or Connect
Mothering › Mothering Forums › Archives › Pregnancy and Birth Archives › Due Date Clubs 2009 - 2012 › February 2010 › Due date based on ovulation more accurate?
New Posts  All Forums:Forum Nav:

Due date based on ovulation more accurate?

post #1 of 15
Thread Starter 
My due date is based on my ovulation date. I was charting, etc so I know exactly the day I ovulated. Does this mean the due date is so accurate, the baby won't go overdue?! Probably just wishful thinking....! Anyone else have an experience in the past with a due date based on ovulation? What happened?

I was thinking, are babies overdue because they just stay in longer than whatever the supposed gestation is, or because the due date was not accurate...
post #2 of 15
I think that if you know your ovulation date the due date can still be off by as much as two weeks in either direction depending on the baby, your body, etc. It makes sense to me even though doctors say 40 weeks, but really anything 38-42 is completely normal. Some babies need more cooking time, some less.
post #3 of 15

I lied

My lmp was Apr 6 but I ov'd on May 1 and DTD. I told the midwife group that I did NOT know my LMP because I knew my exact ov date. I also didn't test positive until May 17th. I gave them that O date, refused the dating sono and my measurements are tracking exactly on the schedule I gave them for my Ov date.

I don't know if this will influence when labor is or gestation as I had a 37 day cycle which may influence length of time the bun is in the oven--gestating longer than 40 weeks. My last boy was 42 + 3 based on LMP so I can't know whether gestating based on O date is more accurate. However, I do know that I want the longest gestating period they'll give me so that they will stay off my back about induction, size, weight, yadayadayada.
post #4 of 15
I had long-cycles (35 days) when I got pg with DS1, and I knew exactly when we had conceived (I wasn't charting, but DH was on tour with his band for three weeks, and I was a little excited that he was home, so it wasn't hard to figure out ), all of which influenced me to believe that baby day would be considerably farther away than my LMP EDD, and maybe even my u/s-based EDD. He ended up coming four days later than my LMP EDD, and two days earlier than my u/s-based EDD.

With DS2, I had weird looong cycles (AF came back at 13 months, and I had like three periods), one that was 60 days, we *think* that we conceived about 3-3.5 weeks later (this time, I was the one out of town for ten days, visiting family, and it either happened before or after that trip, but we were never really sure, lol)...he also came four days after my LMP EDD.

This time, I'm really interested to see what happens. I had a miscarriage in May, and we conceived right away, before I had a period, so my m/c date is my "LMP" date. It's hard to know when I ovulated, but since that has proven to not make me do that much later in the past, it will be interesting to see how much it matters this time.



So, all of that to say, that IME, you just have a certain baking time, and ovulation doesn't really play that big of a determining role. I do believe that everyone has a different gestational time, somewhere between 38 and 42 weeks, give or take.
post #5 of 15
With both of my pregnancies, I was charting, temping, all that good stuff. With my first, I delivered 5 days past the ovulation estimate and 7 days past the ultrasound estimate. This time, my ovulation estimate is Feb 2nd, and my ultrasound estimate is Feb 11th. Of course now, according to ultrasound, the baby is measuring 4+ weeks ahead, so who knows what will happen!!
post #6 of 15
If you know when you O'd then yes, that is the most accurate assessment of your due date. HOWEVER, that doesn't mean that you'll pop baby out on or before 40 weeks by that date - babies aren't time bombs. Like was already said, average gestation is 38-42 weeks, and you could fall anywhere in that window.
post #7 of 15
this is my first but this is how I understand it: If you know your exact ovulation date ( I do also because I was charting) then you know when you reach the 40 wk mark. but I think 41 or even up to 42 weeks can be completely normal of a gestation period. So knowing your ovulation gives you a better idea of where you are with it, but I don't think all babies gestate exactly and only 40 weeks! Some go less or more.
post #8 of 15
If you know your actual ovulation or conception date, it's more "accurate" than going based on LMP. Just keep in mind that when calculating from your ovulation date that your "due date" is 38 weeks from then, not 40. 40 is only counted if doing it based off of LMP because textbook cycles are 28 days with a luteal phase of 14 days (which lots of us ladies don't have).

