Second trimester amniotic fluid transferrin and uric acid predict infant birth outcomes

Abstract

Objective: To establish whether second trimester amniotic fluid protein and/or uric acid concentrations were associated with and predictive of infant birth weight and/or gestational age.

Methods: Second trimester amniotic fluid samples (n = 230) in mothers undergoing age-related amniocentesis for genetic testing were collected and quantified using capillary zone electrophoresis (CZE) for albumin, IgG, transferrin and uric acid. Maternal characteristics (prepregnancy weight and height, parity, ethnicity, smoking status) and infant birth weight, gestational age and gender were obtained from questionnaires and maternal obstetrical chart review.

Results: Preterm infants had higher concentrations of second trimester amniotic fluid transferrin than term infants (P = 0.0215). Transferrin was negatively associated with length of gestation, whereas uric acid was positively associated with the gestational age in spontaneous vaginal delivery (SVD) infants. Uric acid was also a significant predictor of the infant birth weight in grams.

Conclusion: Second trimester amniotic fluid transferrin and uric acid concentrations are related to subsequent birth outcomes and might emerge as biomarkers of early fetal development.