Do you think individual women’s fertility varies by time of the year?
It seems like siblings who share a birth month are more common than would be expected by chance (wrote the mother of two April babies.)
On the other hand, since there are only 12 months in the year, this should happen fairly frequently.
Overall, in the United States, birth rates peak for northern states during the spring and summer and in the autumn for southern states according to one recent study, unless you are Amish. (I doubt any of our readers are Amish, but perhaps you enjoy reading about them, as I do.)
Meanwhile, in Europe, births now peak during the last three months of the year, and the reasons of this were perplexing to the authors of one recent study.
Many theories have been put forth to explain birth seasonality, related to differences in air pollution, nutrition, levels of viruses like influenza, and air temperature, to list a few. None has been clearly proved, from what I could glean.
And none of this explains whether individual women are more fertile at particular times of the year, or whether siblings are born in the same month more often than would be expected by chance. Currie and Schwandt published an article last year showing the individual women’s characteristics do have a strong association with timing of pregnancy. In a finding that strikes me as completely counterintuitive, birth timing varied notably by women’s race, educational level and socioeconomic status.
Perhaps this is the takehome message: you can chart your temperature and your cervical mucus all you want, but remember that there are poorly understood environmental factors at play, and they also seem to influence the outcome.
Also, none of this explains this widely observed phenomenon: if you’re trying to conceive, and you go shopping at Target, if will seem like every third woman there is pregnant. Just wanted to warn you about that.
If you want summer to be your season of pregnancy, but apparently it’s not, you may feel disappointed. First, try to remember not being pregnant during the summer has some upsides.
Let’s list a few here:
Finally, especially if you live in the northern United States, remember that your chances of getting pregnant during the summer are better than average! Elevate those hips! Or don’t.
On the other hand, some our readers are pregnant now – and apparently especially those of you living in the South. Congratulations to you! Enjoy eating ice cream and feeling lighter while swimming. (Hopefully you were able to find that suit on sale.) Look forward to either autumn baby strolling, which is lovely, or being really pregnant during the colder months, when that fetus will keep you nice and toasty.
And Happy 4th of July to our American readers!