The long arms of anencephaly: A refutation.

A paper published in 1925 reported that human fetuses with anencephaly have arms that are longer than normal. This finding was accepted as true through the early 1990s. An analysis of body dimensions done in 1996 and enlarged and updated here shows that the arms of human fetuses with anencephaly are appropriate for gestational age and normal in proportion to their leg lengths. A subtle difference in measurement technique was found to explain the discordant findings.