Individual and County-Level Factors Associated with Severe Maternal Morbidity at Delivery: An Investigation of a Privately Insured Population in the United States, 2008 to 2018

Abstract

Objective

Few studies have explored the impact of county-level variables on severe maternal morbidity (SMM) subtypes. To address this gap, this study used a large commercial database to examine the associations between individual- and county-level factors and SMM.

Study Design

This retrospective cohort study used data from the Optum's deidentified Clinformatics Data Mart Database from 2008 to 2018. The primary outcomes of this study were any SMM, nontransfusion SMM, and nine specific SMM subtypes. Temporal trends in the prevalence of SMM and SMM subtypes were assessed using Joinpoint Regression. Multilevel logistic regression models were used to investigate the association of individual- and county-level factors with SMM.

Results

Between 2008 and 2018, there was not a significant change in the prevalence of any SMM (annual percent change [APC]: −0.9, 95% confidence interval [CI]: −2.2, 0.5). Significant increases in prevalence were identified for three SMM subtypes: other obstetric (OB) SMM (APC: 10.3, 95% CI: 0.1, 21.5) from 2013 to 2018, renal SMM (APC: 8.5, 95% CI: 5.5, 11.6) from 2008 to 2018, and sepsis (APC: 23.0, 95% CI: 6.5, 42.1) from 2014 to 2018. Multilevel logistic regression models revealed variability in individual and county risk factors across different SMM subtypes. Adolescent mothers (odds ratio [OR]: 2.10, 95% CI: 1.29, 3.40) and women in the 40 to 55 (OR: 1.67, 95% CI: 1.12, 2.51) age group were found to be at significant risk of other OB SMM and renal SMM, respectively. For every increase in rank within a county's socioeconomic social vulnerability index (SVI), the risk of respiratory SMM increased 2.8-fold, whereas an increase in rank in the racial/ethnic minority SVI was associated with a 1.6-fold elevated risk of blood transfusion.

Conclusion

This study underscores the complex association between individual and county factors associated with SMM, emphasizing the need for multifaced approaches to improve maternal care.

Key Points

• No increase in composite SMM rates from 2008 to 2018.

• Increases in obstetric SMM subtypes and sepsis.

• Risk factor profiles may differ across SMM subtypes.

• Key risk factors: age, comorbidities, prenatal care.

• County socioeconomic status associated with respiratory SMM risk.

Keywords

severe maternal morbidity - maternal comorbidities - obstetric comorbidity index - maternal health - social vulnerability index

