How We Calculate Due Dates
The general assumption now is that a woman should have a baby by 40 weeks gestation. This is based on a decades old assumption that is not necessarily based in fact but rather tradition. The method of calculating due dates most commonly used is known as Naegele's Rule and you can read more about it here.
- If you read the description you will find that: There are some imperfections in it that make it more of a rough estimate than an exact calculator
- Recent studies have shown that the average gestation is closer to 41 weeks and one day for first time mothers rather than 40 weeks.
What is the big deal about being post dates?
Officially you are not actually overdue until you go past 42 weeks! Yes- read that again- you are not overdue until you go past 42 weeks. Yet currently you will have a hard time finding a care provider that will "let" (I hate that term) you go past 41 weeks. So now, instead of 40 weeks being considered an average, give or a take a few weeks, you pretty much are expected to deliver by 41 weeks or induction is on the horizon.
What is going on here? Truthfully there are some risks to going overdue, they are however statistically small for most women. In fact, one article I found stated that: