answer:Theoretically, there could be some truth there. If you think about all the different seasonal changes, it’s not that difficult to imagine that there would be some effect in utero. Take for instance, viruses. They tend to thrive under certain conditions. Different seasons usually bring particular changes. (ie rotavirus seems to like cold dry weather) If an expecting mother were to be exposed, I’d imagine it would affect the infant in some developmental way. Then there’s food. Certain crops grow during certain seasons. I can also imagine that diet would affect development. And depending on which trimester the expecting mother is in, that would also narrow the exposures along a seasonal framework. That being said, astrology probably “works” because people believe it.