Publication History

Received: 08 August 2024

Accepted: 22 November 2024

Accepted Manuscript online:
25 November 2024

Article published online:
15 January 2025

• References

• 1 Centers for Disease Control and Prevention. Severe maternal morbidity in the United States. February 2, 2021. Accessed October 10, 2018 at: https://www.cdc.gov/reproductivehealth/maternalinfanthealth/severematernalmorbidity.html
• 2 Alliance for Innovation on Maternal Health. Aim data resources. Accessed November 24, 2020 at: https://saferbirth.org/aim-data/resources/
• 3 Carmichael SL, Abrams B, El Ayadi A. et al. Ways forward in preventing severe maternal morbidity and maternal health inequities: conceptual frameworks, definitions, and data, from a population health perspective. Women Health Issues 2021
• 4 Phibbs CM, Kozhimannil KB, Leonard SA. et al. A comprehensive analysis of the costs of severe maternal morbidity. Women Health Issues 2022; 32 (04) 362-368
• 5 Geller SE, Rosenberg D, Cox SM. et al. The continuum of maternal morbidity and mortality: factors associated with severity. Am J Obstet Gynecol 2004; 191 (03) 939-944
• 6 Fingar KR, Hambrick MM, Heslin KC, Moore JE. Trends and Disparities in Delivery Hospitalizations Involving Severe Maternal Morbidity, 2006–2015: Statistical Brief #243. Healthcare Cost and Utilization Project (HCUP) Statistical Briefs. Agency for Healthcare Research and Quality (United States); 2018
• 7 Metcalfe A, Wick J, Ronksley P. Racial disparities in comorbidity and severe maternal morbidity/mortality in the United States: an analysis of temporal trends. Acta Obstet Gynecol Scand 2018; 97 (01) 89-96
• 8 Brown CC, Adams CE, George KE, Moore JE. Associations between comorbidities and severe maternal morbidity. Obstet Gynecol 2020; 136 (05) 892-901
• 9 Korst LM, Gregory KD, Nicholas LA. et al. A scoping review of severe maternal morbidity: describing risk factors and methodological approaches to inform population-based surveillance. Matern Health Neonatol Perinatol 2021; 7 (01) 3
• 10 Howland RE, Angley M, Won SH. et al. Determinants of severe maternal morbidity and its racial/ethnic disparities in New York City, 2008-2012. Matern Child Health J 2019; 23 (03) 346-355
• 11 Kramer MR, Strahan AE, Preslar J. et al. Changing the conversation: applying a health equity framework to maternal mortality reviews. Am J Obstet Gynecol 2019; 221 (06) 609.e1-609.e9
• 12 Meeker JR, Canelón SP, Bai R, Levine LD, Boland MR. Individual-level and neighborhood-level risk factors for severe maternal morbidity. Obstet Gynecol 2021; 137 (05) 847-854
• 13 Guglielminotti J, Landau R, Wong CA, Li G. Patient-, hospital-, and neighborhood-level factors associated with severe maternal morbidity during childbirth: a cross-sectional study in New York State 2013-2014. Matern Child Health J 2019; 23 (01) 82-91
• 14 Office of Policy Development and Research. HUD USPS zip code crosswalk files. Accessed March 20, 2022 at: https://www.huduser.gov/portal/datasets/usps_crosswalk.html
• 15 Health Resources & Services Admistration. Area health resources files. Accessed March 3, 2021 at: https://data.hrsa.gov/topics/health-workforce/ahrf
• 16 Agency for Toxic Substances and Disease Registry. Agency for toxic substances and disease registry. Accessed March 11, 2024 at: https://www.atsdr.cdc.gov/index.html
• 17 County Health Rankings & Roadmaps. About us. Accessed April 24, 2021 at: https://www.countyhealthrankings.org/about-us
• 18 County Health Rankings and Roadmaps. 2021 Measures. Accessed August 9, 2021 at: https://www.countyhealthrankings.org/explore-health-rankings/measures-data-sources/2021-measures
• 19 Li Q, Andrade SE, Cooper WO. et al. Validation of an algorithm to estimate gestational age in electronic health plan databases. Pharmacoepidemiol Drug Saf 2013; 22 (05) 524-532
• 20 Leonard SA, Panelli DM, Gould JB, Gemmill A, Main EK. Validation of ICD-10-CM diagnosis codes for gestational age at birth. Epidemiology 2023; 34 (01) 64-68
• 21 Kern-Goldberger AR, Sheils NE, Ventura MEM. et al. Patterns of prenatal care delivery and obstetric outcomes before and during the COVID-19 pandemic. Am J Perinatol 2023; 40 (06) 582-588
• 22 Butwick AJ, Bentley J, Daw J. et al. Postpartum care visits among commercially insured women in the United States. AJOG Glob Rep 2022; 2 (04) 100106
• 23 Leonard SA, Main EK, Lyell DJ. et al. Obstetric comorbidity scores and disparities in severe maternal morbidity across marginalized groups. Am J Obstet Gynecol MFM 2022; 4 (02) 100530
• 24 Agency for Toxic Substances and Disease Registry. CDC SVI documentation 2018. Accessed October 22, 2023 at: https://www.atsdr.cdc.gov/placeandhealth/svi/documentation/SVI_documentation_2018.html
• 25 County Health Rankings and Roadmaps. Income inequality. Accessed July 30, 2021 at: https://www.countyhealthrankings.org/explore-health-rankings/measures-data-sources/county-health-rankings-model/health-factors/social-and-economic-factors/income/income-inequality
