Background <p>Depression during pregnancy has been associated with adverse birth outcomes globally. However, no case-control study has explored the relationship in Uttar Pradesh, India. To fulfil this gap, this study investigates the association of maternal psychological factors with adverse birth outcomes, specifically low birth weight and/or preterm birth.</p> Methods <p>This case-control study was conducted between October 2024 and January 2025 in the Raebareli district of Uttar Pradesh. The study included 425 postpartum women (within 3 months of delivery). Cases (212) were women who delivered LBW infants (&lt; 2500&#xa0;g) and/or preterm (&lt; 37 weeks). Controls (213) had term deliveries (≥ 37 weeks) with normal birth weight (≥ 2500&#xa0;g).</p> Results <p>After adjusting for potential confounders, maternal depressive symptoms were significantly associated with increased odds of preterm birth and LBW [AOR = 3.43]. Similarly, anxiety symptoms were also significantly associated with these adverse outcomes [OR = 1.89]. Additionally, sleep disturbances were linked to a twofold increase of adverse outcomes [OR = 2.13]. Other psychological factors, such as persistent crying or weeping due to prolonged unhappiness, a tendency to unnecessarily blame oneself for negative events, and thoughts of self-harm during pregnancy were also found to be significantly associated with an increased odds of preterm birth and LBW.</p> Conclusion <p>This study reveals a strong association between maternal psychological factors and adverse pregnancy outcomes, including low birth weight and preterm birth, in Central Uttar Pradesh. The findings highlight the urgent need to integrate mental health screening and support into routine antenatal care to improve maternal and neonatal outcomes.</p>