Related Experiment Video
Updated: Jul 28, 2026
Instrumentation of Near-term Fetal Sheep for Multivariate Chronic Non-anesthetized Recordings
Published on: October 25, 2015
Chronic fetal hypoxia increases activin A concentrations in the late-pregnant sheep
V G Supramaniam1, G Jenkin, J Loose
1Department of Physiology, Monash University, Clayton, Victoria, Australia.
Objective:
To determine whether activin A concentrations are altered in chronic fetal hypoxemia and intrauterine fetal growth restriction (IUGR).
Design:
In vivo animal experimental model.
Setting:
Department of Physiology, Monash University.
Population:
Chronically catherised fetal sheep in late pregnancy.
Methods:
Chronic fetal hypoxia and IUGR were experimentally induced by single umbilical artery ligation (SUAL) in catheterised fetal sheep. Maternal and fetal blood samples and amniotic fluid (AF) samples were collected during surgery and thereafter on alternate days, until the time of delivery for analyte measurement. Fetal blood gas parameters were measured daily.
Main Outcome Measures:
Plasma and AF was used to analyse activin A, prostaglandin E2 (PGE2) and cortisol and fetal blood gas analysis was undertaken in whole blood.
Results:
SUAL produced asymmetric IUGR and non-acidaemic chronic fetal hypoxia and resulted in preterm labour (129 [3] days). AF activin A concentrations were 10-fold higher in the SUAL group than in controls whereas levels in the fetal and maternal circulations were similar between groups.
Conclusions:
SUAL-induced IUGR and fetal hypoxaemia increases AF activin A. This may be an important adaptive or protective response to IUGR.
