Los primeros mil días, desde la concepción hasta los dos años de edad, es una etapa crítica para el desarrollo y prevención de la mala nutrición en todas sus formas, y una ventana de oportunidad para la implementación de intervenciones que aseguren el óptimo desarrollo y mejoren el capital humano. Este artículo especial tiene como objetivo presentar los principales retos para la atención a la salud y nutrición en los primeros mil días, los avances en el desarrollo e implementación de una estrategia para tal fin y formular recomendaciones de política pública prioritarias para la próxima administración.

In emergencies, the maternal and child populations face increased risk of morbidity and mortality, often exacerbated by malnutrition. Breastfeeding, adequate complementary feeding, and appropriate prenatal care can mitigate these risks. This descriptive cross-sectional study compared data collected before and after Hurricane John related to maternal, infant and young child feeding (IYCF) practices and the nutritional status of pregnant women and children under two years of age. Data were collected in December 2024 from the two provinces most affected in Guerrero, Mexico. Surveys were completed for 239 children through caregivers and 76 pregnant women, alongside anthropometric assessments. After the disaster, findings showed a significant decline in breastfeeding among 0–6-month-olds (88.7% to 71.1%) and an increase in dietary diversity in complementary feeding (3.6 ± 2.1 vs. 4.5 ± 1.5 food groups). Malnutrition, based on weight-for-length z-scores, was observed in 4.8% of children aged 0–6 months and 2.6% of those aged 6–24 months. According to mid-upper arm circumference, 8.4% of children aged 0–6 months presented malnutrition. Among pregnant women, based on body mass index, 41.5% had excessive pre-pregnancy weight, while 12.3% were underweight. These findings underscore the urgent need to integrate maternal and child nutrition into emergency preparedness and response strategies to protect vulnerable populations in Mexico.