OBJECTIVE:To estimate whether stillbirth at 23 weeks of gestation or more is associated with increased risk of severe maternal morbidity compared with live birth, when stratified by maternal comorbidities.METHODS:This retrospective cohort study used International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) diagnosis and procedure codes within the Healthcare Cost and Utilization Project's Florida State Inpatient Database. The first delivery of female Florida residents aged 13-54 years old from 2005 to 2014 was included. The exposure was an ICD-9-CM code of stillbirth at 23 weeks of gestation or more; the control was an ICD-9-CM code of singleton live birth. Deliveries were stratified by the presence of 1 or more conditions within a well-validated maternal morbidity composite using ICD-9-CM codes during delivery hospitalization. The primary outcome was an ICD-9-CM diagnosis or procedure code during delivery hospitalization of any indices within the Centers for Disease Control and Prevention's severe maternal morbidity composite. Multivariable analyses adjusted for maternal sociodemographic factors and delivery mode to compare outcomes after stillbirth with live-birth delivery.RESULTS:Nine thousand five hundred twenty-three women who delivered stillborn fetuses and 1,353,044 with liveborn neonates were included. Among 6,590 stillbirths and 935,913 live births without maternal comorbidities, severe maternal morbidity was significantly more common during stillbirth delivery (n=345 [5.2%]), corresponding to a seven-fold increased risk compared with live birth (n=8,318 [0.9]; adjusted odds ratio [aOR] 7.05 [95% CI 6.27-7.93]). Among 2,933 stillbirths and 417,131 live births with maternal comorbidities, severe maternal morbidity was significantly more common during stillbirth delivery (n=390 [13.3%]): the risk was more than six-fold higher comparatively (n=11,122 [2.7%]; aOR 6.21 [95% CI 5.54-6.96]). Most maternal comorbidities were individually associated with higher risk of severe maternal morbidity during stillbirth compared with live-birth delivery.CONCLUSION:Though severe maternal morbidity is overall uncommon, delivering a stillborn fetus 23 weeks of gestation or greater is associated with increased likelihood of severe maternal morbidity, particularly among women with comorbidities, suggesting health care providers must be vigilant about severe maternal morbidity during stillbirth delivery.