential risk of severe maternal morbidity for each racial or ethnic group, compared with the non-Hispanic White group. Generalized linear models estimated the associations of race and ethnicity with costs and length of stay.

RESULTS: Asian or Pacific Islander, Non-Hispanic Black, Hispanic, and other race or ethnicity patients all had higher rates of severe maternal morbidity than non-Hispanic White patients. The largest disparity was between non-Hispanic White and non-Hispanic Black patients, with unadjusted overall rates of severe maternal morbidity of 1.34% and 2.62%, respectively (adjusted risk ratio, 1.61; P<.001). Among patients with severe maternal morbidity, the adjusted regression estimates showed that non-Hispanic Black patients had 23% (P<.001) higher costs (marginal effect of $5023) and 24% (P<.001) longer hospital stays (marginal effect of 1.4 days) than non-Hispanic White patients. These effects changed when cases, such as cases where a blood transfusion was the only indication of severe maternal morbidity, were excluded, with 29% higher costs (P<.001) and 15% longer length of stay (P<.001). For other racial and ethnic groups, the increases in costs and length of stay were smaller than those observed for non-Hispanic Black patients, and many were not significantly different from non-Hispanic White patients. Hispanic patients had higher rates of severe maternal morbidity than non-Hispanic White patients; however, Hispanic patients had significantly lower costs and length of stay than non-Hispanic White patients.

CONCLUSION: There were racial and ethnic differences in the costs and length of stay among patients with severe maternal morbidity across the groupings that we examined. The differences were especially large for non-Hispanic Black patients compared with non-Hispanic White patients. Non-Hispanic Black patients experienced twice the rate of severe maternal morbidity; in addition, the higher relative costs and longer lengths of stay for non-Hispanic Black patients with severe maternal morbidity support greater case severity in that population. These findings suggest that efforts to address racial and ethnic inequities in maternal health need to consider differences in case severity in addition to the differences in the rates of severe maternal morbidity and that these differences in case severity merit additional investigation.

BACKGROUND: In contrast to other high-resource countries, the US has experienced increases in the rates of severe maternal morbidity. The US also has pronounced racial/ethnic disparities in severe maternal morbidity, especially for non-Hispanic Black people, who have twice the rate as non-Hispanic White people.

OBJECTIVE(S): The objective of this study was to examine if the racial/ethnic disparities in severe maternal morbidity extended beyond the rates of these complications to include disparities in maternal costs and lengths of stay, which could indicate differences in the case severity.

STUDY DESIGN: This study used California's linkage of birth certificates to inpatient maternal and infant discharge data for 2009-2011. Of the 1.5 million linked records, 250,000 were excluded due to incomplete data, for a final sample of 1,262,862. Cost-to-charge ratios were used to estimate costs from charges (including readmissions) after adjusting for inflation to December 2017. Mean diagnostic-related group-specific reimbursement was used to estimate physician payments. We used the Centers for Disease Control and Prevention definition of severe maternal morbidity, including readmissions up to 42 days postpartum. Adjusted Poisson regression models estimated the differential risk of severe maternal morbidity for each racial/ethnic group, compared with the non-Hispanic White group. Generalized linear models estimated the associations of race/ethnicity with costs and length of stay.

RESULTS: Asian/Pacific Islander, Non-Hispanic Black, Hispanic, and Other race/ethnicity patients all had higher rates of severe maternal morbidity than non-Hispanic White patients. The largest disparity was between non-Hispanic White and non-Hispanic Black patients, with unadjusted overall rates of severe maternal morbidity of 1.34% and 2.62%, respectively (adjusted risk ratio 1.61, p<0.001). Among patients with severe maternal morbidity, the adjusted regression estimates showed that non-Hispanic Black patients had 23% (p<0.001) higher costs (marginal effect $5,023) and 24% (p<0.001) longer hospital stays (marginal effect 1.4 days) compared to non-Hispanic White patients. These effects changed when cases where a blood transfusion was the only indication of severe maternal morbidity were excluded, with 29% higher costs (p<0.001) and 15% longer length of stay (p<0.001). For other racial/ethnic groups, the increases in costs and length of stay were smaller than those observed for non-Hispanic Black patients, and many were not significant different from non-Hispanic White patients. Hispanic patients had higher rates of severe maternal morbidity than non-Hispanic White patients but significantly lower costs and length of stay.

