The association between antenatal depression symptom trajectories and preterm birth

Abstract

Antenatal depression has been associated with an increased risk of preterm birth (PTB). Whether improvement of depression mitigates the risk of PTB remains uncertain. Our objective was to evaluate whether, among pregnant people referred for mental health care, improvement in antenatal depression symptoms prior to delivery was associated with a reduction in PTB. This retrospective cohort study included all pregnant people referred to a perinatal collaborative care (CC) program for mental health care and who delivered between 2016-2021. Those referred to the CC program had access to subspecialty mental health treatment, including psychiatric consultation and psychotherapy. Depression symptoms were monitored via serial PHQ-9 screens every 2-4 weeks. Antenatal depression trajectories were determined by comparing the earliest prenatal PHQ-9 score after CC referral to the latest score before delivery. Trajectories were categorized as improved, stable, or worsened based on whether the PHQ-9 scores changed by at least one standard deviation (i.e., 5 points). Bivariable analyses were performed. A propensity score was generated using confounders that were significantly different on bivariable analyses across trajectories. This propensity score was included in multivariable models to control for imbalance across the exposure. Of the 732 pregnant people included, antenatal depression symptoms improved in 256 (35.0%), remained stable in 437 (59.7%), and worsened in 39 (5.3%) (Table 1). The incidence of preterm birth was 12.5%, 14.0%, and 30.8% in those whose depression symptoms improved, remained stable, or worsened, respectively (p=0.009, Table 2). Compared to those who remained stable or worsened, those who had an improved antenatal depression symptom trajectory had a significantly decreased odds of PTB (aOR 0.60, 95% CI 0.39-0.94). For pregnant people with mental health conditions, having an improved antenatal depression symptom trajectory is associated with decreased odds of PTB. These data can be used to inform counseling regarding management of depression during pregnancy.View Large Image Figure ViewerDownload Hi-res image Download (PPT)