Theorems, proofs, laws and rules are commonly named according to the presumed discoverer, but often earlier investigators have contributed substantially to the findings. One example of this is Hellin’s law, which was named after Hellin, although he was not the first to derive it. In research on twinning and higher multiple maternities, the law has played a central role because it is approximately correct, despite showing discrepancies that are difficult to explain or eliminate. However, most studies are based on empirical rates of multiple maternities. Such studies can only serve to identify errors too large to be characterized as random. It has been mathematically proven that Hellin’s law does not hold as a general rule. Consequently, improvements to this law have been proposed.
Part of the book: Multiple Pregnancy