Pregnancy in adolescence represents a major nutritional challenge, with competing demands between maternal development and fetal growth. Choline is the essential nutrient with a critical role for fetal brain development and exhibits distinct metabolic patterns in pregnant adolescents aged 15–19 years compared to adult pregnant women. This narrative review examines the specific impact of choline status on fetal neurodevelopment in adolescent pregnancies. A comprehensive literature review was conducted using PubMed and Web of Science databases from 2000 to 2025, focusing on choline metabolism, placental transport mechanisms, and neurodevelopmental outcomes in adolescent pregnancy. Adolescent pregnant women demonstrate reduced choline clearance (0.8 ± 0.2 vs. 1.2 ± 0.3 mL/min/kg), decreased choline kinase activity (25–30% reduction), and reduced placental transporter expression (CTL1 reduced by 15–20%) compared to adults. These metabolic differences result in maternal–fetal competition for limited choline resources, potentially compromising fetal brain development during critical neurodevelopmental windows. The consequences include increased risk of neural tube defects, altered hippocampal development, and long-term cognitive impairments in offspring. Adolescent pregnancy creates a unique biochemical environment that may predispose to choline deficiency with lasting neurodevelopmental consequences, and current supplementation guidelines do not address adolescent-specific needs, pointing out the urgent requirement for appropriate age recommendations and targeted interventions to optimize maternal and fetal outcomes in this vulnerable population.