The deterioration of mental health in the general population has been one of the main consequences of the COVID-19 health crisis, with differences in diverse groups. Specifically, recent studies report an increased risk for the development of symptoms of anxiety and depression during the perinatal period, as well as a negative impact on the newborn. Objective: The objective of this study was to examine the differences in mental health, infant and obstetric variables, and childbirth experience in the public and private health systems in Chilean primiparous women before and during the COVID-19 pandemic. Subjects and Method: This quantitative study compared two cohorts. The first one included mothers with babies born before the COVID-19 pandemic (N = 81) and the second one involved mothers who delivered during the pandemic (N = 71). Sociodemographic and obstetric history, depression, anxiety, and stress were evaluated in both groups using self-report questionnaires (EPDS, DASS-21). Differences between groups were assessed with ANCOVA, t-tests, and chi-square tests. Results: Women who delivered during the pandemic reported greater depressive symptoms and their babies were smaller and had less weeks of gestation than babies born before the COVID-19 pandemic. However, this group maintained exclusive breastfeeding for a longer period. There were no differences in the experience of childbirth between the groups, but there were differences in relation to the public or private nature of the hospital where the mothers were seen. Conclusions: The pandemic negatively affected the mental health of mothers, posing significant challenges to promoting the emotional well-being of mothers and their infants.Una de las principales consecuencias de la crisis sanitaria por COVID-19 ha sido el deterioro de la salud mental de la población, con variaciones en distintos grupos. En este escenario, la evidencia reporta un mayor riesgo de sintomatología ansiosa y depresiva durante el período perinatal, así como un impacto negativo en el recién nacido. Objetivo: Examinar las diferencias en la salud mental, variables obstétricas y del recién nacido. y experiencia de parto en los sistemas de salud público y privado, en mujeres primíparas chilenas, pre-pandemia y durante la pandemia. Sujetos y Método: Estudio cuantitativo comparando 2 cohortes. La primera incluyó madres con bebés nacidos antes de la pandemia por COVID-19 (N=81) y la segunda, madres con partos durante la pandemia (N = 71). Se evaluaron en ambos grupos antecedentes sociodemográficos y obstétricos, depresión, ansiedad y estrés a partir de cuestionarios de autorreporte. Las diferencias entre grupos fueron evaluadas con ANCOVA, pruebas t y prueba de chi cuadrado. Resultados: Las mujeres con partos durante la pandemia reportaron mayor sintomatología depresiva y sus bebés presentaron menor edad gestacional y, levemente, menor talla que los bebés nacidos antes del COVID-19. Sin embargo, este grupo mantuvo la lactancia exclusiva por más tiempo. No se observaron diferencias en la experiencia de parto entre los grupos, pero sí en relación con el carácter público o privado del hospital donde se atendieron las madres. Conclusiones: La pandemia afectó negativamente la salud mental de las madres, lo que plantea desafíos importantes para la promoción del bienestar emocional de las madres y sus bebés.