Like most women in their third trimester, I often wonder when I will go into labor. Hopefully not anytime soon! I have friends who went into labor at 36 weeks and women in my yoga class a week overdue on the eve of induction. And many of you have shared in the comments that you or a close friend delivered at 26… 30…32 weeks (thankfully to healthy babies.) I think we all know the “due date” is just a guess – based on a number of factors and definitely not a date to get too attached to.
I did a little research on due date background and found Naegele’s Rule of a 280 day gestation from the last normal period or 266 from ovulation. The numbers have held up in a few studies with 280 (281 for first time moms) days of gestation with a standard deviation of anywhere from 7-13 days. But his rule is also based on a 28 day cycle and ovulation on day 14, which I did not have!

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This article states that induction rates have doubled in the last decade but after delivery it’s determined that over 70% of these women aren’t even “overdue” at time of induction due to incorrect due date calculations! Ina May talks about this in her books as well. My doctor has said my practice induces at 41 weeks.
Thinking back to the cycle I conceived…I didn’t ovulate on day 14. It was actually day 24, or 10 days beyond average.

If you use my last period date alone, my due date is way off – and I might have been one of those induction cases! Luckily I was charting and using an ovulation predictor, so I’m fairly confident in the date of conception, give or take 24 hours. When I first got a positive test, I plugged in the ovulation date, not the last period start, into the calculators and got to August 31. My ultrasounds have matched gestational age nearly to the day, which further confirms my ovulation-based EDD. And luckily my doctor has put August 31 in my chart as the “official” EDD. He agrees with my assessment.
I doubt my mom’s labors really have that my genetic influence, but my sister and I were both early by a few days. Matt was right on time.
It would seem that whatever it is that determines when labor starts would start counting from conception. I believe that the baby’s gestational age and physical maturity trigger a hormonal release that it’s time to come out that starts the domino effect that puts a woman into labor.
But what if counting starts with egg age? What if since my egg was 10 days older than the typical cycle it thinks it’s ready sooner? And what if somehow that hormonal release is triggered by the date the egg decides it’s the primary one and not the conception date? [Gosh my brain hurts from trying to recall the female reproductive cycle details…] I don’t think the baby would release the hormones if he wasn’t ready to come out, but it would explain why there is such variation from baby to baby.
For all of these reasons, I’ve been having a gut feeling that I might go into labor early.
However, I think this could also easily be my anti-procrastining, type A self being worried that we’re not ready yet! Or residual worry from those 2 weeks when I was a little concerned about cervical incompetence (which was since found to be totally normal). I’m not putting too much confidence in the gut instinct.
Please note these are just some ponderings and not something I’m obsessing about….but as August 31 gets closer, or really just as August gets closer, I can’t help but wonder what my body will do! I HOPE I go to 40 weeks because that will be best for the babe! August 26 would make a lovely birthday. Karen’s birthday is September 1, so she’s rooting for a grandson as a birthday present. And finally having a baby on Labor Day would be pretty fun too : )