FAILURE TO DETECT INTRAUTERINE GROWTH RESTRICTION FOLLOWING IN-UTERO EXPOSURE TO MRI

Echo planar imaging is a form of MRI with short image acquisition time s, which permits in utero fetal imaging without motion artefacts. Echo planar imaging has been used to measure accurately fetal organ volume and to assess placental function. Two small animal studies have sugge sted the possibility of intrauterine growth restriction consequent upo n MRI. We thus performed a prospective study of pregnancies in which f etuses were exposed to echo planar imaging, compared with a control gr oup in which there was no in utero echo planar imaging exposure. There were no significant differences between the groups when maternal age, parity, proportion of smokers and proportion of Caucasian women were compared. Although the gestational age of delivery was lower in the ec ho planar imaging group, the proportion of women delivering prematurel y was not significantly different. Although infant birthweights were s ignificantly lower in the MRI group, the corrected birthweight for ges tational age centiles (individualized birthweight ratio) was not signi ficantly different between the two groups. In utero exposure to echo p lanar imaging thus did not have a marked effect on intrauterine fetal growth. A 10 year follow-up study of all infants imaged in utero is be ing performed.