Going based on conception, the "normal" birth window is from 36 weeks gestation/38 weeks pregnant (2 weeks "early") to 40 weeks gestation/42 weeks pregnant (2 weeks "late").
post #9 of 15
Just want to agree with everyone else. It's great you know your O date, but it still means the baby could come anywhere in the timeframe +/- 2 weeks just because babies are all different.

I do know my exact ovulation date b/c I was being treated by my Naturopathic Dr. for annovulation and was temping and all that good stuff. My O was the first one in over a year!! That said, I jumped the gun and tested early (WAY early... as in the evening of 8 days past ovulation) and got a very faint + which makes me think that implantation maybe happened about as fast as it possibly could and I also think my obvious/drastic temp shift happened a couple days after my ovulation date - which would line up better with the days we were intimate - I know sperm can live a long time, but if my temp shift was my actual ovulation date Dh has super sperm and I have a very hospitable body (which doesn't bode well for my plans to do NFP as birth control in the future...).

I was also immediately blood tested so the ND could run my hormone levels so she did the beta/hgc test too and it was quite high at 12 days past my temp shift. All that could mean nothing, but at my only ultrasound I was measuring about 5 days ahead. Not enough to change my due date, but I have consistently also measured about .5-1 week ahead in my fundal figures. So... I guess I just want to say even with a positive ovulation date (based upon temps) there is still some wiggle room in exact dating.
post #10 of 15
I really think that all women and babies gestate in different time frames. But, also think having your exact dates are important, because I supposedly went 2 weeks over with dd, but She was only 7.12 and had tons of vernix my placenta looked like a term or placenta, not a 2 week over one... so I think having a more accurate date is important.
post #11 of 15
The EDD that my OB gave me and the EDD that I came up with based on the day that I O'ed are only off by 2 days! So, he'll either be a February baby or a March baby. We'll just have to wait and see.
post #12 of 15
The O date will be more accurate, but it still probably won't tell you when exactly the baby will be ready.

I've been able to feel ovulation since my cycles came back after my first child, so I know the O date with these last three. All my kids so far have been born between 38 wks 5 days and 38 wks 3 days. My sister has known the O date for all four of her's and three of the four have been "overdue" by about two weeks. We joke that they get 40 weeks by averaging out the two of us.
post #13 of 15
Quote:
Originally Posted by Katie34 View Post
this is my first but this is how I understand it: If you know your exact ovulation date ( I do also because I was charting) then you know when you reach the 40 wk mark. but I think 41 or even up to 42 weeks can be completely normal of a gestation period. So knowing your ovulation gives you a better idea of where you are with it, but I don't think all babies gestate exactly and only 40 weeks! Some go less or more.

BUT, just in my personal experience, my friends who charted *did* seem to deliver closer to their O-based due dates. I delivered right exactly on mine.
post #14 of 15
My LMP due date is Feb 18th, my ovulation due date is Feb 26th. I've been going by the LMP due date because it's sooner! My midwife has both dates, so we can use whichever one is more convenient.

With my son, I wasn't charting, so I only had the LMP date - I've always had long cycles, so the ovulation date would probably have been later. But my son came 8 days early based on LMP. So we'll see what this one does.

I expect a baby sometime between late January and early March. (I'm voting for February, though!)
post #15 of 15
My LMP Edd is like January 20 or something like that. My O date is either Feb 5 or Feb 8 as I had a double dip lol. I made the OB do a dating U/S bc we were using a military treatment facility back in the states and I DID NOT WANT to be induced two weeks after January 20. So they agreed and at 5.5 weeks it measured at Feb 5. In Germany they would have accepted my O date based on temps but not in the US.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: February 2010
Mothering › Mothering Forums › Archives › Pregnancy and Birth Archives › Due Date Clubs 2009 - 2012 › February 2010 › Due date based on ovulation more accurate?