Response to JAMA Pediatrics paper on the association of prenatal ultrasonography and autism spectrum disorder by the ISUOG Safety Committee, published 12 Feb 2018
Dr Christoph Lees' comment on the JAMA Pediatrics paper:
“This modest sized retrospective study purports to show a relationship between prenatal ultrasound and autism. Women should be reassured that it shows no link at all between duration of ultrasound exposure and autism, nor between ultrasound energy used and autism.
One problem with the study design is that the authors don't tell us 'up front' what the key comparisons they are looking for are. The authors choose many comparisons including an invented and previously unknown index: time weighted mean depth of ultrasound. They don't describe this time-weighted mean depth of ultrasound index - as a group of clinicians and scientists closely involved in all aspects of ultrasound safety we have no idea what they are describing. In short, this ultrasound index has no obvious scientific or biological justification.
Further, the authors have not corrected for their many comparisons: you don't have to be a statistician to know that if you toss a coin enough times you're bound to get a result you are looking for.
In summary, autism and prenatal ultrasound are both really contentious areas that easily lead to unwarranted alarm for women and false messages. This study, if read carefully is in fact very reassuring in showing no apparent link between pregnancy ultrasound and risk of autism. It's a shame that the paper as it is presented is open to some misinterpretation which we feel sure neither the authors nor journal would have wanted to see.”
Perinatal Doppler and Vascular Focus Group (Chair), Safety Committee, Simulation Task Force, Scientific Committee
Christoph Lees is a Maternal-Fetal Medicine subspecialist, Consultant Obstetrician and Head of Fetal Medicine at Imperial College London where he is Clinical Reader. He is visiting Professor, KU Leuven, Belgium, was RCOG inaugural National Ultrasound Officer 2010-2013 and Vice Chairman, RCOG Subspecialty Committee 2011-2013. His research focuses on pre-eclampsia, cardiovascular adaptation, Doppler, intra-uterine growth restriction and non-invasive fetal surgery.
Specialties: Fetal anomaly screening T2; fetal biometry and wellbeing; aneuploidies; fetal anomalies; fetal growth restriction; maternal and fetal Doppler; preeclampsia; safety of ultrasound