The time of pregnancy is calculated from the first day of your last menstrual period (LMP), which is typically two weeks before conception actually occurs. This means the first two weeks of the 40-week count are before fertilization, during which your body prepares for ovulation and a new cycle begins

    • dfyx@lemmy.helios42.de
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      2 days ago

      So? It’s not like pregnant women are planning weeks in advance for an exact date to give birth. An estimated due date is exactly that: an estimate. I don’t have exact statistics on hand but if I remember correctly, your 10% are even a bit high and it’s more like 3% on the exact date. But about 50% are within +/- one week of the original due date and 80% are within +/- two weeks which is pretty good accuracy for a 40 week time span¹. If you adjust based on ultrasound results, you can get even more accurate estimates but the original due date gives you a good timeline when those ultrasounds (and other examinations) should be done.

      ¹ seriously, try estimating any other 40 week project to within a week with 50% accuracy.

      • hitmyspot@aussie.zone
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        1 day ago

        Oh, I get that. The point is that it doesn’t really make a difference for the woman or the healthcare delivery if it’s out be a few days due to sperm migration or being unsure which activity caused conception to occur.

        However, it makes sense from a biological point of view to track the full pregnancy. From egg release onwards. Without egg release, there is no pregnancy. Without fertilization, there is no pregnancy.

        It also makes sense to have it be standardized across disciplines. There is no logical reason to change it from its current definition. It’s not perfect currently, being an estimate, but it’s the closest we have.

        However, what is importtfrom a reproductive rights point of view is for people to understand how little time there is to make a giant decision about whether to abort or keep the baby. Often there is just a 2 week window, which in that time there needs to be a doctor’s consult and a procedure scheduled, irrespective of work, family, health, study or other commitments. When people hear 6 weeks, they think that’s a reasonable time frame to make a big decision and arrange it. When it drops to 2, that’s different.