Christmas Baby Boomers

Maybe it's the time of year of something, but everyone seems to be telling me that they're pregnant (or their wives/partners are pregnant).

"Merry Christmas!! Oh by the way, I'm going to have a baby!" Next in line, please!

What happens in September to allow this 3-month 'big reveal' around Christmas time? I guess down here in the Southern Hemisphere, spring is well and truly springing at that time of year.

I have to wonder if human reproduction is cyclic, in that conceptions occur with the seasons, as they do with other animals. When do humans have the most 'successful' sex? In the USA, most 2010 births occurred in September, with August not far behind. Perhaps this little mystery of life can be explained by the 'warm and cosy' feelings that are stimulated during the early winter months as we  move indoors. (Presuming you're fortunate enough to have good insulation and heating facilities, that allow you to 'turn on' the heat, that is.) If this argument does hold true, then we Southern Hemisphere-ers would expect births to peak around December/January, 9 months after our late autumn period. I have not yet managed to find this birth month statistics from the Australian or New Zealand statistics websites, so please enlighten me if you are more successful.

In any case, my observation of increased Christmas pregnancy rates from close friends here in New Zealand does not support the 'warm and cosy winter sex' conception argument, but rather a 'yay it's warm enough that I feel alive again after winter'. Whatever the case, I doubt that human seasonal reproductive cycles are as simplistic that I can discuss it aptly here. Indeed I can image many other possible biological causes for seasonal variability, such as optimal sperm temperature and environmental contaminants for example.

Far more likely, my current observations of increased pregnancies most likely reflects the increasing age of myself and my peers as we move into 'that stage of life'. What's more, as a slightly older PhD student, should I myself suddenly fall pregnant today, I am now statistically the average age of first-time mother, and above the ideal age of a first-time mother.



This very knowledge does concern me somewhat, especially considering I have no short-term plans for such an event, which will put me well into the 'increased risk of birth defects' category if it ever does happen. I imagine then, that my pregnancy observations not only in friends but in random women I see on the street, reflects a form of confirmation bias, where I am justifying my own fears about mortality and the unwanted inevitability of reproduction.

Merry Christmas everyone + 1!