Serum α-fetoprotein concentration in extremely low-birthweight infants

Extremely low-birthweight infants (ELBWI) are at greater risk of developing hepatoblastoma than are normal-weight infants. Serum α-fetoprotein (AFP) plays an important role as a tumor marker in the diagnosis of hepatoblastoma, therefore the aim of this study was to determine the changes in serum AFP concentration after birth in ELBWI.

Data were obtained for infants born between January 2005 and March 2008 with birthweight <1000 g who were followed up at Gunma Children's Medical Center with clinical examinations, including monitoring of the development of hepatoblastoma. The relationship between serum AFP concentration and age was analyzed up to 730 days after birth.

Overall, 95 serum AFP measurements were obtained from 23 infants 30-730 days of age, with gestational age 24-32 weeks, and birthweight 498-982 g. Log₁₀ (AFP [ng/mL]) was significantly correlated with log₁₀ (age [days]) (r = -0.961, P = 0.000, n = 95), with the following regression formula: log₁₀ (AFP [ng/mL]) = 11.063 - 3.752 log₁₀ (age [days]) (adjusted R²  = 0.923, n = 95). The standard error of the estimate, mean log₁₀ (age [days]), and the sum of squares for log₁₀ (age [days]) were 0.363, 2.503, and 10.579, respectively.

A correlation was found between serum AFP concentration and age in ELBWI, and the 95%CI of serum AFP concentration was determined for ELBWI up to 2 years after birth.