alpha-Fetoprotein levels in fullterm and very low birthweight infants

Plasma alpha-fetoprotein (alpha-FP) levels were determined in fullterm and very low birthweight (VLBW) infants in the first week of life and serially in a cohort of VLBW infants for the first 24 weeks after delivery. A rapid decline in alpha-FP levels was observed in both the fullterm and VLBW infants initially. Beyond 2 weeks of age, there was a gradual, linear decline until 6 weeks, followed by a more rapid period of decline from 6 to 16 weeks. The decline in the ensuing weeks demonstrated an asymptotic pattern. The half-life of alpha-FP was 7.5 days in the first week of life in both fullterm and preterm infants, 28.7 days from 2 to 6 weeks of life and 11.9 days from 6 to 16 weeks of life in VLBW infants.