Why are boys more likely to be preterm than girls? Plus other related conundrums in human reproduction.

The present note offers two quite different points of interest. The first concerns the cause(s) of preterm labour. This is an important practical problem because of the associated morbidity and mortality. The second point of interest is theoretical. Some logically inter-related empirical propositions are formulated: none has been established but evidence for each is apparently evidence for all. However, as far as I know, there is no formal method of treating such material. It would be useful if methodologists would offer an opinion on whether the practical problem of the causes of preterm birth could be helpfully approached by the accumulation of data on the propositions outlined here. In my opinion, critics should not assess these propositions piecemeal, but should consider the whole edifice of propositions simultaneously. Obstetricians who confine their attention to the delivery of babies should extend it to the circumstances surrounding the conception of those babies. For there may lie the solution to the problem of why boys are more likely to be preterm than girls.