• 26 County Health Rankings and Roadmaps. Residential segregation - Black/White*. Accessed July 30, 2021 at: https://www.countyhealthrankings.org/explore-health-rankings/measures-data-sources/county-health-rankings-model/health-factors/social-and-economic-factors/family-social-support/residential-segregation-blackwhite
• 27 National Cancer Institute. Joinpoint trend analysis software. Accessed May 1, 2023 at: https://surveillance.cancer.gov/joinpoint/
• 28 Lüdecke D, Ben-Shachar MS, Patil I, Waggoner P, Makowski D. performance: an R package for assessment, comparison and testing of statistical models. J Open Source Softw 2021;6(60):
• 29 Bates D, Mächler M, Bolker B, Walker S. Fitting linear mixed-effects models using lme4. arXiv preprint arXiv:14065823. 2014
• 30 Fink DA, Kilday D, Cao Z. et al. Trends in maternal mortality and severe maternal morbidity during delivery-related hospitalizations in the United States, 2008 to 2021. JAMA Netw Open 2023; 6 (06) e2317641-e2317641
• 31 Hirai AH, Owens PL, Reid LD, Vladutiu CJ, Main EK. Trends in severe maternal morbidity in the US across the transition to ICD-10-CM/PCS from 2012-2019. JAMA Netw Open 2022; 5 (07) e2222966-e2222966
• 32 Dzakpasu S, Deb-Rinker P, Arbour L. et al; Canadian Perinatal Surveillance System (Public Health Agency of Canada). Severe maternal morbidity in Canada: temporal trends and regional variations, 2003-2016. J Obstet Gynaecol Can 2019; 41 (11) 1589-1598.e16
• 33 Arun J. AKI during pregnancy, pregnancy-related acute kidney injury, acute renal failure in pregnancy. Accessed September 18, 2023 at: https://www.cancertherapyadvisor.com/home/decision-support-in-medicine/critical-care-medicine/aki-during-pregnancy-pregnancy-related-acute-kidney-injury-acute-renal-failure-in-pregnancy/
• 34 Kendle AM, Salemi JL, Tanner JP, Louis JM. Delivery-associated sepsis: trends in prevalence and mortality. Am J Obstet Gynecol 2019; 220 (04) 391.e1-391.e16
• 35 Lisonkova S, Potts J, Muraca GM. et al. Maternal age and severe maternal morbidity: a population-based retrospective cohort study. PLoS Med 2017; 14 (05) e1002307
• 36 Kawakita T, Wilson K, Grantz KL, Landy HJ, Huang CC, Gomez-Lobo V. Adverse maternal and neonatal outcomes in adolescent pregnancy. J Pediatr Adolesc Gynecol 2016; 29 (02) 130-136
• 37 Ganchimeg T, Ota E, Morisaki N. et al; WHO Multicountry Survey on Maternal Newborn Health Research Network. Pregnancy and childbirth outcomes among adolescent mothers: a World Health Organization multicountry study. BJOG 2014; 121 (Suppl. 01) 40-48
• 38 Leppälahti S, Gissler M, Mentula M, Heikinheimo O. Is teenage pregnancy an obstetric risk in a welfare society? A population-based study in Finland, from 2006 to 2011. BMJ Open 2013; 3 (08) e003225
• 39 Vigil-De Gracia P, Olaya-Garay SX, Mata Hernández C. et al. Blood pressure changes in adolescents with preeclampsia: a multicentre, case-control study in Latin American hospitals. J Obstet Gynaecol Can 2021; 43 (01) 50-57
• 40 Amjad S, MacDonald I, Chambers T. et al. Social determinants of health and adverse maternal and birth outcomes in adolescent pregnancies: a systematic review and meta-analysis. Paediatr Perinat Epidemiol 2019; 33 (01) 88-99
• 41 Carr RC, McKinney DN, Cherry AL, Defranco EA. Maternal age-specific drivers of severe maternal morbidity. Am J Obstet Gynecol MFM 2022; 4 (02) 100529
• 42 Pordeus ACB, Katz L, Soares MC, Maia SB, Amorim MMR. Acute pulmonary edema in an obstetric intensive care unit: a case series study. Medicine (Baltimore) 2018; 97 (28) e11508
• 43 Poole JH, Spreen DT. Acute pulmonary edema in pregnancy. J Perinat Neonatal Nurs 2005; 19 (04) 316-331
• 44 Acharya A. Management of acute kidney injury in pregnancy for the obstetrician. Obstet Gynecol Clin North Am 2016; 43 (04) 747-765
• 45 Bime C, Poongkunran C, Borgstrom M. et al. Racial differences in mortality from severe acute respiratory failure in the United States, 2008-2012. Ann Am Thorac Soc 2016; 13 (12) 2184-2189
• 46 Garcia JG, Sznajder JI. Healthcare disparities in patients with acute respiratory distress syndrome. Toward equity. Am J Respir Crit Care Med 2013; 188 (06) 631-632
• 47 Cooke CR, Erickson SE, Eisner MD, Martin GS. Trends in the incidence of noncardiogenic acute respiratory failure: the role of race. Crit Care Med 2012; 40 (05) 1532-1538
• 48 Tangel VE, Matthews KC, Abramovitz SE, White RS. Racial and ethnic disparities in severe maternal morbidity and anesthetic techniques for obstetric deliveries: a multi-state analysis, 2007-2014. J Clin Anesth 2020; 65: 109821
• 49 Lange EMS, Toledo P. Peripartum racial/ethnic disparities. Int Anesthesiol Clin 2021; 59 (03) 1-7
• 50 Ehrenthal DB, Chichester ML, Cole OS, Jiang X. Maternal risk factors for peripartum transfusion. J Womens Health (Larchmt) 2012; 21 (07) 792-797
• 51 Hartenbach EM, Kuo HD, Greene MZ, Shrider EA, Antony KM, Ehrenthal DB. Peripartum blood transfusion among rural women in the United States. Obstet Gynecol 2020; 135 (03) 685-695