Postnatal depressive symptoms and associated factors among parents of newborns: a cross-sectional study in tropical Sanya, China

Objective To determine the prevalence of postnatal depressive symptoms and associated factors among parents of newborns in Sanya, a tropical city in China.Design A hospital-based cross-sectional survey with prospective data collection.Setting Shanghai Children's Medical Center, Hainan Branch, Sanya, China, between February and March 2025.Participants 263 parents of newborns aged 0-4 weeks (134 fathers, 129 mothers) recruited by consecutive sampling. Each parent consented individually, with data treated independently.Measurements and findings Exposures were parental gender, perceived social support, life satisfaction, quality of life, and sociodemographic factors. The outcome was elevated depressive symptoms, defined as an Edinburgh Postnatal Depression Scale score of 13 or more. Participants self-completed the Multidimensional Scale of Perceived Social Support (MSPSS), Satisfaction with Life Scale (SWLS), and WHO Quality of Life-BREF (WHOQOL-BREF) through a secure online platform. Overall, 58 of 263 parents (22.1%) had elevated postnatal depressive symptoms, a higher prevalence than the global average. After adjustment, mothers had higher odds than fathers (adjusted odds ratio [aOR] = 3.14, 95% confidence interval [CI]: 1.41-6.97), and each one-point increase in the WHOQOL-BREF psychological domain score was associated with a 61% reduction in the odds of elevated symptoms (aOR = 0.39, 95% CI: 0.15-0.99).Conclusions Postnatal depressive symptoms are common among parents in this tropical, ethnically diverse setting, with maternal vulnerability particularly pronounced.Implications for practice The findings support routine screening of both mothers and fathers, targeted outreach for migrant and low-income families, and integration of resilience-building into perinatal care in tropical settings.