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Updated: Aug 17, 2026

Quantitating Iron Transport Across the Mouse Placenta In Vivo Using Nonradioactive Iron Isotopes
Published on: May 10, 2022
Non protein bound iron concentrations in amniotic fluid
D Gazzolo1, S Perrone, P Paffetti
1Department Paediatrics G. Gaslini, Children's University Hospital, 16148 Genoa, Italy.
Objectives:
To investigate whether amniotic fluid concentrations of non protein bound iron (NPBI) vary with growth in healthy fetuses and also offer a reference curve in the second trimester of pregnancy.
Design And Methods:
Amniotic fluid concentrations of NPBI were measured by HPLC in 118 women with physiological singleton pregnancies, who underwent amniocentesis for fetal karyotype between weeks 15 and 18 of gestation.
Results:
NPBI increased progressively from weeks 14--15 to weeks 15--16, peaking at 17--18 weeks of gestation. NPBI values regressed positively with gestational age (GA). Multiple linear regression analysis between NPBI, as dependent variable, and various fetal parameters, as independent variables, showed a statistically significant regression coefficient with GA, bi-parietal diameter and transverse cerebellar diameter.
Conclusions:
The present data constitutes the first quantification of NPBI concentrations in amniotic fluid under physiological conditions. Correlations with GA and ultrasound fetal biometry suggest that NPBI may play a role in fetal growth.
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