ObjectiveTo estimate the frequency of Positive Maternal Mental Health (PMMH) interpretation levels in pregnant women who attended prenatal consultation and to identify their association with obstetric and psychosocial factors.MethodsA cross-sectional study that included pregnant women who attended prenatal care at 12 or more weeks of gestation. The following scales were applied: Positive Mental Health Questionnaire (PMHQ), Goldberg Anxiety and Depression Scale, and Jong Gierveld Loneliness Scale.Results702 pregnant women were evaluated; 634 (90.3%) had flourishing PMMH, and 68 (9.7%) had non-flourishing PMMH. Among the latter, all were at an intermediate level, and none were languishing. Flourishing PMMH was more frequent in adults (91.2%) compared to adolescents (75.0%) and in women with higher education (93.0%) than in those with basic education (83.9%). The PMHQ factors and global score correlated positively with maternal age and negatively with anxiety, depression, emotional, social, and general loneliness. Associated with a higher frequency of non-flourishing PMMH were general loneliness OR:6.32[CI95%:3.38–11.82], social loneliness OR:5.98[CI95%:3.42–10.42], adolescence OR:3.47[CI95%:1.61–7.45], emotional loneliness OR:3.12[1.83–5.32], anxiety OR:2.14[CI95%:1.27–3.60], and depression OR:1.88[CI95%:1.09–3.25]. Less frequently: work occupation outside the home OR:0.41[CI95%:0.24–0.68], technical/technological studies OR:0.22[CI95%:0.08–0.60] and university OR:0.27[CI95%:0.10–0.71]. Preconception consultation, desired pregnancy, cesarean section, and fetal or neonatal death were not associated. In the adjusted model: general loneliness OR:3.02[CI95%:1.10–8.31], social loneliness OR:2.82[CI95%:1.38–5.79] and anxiety OR:1.93[CI95%:1.02–3.67], retained statistical significance.ConclusionNine out of ten pregnant women had flourishing PMMH, and none had languishing PMMH. None of the obstetric factors were associated with non-flourishing PMMH but with general loneliness, social loneliness, and anxiety.