The association between preterm birth and postpartum mental healthcare utilization among California birthing people.

BACKGROUND: While mental health conditions such as postpartum depression are common, little is known about how mental healthcare utilization varies after term versus preterm delivery. OBJECTIVE: This study aimed to determine whether preterm birth is associated with postpartum inpatient and emergency mental healthcare utilization. STUDY DESIGN: The study sample was obtained from a database of live-born neonates delivered in California between the years of 2011 and 2017. The sample included all people giving birth to singleton infants between the gestational age of 20 and 44 weeks. Preterm birth was defined as <37 weeks' gestation. Emergency department visits and hospitalizations with a mental health diagnosis within 1 year after birth were identified using International Classification of Diseases codes. Logistic regression was used to compare relative risks of healthcare utilization among people giving birth to preterm infants vs term infants, adjusting for the following covariates: age, race or ethnicity, parity, previous preterm birth, body mass index, tobacco use, alcohol or drug use, hypertension, diabetes mellitus, adequacy of prenatal care, education, insurance payer, and the presence of a mental health diagnosis before birth. Results were then stratified by mental health diagnosis before birth to determine whether associations varied based on mental health history. RESULTS: Of our sample of 3,067,069 births, 6.7% were preterm. In fully adjusted models, compared with people giving birth to term infants, people giving birth to preterm infants had a 1.5 times (relative risk; 95% confidence interval, 1.4-1.7) and 1.3 times (relative risk; 95% confidence interval, 1.2-1.4) increased risk of being hospitalized with a mental health diagnosis within 3 months and 1 year after delivery, respectively. People giving birth to preterm infants also had 1.4 times (95% confidence interval, 1.3-1.5) and 1.3 times (95% confidence interval, 1.2-1.4) increased risk of visiting the emergency department for a mental health diagnosis within 3 months and 1 year after birth, respectively. Stratifying by preexisting mental health diagnosis, preterm birth was associated with an elevated risk of mental healthcare utilization for people with and without a previous mental health diagnosis. CONCLUSION: We found that preterm birth is an independent risk factor for postpartum mental healthcare utilization. Our findings suggest that screening for and providing mental health resources to birthing people after delivery are crucial, particularly among people giving birth to preterm infants, regardless of mental health history.