Perturbations in the Biochemical Composition of Fetal Fluids Are Apparent in Surviving Bovine Somatic Cell Nuclear Transfer Pregnancies in the First Half of Gestation

Abstract Amniotic and allantoic fluid volumes and composition change dynamically throughout gestation. Cattle that are pregnant with somatic cell nuclear transfer (NT) fetuses show a high incidence of abnormal fluid accumulation (particularly hydrallantois) and fetal mortality from approximately midgestation. To investigate fetal fluid homeostasis in these pregnancies, Na, K, Cl, urea, creatinine, Ca, Mg, total PO4, glucose, fructose, lactate, total protein, and osmolalities were measured in amniotic and allantoic fluids collected at Days 50, 100, and 150 of gestation from NT pregnancies and those generated by the transfer of in vitro-produced embryos or by artificial insemination. Deviations in fetal fluid composition between NT and control pregnancies were apparent after placental and fetal organ development, even when no gross morphological abnormalities were observed. Individual NT fetuses were affected to varying degrees. Elevated allantoic Na was associated with lower K and increased allantoic fluid...