The length of pregnancy is a fascinating topic to me because, if you’ve ever been pregnant, 40 weeks seems like a really long time and calling it a “guess date” is a little frustrating when you might need to plan things around that due date (ie. if family needs to take time off to visit and needs to give advance notice at work). I’ve heard a lot of women opting for inductions and c-sections because they want to know when their baby will be born. I think medical interventions should be saved for the times they are genuinely needed, but I GET where they’re coming from. If I go into labor for my VBAC (vaginal birth after c-section) and end up needing a c-section, I have no guarantees that we’ll have family available or able to take off work at that time to come help out. My husband gets paternity leave (yay!) so it should be fine, but if he didn’t we would probably be in trouble because for a few weeks after a c-section you’re pretty much out of commission. Not great with a newborn AND a toddler. Having family around to help is nice and with so many people like us who have family living long distance, it’s hard to figure out what to do when you don’t KNOW your due date or what kind of help you’ll need.
Today I saw this really interesting article on the Length of Pregnancy; it’s not good news for us mamas who would reallllllly like to KNOW, but it’s interesting anyways. While they used to believe that the up to 5 weeks variation in pregnancy length was due to miscalculations of ovulation, this study actually tested women to determine exactly when they ovulated. Neat! Not sure why no one thought of this study before though…?
Main Points from Article
- “A woman’s due date is currently calculated as 280 days after the onset of her last menstruation and is only ever considered a best guess. Only four per cent of women deliver on their due date and only 70 per cent within 10 days of it.”
- “…average time from ovulation to birth was 268 days – 38 weeks and two days”
- “The length of a pregnancy could be affected by a number of factors. Older women tended to deliver later, while women who had themselves been heavier at birth also had longer pregnancies.”
Link to the Original Article: Length of pregnancy can vary by up to five weeks, scientists discover
We could also calculate it with the general standard, 280 days after our last menstrual period. Here is a link to a calculator from BabyCenter to help you figure out that date.
I’ve been just saying that K will be here in early November as this seems to be the safest thing to say. But just for fun, I did some math! Haha. If you didn’t read my earlier post about my issues with doctors and their tests, here it is. To summarize, my old OBGYN (who I fired not for making the mistake, but for their really terrible way of letting me know then lack of communication when I had questions) told me I wasn’t pregnant at the beginning of the pregnancy. Awesome stuff. I have more information from this pregnancy than I do about G’s pregnancy as a result.
- Based on 268 day average: EDD would have been September 29, 2011 (based on ovulating 15 days after LMP)
- Based on the 280 day LMP estimate, his EDD was September 26, 2011.
- With G I didn’t have a dating ultrasound until 12 weeks, I believe, which may not be as accurate as an 8 week ultrasound (it was also external), but according to that estimate his EDD was September 23, 2011.
- Based on 268 day average: October 13, 2013 (or if you use my phone’s ovulation estimates, October 20 or so).
- Based on 280 days standard: October 10, 2013
- Based on my 7-8 week ultrasound: October 31, 2013 (this is my official due date because it’s the most accurate means my midwives had of determining EDD that actually has better).
- My OFFICIAL guess for due date is October 15, 2013. Why? Because the 268 day average was most accurate last time and one day short, PLUS that’s my birthday. So it sort of qualifies for the “holiday” status too. I know I added an extra day just to make it on my birthday, but yeah. That’s my guess!
- Daddy B’s OFFICIAL guess for due date is October 20, 2013.