incorrect due dates, u/s, anyone?

Has anyone had varied due dates, are u/s the most accurate?
As I have PCOS and had not had AF for quite some time and then fell pregnant, we had no dates to go by, only what ultrasounds told us. My 1st u/s I was told less than 3 wks, come back in 6wks, so that would have made me less than 9wks, so the u/s told us I was nearly 12wks. So since they have been measuring me at each appt, I am told each time 'you are having a big baby, watch what you eat, reduce carbs etc' and I am getting a little sick of it as I am very very careful with what I eat and I have a gut feeling I am more like 38wks than 36wks. SO which is more accurate, u/s or going by AF dates? Does anyone have any similar experiences?
Thanks

Hi there,

Ovulation is a more accurate method for determining your estimated your due date than ultrasound scans - that is, 38 weeks from ovulation. This is also more accurate than counting 40 weeks from the first day of your last menstrual period as many women with irregular cycles do not have 14 days (2 weeks) between start of LMP and ovulation.
Unfortunately if you are unsure of when ovulation occured then the scans will be your next best predictor - but keep in mind that statistically, only 5% of babies come on their due date! Do you having a feeling or a sense for when you may have conceived/ovulated? This again may be more accurate than your scans which, yes - tend to vary at each subsequent appointment. But keep in mind that all methods provide an estimate only!

To be honest - many women on here will tell you its actually a good thing if they are predicting your gestation to be less advanced than it is - as this equates to a later EDD, and subsequently less pressure on you to induce due to being 'post dates'. Remember that the normal range for pregnancy is between 38 - 42 weeks, and there is no need to consider induction without a serious medical reason to do so until such a date has been passed. Having a 'big baby' is also not a valid reason to consider induction - tiny women give birth to 10 pounders every day - the female body is perfectly equipped to do this!!
So if you know that you are eating well and the scans reveal that your baby is fine - then ignore the negative comments - you need to surround yourself with only positive energy right now!!

At the end of the day, no matter how many methods of predicting your due date you are able to utilise, your body will go into labour when your baby is ready to be born, and that 5% accuracy rate should tell you that babies have little regard for arbitrary timetables set by medical staff and scanning machines!! They know better!! ;)
My best advice is to honestly forget about the estimated due date. As long as you are prepared for labour with your hospital bag ready to go - there really is nothing more you CAN do.
Just try to relax and wait for the magic to happen - babies take their cue from Mother Nature and they like to surprise us anyway!
Best of luck.....

XX

With my first, I had no dates to go from , so we went by USS. About halfway through I started measuring higher - my GP thought I was further along - but hospital stuck with the scan dates. DD1 was born 2 days after her Scan due date but was waaaay overcooked :lol: So yes, USS can get it wrong.

Having said that, if you hvae no AF dates or O dates, it's really all you've got to go on.

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- many women on here will tell you its actually a good thing if they are predicting your gestation to be less advanced than it is - as this equates to a later EDD, and subsequently less pressure on you to induce due to being 'post dates'.

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- true ;)

I would let the comments about having a big baby go in one ear & out the other... there are so many stories of women being told they were having monster babies, & it never happened... happened to my sister... just relax & enjoy the last of your pregnancy!

I was shocked when I found out I was pregnant as I was not expexting to be as my partner and I were not planning to have children yet, however we are both heaps excited about the pending arrival of our little bundle...

In saying that I was told that I was measuring 27 weeks by ultrasound when there was no way humanly possible (unless it was an immaculate conception) I was that far along. By my last ovulatuion which I am pretty regular on I should have only been about 23 weeks. I freaked out, thinking my god there is something wrong with me, or my baby. They told me all that stuff watch what you eat, dont eat so much sugar all that sort of thing

I have since learnt that it can happen especially since I missed my 12 week dating ultrasound. My utrus is measing the correct date too, so I just like to think I have a pretty healthy baby, but its nice to see there is someone else with a similar story...