Association between stillbirth ≥23 weeks gestation and acute psychiatric illness within 1 year of delivery

Background: Stillbirth has been associated with emotional and psychologic symptoms. The association between stillbirth and diagnosed postpartum psychiatric illness is less well-known. Objective: The purpose of this study was to determine whether women have a higher risk of experiencing clinician-diagnosed psychiatric morbidity in the year after stillbirth vs livebirth. Study Design: This retrospective cohort study used International Classification of Diseases, 9th Revision, Clinical Modification diagnosis and procedure codes to identify participants, exposures, and outcomes within the Florida State Inpatient and State Emergency Department databases. The first delivery of female Florida residents aged 13–54 years old from 2005–2014 was included; women with International Classification of Diseases, 9th Revision, Clinical Modification coding for psychiatric illness or substance use during pregnancy were excluded. The exposure was an International Classification of Diseases, 9th Revision, Clinical Modification diagnosis code during delivery hospitalization of a stillbirth at ≥23 weeks gestation. The primary outcome was a primary or secondary International Classification of Diseases, 9th Revision, Clinical Modification diagnosis code during an Emergency Department encounter or inpatient admission within 1 year of delivery for a composite of psychiatric morbidity: suicide attempt, depression, anxiety, posttraumatic stress disorder, psychosis, acute stress reaction, or adjustment disorder. The secondary outcome was a substance use composite of drug or alcohol use or dependence. We compared outcomes after delivery of stillbirth vs livebirth using multivariable logistic regression, adjusting for maternal sociodemographic factors, medical comorbidities, and severe intrapartum morbidity. We also used Cox proportional hazard models and tested for violation of the proportional hazard assumption to identify the highest risk time within the year after stillbirth delivery for the primary outcome, adjusting for the same factors and morbidities as in the logistic regression model. Results: A total of 8292 women with stillborn singletons and 1,194,758 with liveborn singletons were included. Within 1 year of hospital discharge after stillbirth, 4.0% of the women (n=331) had an Emergency Department encounter or inpatient admission that was coded for psychiatric morbidity; the risk was nearly 2.5 times higher compared with livebirth (1.6%; n=19,746); adjusted odds ratio, 2.47; 95% confidence interval, 2.20– 2.77). Women also had higher risk of having an Emergency Department encounter or inpatient admission coded for drug or alcohol use or dependence in the year after delivery of stillbirth vs livebirth (124 [1.5%] vs 7033 [0.6%]; adjusted odds ratio, 2.41; 95% confidence interval, 1.99–2.90). Cox proportional hazard modeling suggested that the highest risk interval for postpartum psychiatric illness was within 4 months of stillbirth delivery (adjusted hazard ratio, 3.26; 95% confidence interval, 2.63–4.04), although the risk remained high during the 4–12 months after delivery (adjusted hazard ratio, 2.42; 95% confidence interval, 2.13–2.76). Conclusion: Coding for psychiatric illness or substance misuse in Emergency Department visits or hospital admissions in the year after delivery of livebirths was not uncommon, corresponding to nearly 2 per 100 women. However, having a stillbirth was associated with increased risk of both psychiatric morbidity (corresponding to 1 per 25 women) and substance misuse (corresponding to 3 in 100 women), with the highest risk of postpartum psychiatric morbidity occurring from delivery until 4 months after delivery.