are due dates a load of bollocks?
It might surprise you to know that due dates are not based on any credible scientific evidence.
The 40 week due date theory originates from a Dutch Botanist, Harmanni Boerhaave, who drew "evidence" from the Bible which states that human gestation lasts approximately 10 lunar months.
With the way some people go on about them, you would think that due dates are based on some very clever, scientifically proven formula which can predict the optimal day for your baby to be born… but no.
In fact, large studies have shown that for first time parents, the average time of gestation is 41 weeks and 1 day. So it makes no sense to fixate on the 40 week mark, especially since your predicted due date can vary depending on where you live!
The 40 week due date is based on a lot of assumptions, and not very much science. After Boerhaave came Franz Naegele, a German obstetrician who came up with the formula that we use today to predict due dates.
Naegele’s rule, as it’s called, assumes that all menstrual cycles are 28 days long, and that ovulation occurs exactly on the 14th day of your cycle. According to Naegele, you can estimate your due date using this information, by adding 7 days to the first day of your last period, and then counting forward 9 months.
But of course, we know that menstrual cycles can vary in length – we are humans, not robots! And as with all matters of the body, there is rarely a “one size fits all” method, so why do we expect pregnancies to last a specific amount of time, and why do we send pregnant people in to a panic if their pregnancy lasts any time beyond this?
The reasons are many, and they also vary, but what is important to note here is that going over your due date alone is not sufficient reason to begin interfering with your pregnancy. By knowing the origins of the due date, we can see that they are not based on concrete scientific evidence, and therefore we have more information to guide our decision making process, and feel more confident in choosing whether or not to choose interventions.
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