BACKGROUND:
In Chile, seven out of ten infant deaths occur within the first year of life, highlighting the preventive value of initial prenatal care. Since 2007, the national program Chile Crece Contigo (ChCC)—which reaches about 67% of pregnant women—has incorporated psychosocial assessment at the first antenatal visit, aiming to detect social and economic vulnerabilities.

OBJECTIVES:
To estimate the association between psychosocial risks and poverty—identified at the first prenatal visit—and under-five mortality (<60 months) in the national ChCC cohort (2007-2023).

METHODS:
A retrospective cohort linked ChCC-pregnancy files (2007-2023) with national death certificates. Outcome: time (days) from birth to death; Exposures: psychosocial risks, such as, low maternal education ≤6 years, adolescent (<19 years), late antenatal care (≥20 weeks), substance abuse, depressive symptoms, low social support, gender-based violence, and low income. Survival analysis used Kaplan–Meier and log-rank test (p<0.05) Cox regression was applied to estimate adjusted Hazard Ratio (aHR) with 95% CI (Stata v.19).

RESULTS:
The cohort comprised 2,419,752 mother–child dyads, 2.25 million person-years and 21,619 under-five deaths, of which 86% occurred in the first-year. The survival curves diverge as early as the first week (p<0.05). The hazard ratio tripled with low maternal education (aHR=3.54;95%CI:3.30–3.80) The hazard ratio tripled with adolescent pregnancy (aHR=3.24 to 3.12, (p<0.001)); it doubled with late antenatal care (aHR=2.83 to 2.14, (p<0.001)); and increased with substance use (aHR=1.38;95%CI:1.29–1.48), low social support (aHR=1.46;95%CI:1.36–1.56), and gender-based violence (aHR=1.35; 95%CI:1.24–1.47). The hazard ratio decreased in association with low income (aHR=0.60; 95%CI:0.54–0.67).

CONCLUSIONS:
Psychosocial factors, when identified early and addressed through appropriate public policies, can significantly reduce infant mortality. Midwives play a fundamental role in this process, acting as key agents in the detection, referral, and follow-up of psychosocial risks during pregnancy

KEY MESSAGE:
A swift psychosocial check at booking lets midwives turn every consultation into a life-saving equity intervention. Education faculty development 1