CONCLUSION(S): There were racial/ethnic differences in the costs and length of stay among patients with severe maternal morbidity across the groupings that we examined. The differences were especially large for non-Hispanic Black patients compared with non-Hispanic White patients. Non-Hispanic Black patients experienced twice the rate of severe maternal morbidity; additionally, the higher relative costs and longer lengths of stay for non-Hispanic Black patients with severe maternal morbidity supports greater case severity in that population. These findings suggest that efforts to address racial/ethnic inequities in maternal health need to consider differences in case severity in addition to the differences in the rates of severe maternal morbidity and that these differences in case severity merit additional investigation.

<p><strong>OBJECTIVE: </strong>To examine the association between severe maternal morbidity (SMM) and infant health using the additional infant costs and length of stay (LOS) as markers of added clinical complexity.</p>

<p><strong>STUDY DESIGN: </strong>Secondary data analysis using California linked birth certificate-patient discharge data for 2009-2011 (N = 1,260,457). Regression models were used to estimate the association between SMM and infant costs and LOS.</p>

<p><strong>RESULTS: </strong>The 16,687 SMM-exposed infants experienced a $6550 (33%) increase in costs and a 0.7 (18%) day increase in LOS. Preterm infants had ($11,258 (18%) added costs and 1.3 days (8.1%) longer LOS) than term infants ($2539 (38%) added costs and 0.5 days (22%) longer LOS).</p>

<p><strong>CONCLUSIONS: </strong>SMM was associated with increased infant costs and LOS, suggesting that SMM may have adverse health effects for infants, including term infants. The relatively larger effect on costs indicates an increase in treatment intensity (clinical severity) greater than additional LOS.</p>

<p><strong>INTRODUCTION: </strong>The objectives of this study were to include readmissions and physician costs in the estimates of total costs of severe maternal morbidity (SMM), to consider the effect of SMM on maternal length of stay (LOS), and to examine these for the more restricted definition of SMM that excludes transfusion-only cases.</p>

<p><strong>METHODS: </strong>California linked birth certificate-patient discharge data for 2009 through 2011 (n&nbsp;=&nbsp;1,262,862) with complete costs and LOS were used in a secondary data analysis. Cost-to-charge ratios were used to estimate costs from charges, adjusting for inflation. Physician payments were estimated from the mean payments for specific diagnosis-related groups. Generalized linear models estimated the association between SMM and costs and LOS.</p>

<p><strong>RESULTS: </strong>Excluding readmissions and physician costs, SMM was associated with a 60% increase in hospital costs (marginal effect [ME], $3,550) and a 33% increase in LOS (ME 0.9&nbsp;days). These increased to 70% (ME $5,806) and 46% (ME 1.3&nbsp;days) when physician costs and readmissions were included. The effects of SMM were roughly one-half as large for patients who only required a blood transfusion (49% [ME $4,056] and 31% [ME 0.9&nbsp;days]) as for patients who had another indicator for SMM (93% [ME $7,664] and 62% [ME 1.7&nbsp;days]).</p>

<p><strong>CONCLUSIONS: </strong>Postpartum hospital readmissions and physician costs are important and previously unreported contributors to the costs of SMM. Excess costs and LOS associated with SMM vary considerably by indication. Cost effects were larger than the LOS effects, indicating that SMM increases treatment intensity beyond increasing LOS, and decreasing SMM may have broader health and cost benefits than previously understood.</p>

<p><strong>OBJECTIVE: </strong>To examine the relative contributions of preterm delivery and congenital anomalies to neonatal mortality.</p>

