Population-Based Study of Risk Factors for Severe Maternal Morbidity
Article first published online: 15 OCT 2012
© 2012 Blackwell Publishing Ltd
Paediatric and Perinatal Epidemiology
Volume 26, Issue 6, pages 506–514, November 2012
How to Cite
Gray, K. E., Wallace, E. R., Nelson, K. R., Reed, S. D. and Schiff, M. A. (2012), Population-Based Study of Risk Factors for Severe Maternal Morbidity. Paediatric and Perinatal Epidemiology, 26: 506–514. doi: 10.1111/ppe.12011
- Issue published online: 15 OCT 2012
- Article first published online: 15 OCT 2012
- severe maternal morbidity;
- pregnancy complications;
Background: Severe maternal morbidity (SMM) is a serious health condition potentially resulting in death without immediate medical attention, including organ failure, obstetric shock and eclampsia. SMM affects 20 000 US women every year; however, few population-based studies have examined SMM risk factors.
Methods: We conducted a population-based case–control study linking birth certificate and hospital discharge data from Washington State (1987–2008), identifying 9485 women with an antepartum, intrapartum or postpartum SMM with ≥3-day hospitalisation or transfer from another facility and 41 112 random controls. Maternal age, race, smoking during pregnancy, parity, pre-existing medical condition, multiple birth, prior caesarean delivery, and body mass index were assessed as risk factors with logistic regression to estimate odds ratios (OR) and 95% confidence intervals [CI], adjusted for education and delivery payer source.
Results: Older women (35–39: OR 1.65 [CI 1.52, 1.79]; 40+: OR 2.48 [CI 2.16, 2.81]), non-White women (Black: OR 1.82 [CI 1.64, 2.01]; American Indian: OR 1.52 [CI 1.32, 1.73]; Asian/Pacific Islander: OR 1.30 [CI 1.19, 1.41]; Hispanic: OR 1.17 [CI 1.07, 1.27]) and women at parity extremes (nulliparous: OR 1.83 [CI 1.72, 1.95]; parity 3+: OR 1.34 [CI 1.23, 1.45]) were at greater risk of SMM. Women with a pre-existing medical condition (OR 2.10 [CI 1.88, 2.33]), a multiple birth (OR 2.54 [CI 2.26, 2.82]) and a prior caesarean delivery (OR 2.08 [CI 1.93, 2.23]) were also at increased risk.
Conclusion: The risk factors identified are not modifiable at the individual level; therefore, provider and system-level factors may be the most appropriate target for preventing SMM.