K. Harding et al., A STUDY OF THE BIOEFFECTS OF MULTIPLE PRENATAL ULTRASOUND SCANS IN FETAL SHEEP, Journal of maternal-fetal investigation, 6(2), 1996, pp. 77-82
Objective: Multiple prenatal ultrasound scans in macaque monkeys have
been shown to reduce newborn neutrophil and monocyte counts and to low
er birth weight. The purpose of this study was to investigate if simil
ar effects could also occur in a sheep model. Methods: Thirty pregnant
Merino ewes were allocated at random to a protocol of multiple ultras
ound scans involving a total of 440 min of insonation or to sham proce
dures. Each fetus was delivered by caesarean section at 141 days gesta
tion (term = 150 days). Results: There were no differences between the
exposed and control groups in umbilical venous hematological paramete
rs; mean birth weights; weights of the major organs; lengths of bones;
markers of bone, liver, and thyroid metabolism; or bone mineral conte
nt. Conclusions: The effects on hematological parameters and growth ob
served after multiple prenatal ultrasound examinations in monkeys were
not shown to occur in a fetal sheep model.