<p><strong>STUDY DESIGN: </strong>Retrospective analysis of 2009-2011 linked birth cohort-hospital discharge files for California, Missouri, Pennsylvania and South Carolina. Deaths were classified by gestational age and three definitions of congenital anomaly: any ICD-9 code for an anomaly, any anomaly with a significant mortality risk, and anomalies recorded on the death certificate.</p>

<p><strong>RESULT: </strong>In total, 59% of the deaths had an ICD-9 code for an anomaly, only 43% had a potentially fatal anomaly, and only 34% had a death certificate anomaly. Preterm infants (&lt;37 weeks GA) accounted for 80% of deaths; those preterm infants without a potentially fatal anomaly diagnosis comprised 53% of all neonatal deaths. The share of preterm deaths with a potentially fatal anomaly decreases with GA.</p>

<p><strong>CONCLUSION: </strong>Congenital anomalies are responsible for about 40% of neonatal deaths while preterm without anomalies are responsible for over 50%.</p>

<p><strong>Importance: </strong>Timely access to clinically appropriate obstetric services is critical to the provision of high-quality perinatal care.</p>

<p><strong>Objective: </strong>To examine the geographic distribution, proximity, and urban adjacency of US obstetric hospitals by annual birth volume.</p>

<p><strong>Design, Setting, and Participants: </strong>This retrospective population-based cohort study identified US hospitals with obstetric services using the American Hospital Association (AHA) Annual Survey of Hospitals and Centers for Medicare &amp; Medicaid provider of services data from 2010 to 2018. Obstetric hospitals with 10 or more births per year were included in the study. Data analysis was performed from November 6, 2020, to April 5, 2021.</p>

<p><strong>Exposure: </strong>Hospital birth volume, defined by annual birth volume categories of 10 to 500, 501 to 1000, 1001 to 2000, and more than 2000 births.</p>

<p><strong>Main Outcomes and Measures: </strong>Outcomes assessed by birth volume category were percentage of births (from annual AHA data), number of hospitals, geographic distribution of hospitals among states, proximity between obstetric hospitals, and urban adjacency defined by urban influence codes, which classify counties by population size and adjacency to a metropolitan area.</p>

<p><strong>Results: </strong>The study included 26 900 hospital-years of data from 3207 distinct US hospitals with obstetric services, reflecting 34 054 951 associated births. Most infants (19 327 487 [56.8%]) were born in hospitals with more than 2000 births/y, and 2 528 259 (7.4%) were born in low-volume (10-500 births/y) hospitals. More than one-third of obstetric hospitals (37.4%; 10 064 hospital-years) were low volume. A total of 46 states had obstetric hospitals in all volume categories. Among low-volume hospitals, 18.9% (1904 hospital-years) were not within 30 miles of any other obstetric hospital and 23.9% (2400 hospital-years) were within 30 miles of a hospital with more than 2000 deliveries/y. Isolated hospitals (those without another obstetric hospital within 30 miles) were more frequently low volume, with 58.4% (1112 hospital-years) located in noncore rural areas.</p>

<p><strong>Conclusions and Relevance: </strong>In this cohort study, marked variations were found in birth volume, geographic distribution, proximity, and urban adjacency among US obstetric hospitals from 2010 to 2018. The findings related to geographic isolation and rural-urban distribution of low-volume obstetric hospitals suggest the need to balance proximity with volume to optimize effective referral and access to high-quality perinatal care.</p>

<p>Variations in infant and neonatal mortality continue to persist in the United States and in other countries based on both socio-demographic characteristics, such as race and ethnicity, and geographic location. One potential driver of these differences is variations in access to risk-appropriate delivery care. The purpose of this article is to present the&nbsp;importance of delivery hospitals on neonatal outcomes, discuss variation in access to these hospitals for high-risk infants and their mothers, and to provide insight into drivers for differences in access to high-quality perinatal care using the available literature.&nbsp;This review also illustrates the lack of information on a number of topics that are crucial to the development of evidence-based interventions to improve access to appropriate delivery hospital services and thus optimize the outcomes of high-risk mothers and their newborns.</p>