Association between history of pregnancy loss and preterm birth: the mediating role of maternal anxiety.

BACKGROUND: A history of pregnancy loss may elevate maternal anxiety in subsequent pregnancies. Both prior pregnancy loss and maternal anxiety are associated with an increased risk of preterm birth. However, the role of maternal anxiety in the association between a history of pregnancy loss and preterm birth remains unclear. In this study, we aim to investigate the association among history of pregnancy loss, maternal anxiety, and preterm birth and to explore the potential mediating effect of maternal anxiety on this relationship. METHODS: This retrospective cohort study included 109 preterm and 558 term births between January 2021 and October 2023. We collected data on maternal history of pregnancy loss and pregnancy outcomes from electronic medical records. Maternal anxiety was assessed using the Self-Rating Anxiety Scale in the mid-trimester. Mediation analyses were used to determine whether maternal anxiety mediated the association between a history of pregnancy loss and preterm birth. RESULTS: Compared with women who had full-term delivery, those who had preterm delivery were more likely to have a history of pregnancy loss (p < 0.001) and exhibited higher anxiety levels during pregnancy (p = 0.002). A history of pregnancy loss had a significant impact on the occurrence of preterm birth in subsequent pregnancies. This effect was mediated by maternal anxiety during pregnancy after adjusting for age, employment status, mode of conception, and pregnancy complications (p = 0.030). The mediated proportion was 10.9% (95% CI 0.9, 44.0). CONCLUSION: A history of pregnancy loss, prenatal anxiety, and preterm birth are interconnected. Prenatal anxiety takes a potential role in mediating the relationship between a history of pregnancy loss and the risk of preterm birth. Women with a history of pregnancy loss are advised to receive antenatal mental health interventions during subsequent pregnancies to prevent preterm births.