The role of preimplantation sonographic exposure in postimplantation development and pregnancy outcome.
To determine what, if any, effects exposure to ultrasonic beams has on preimplantation embryos we isolated mouse blastocysts and assessed resorption rate, pregnancy rate, decidual swelling volume, and live birth rate after in vitro exposure with subsequent transfer to surrogate mothers. The blastocyst stage embryos were isolated by flushing the uteri of pregnant animals with a phosphate buffered medium. Blastocysts at a discrete stage of development were pooled and transferred to a PB1-methylcellulose medium. This medium is specifically designed to maintain the embryos in a high viscosity solution during the sonographic exposure to prevent microcavitation. After the exposure, the embryos were washed free of methylcellulose and transferred to the uteri of pseudopregnant surrogate mothers. A total of 660 blastocyst stage embryos were distributed among seven treatment groups. After exposure, the embryos were transferred to 54 surrogate mothers. A total of 199 embryos were implanted successfully for postimplantation evaluation. An additional 427 blastocysts were distributed among four treatment groups and transferred to 46 surrogate mothers to assess the effect of sonographic exposure on birth rate. The results indicate possible deleterious effects (decreased implantation rate, increased resorption rate, decreased decidual swelling volume, and increased stillbirth rate) of short ultrasonic exposures (1 min and 5 min) on mouse blastocyst function.
Iannaccone
P M
PM
Department of Pathology, Northwestern University, Chicago, IL.
Van Gorder
M
M
Madsen
E L
EL
Martin
A O
AO
Garton
R
R
D000818:Animals; D001755:Blastocyst / Q000000981:diagnostic imaging*; D004624:Embryo Transfer; D047108:Embryonic Development / Q000502:physiology; D005260:Female; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008813:Mice, Inbred ICR; D011247:Pregnancy; D011256:Pregnancy Outcome; D016216:Ultrasonography, Prenatal / Q000009:adverse effects* / Q000379:methods