How accurate are due dates given by ultrasound measurements? I've been told 4 different ones at first i was measuring small edd of feb. 19 then i was told feb. 25 and then feb. 27 now im 34 weeks and the baby and i are both measuring 36 weeks which puts me at feb. 4 and the baby is in head down position, im so confused!! Anyone deal with this?

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Jessica - posted on 09/08/2012

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i have a question moms, my due date is march 27,2013 everything on the net says my LMP was around june 22nd but i didnt get my period in june, so did i get pregnant in june?

Ashley - posted on 01/22/2009

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I had this problem too, not that many times though, first the dr told me i was due sept. 19th then the next 2 ultrasounds said Sept 11th and he finally came on sept 21st...so i guess its really whenever there is ready

Connie - posted on 01/10/2009

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i am a sonographer and my advice to you is this: the baby will come when he or she is ready. the due dates that we give you is an ESTIMATED delivery date. as long as the dates are within the two weeks before or after the due date they give you based on either your last menstrual period or your very first (8-12 weeks) ultrasound. its hard to know when we ovulate or conceived...that's why we have 40 weeks of pregnancy (that's 10 months, not nine!) don't worry about the exact date...a couple of days or up to 2 weeks is not to be concerned with. good luck with your pregnancy.

Casey - posted on 06/25/2012

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I am going through the same thing right now. According to my cycle I am due September 25th but the ultrasound has the baby due on October 3rd. I have one doctor that refuses to change the due date even though the baby's size meets the criteria for changing it and then there is another doctor that wants it changed. Not only that but the baby will be born c-section and so they will deliver up to a week early but they want to avoid an emergency c-section at night or on the weekend so now there is talk of moving it up another week. With all the confusion going on I'm not sure when my baby will be born at this point.

Alisha - posted on 01/10/2009

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i would go my the ultersound pic myself.  When u first find out ur prego it goes by the last period right so ur kinda just guessing i think.  For my first i had the first guess and then the ultersound and we went byt hat one and well she came on her due date :D  my second one wehad 3 due days. . .the 10, 17 and 27. . how they got those who knows but we went by the ultersound pic which said the 17 and she came on the 20.  So i think the ultersound knows compared to a guessing.  Good luck and just prepare urself

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Casey - posted on 06/25/2012

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I am going through the same thing right now. According to my cycle I am due September 25th but the ultrasound has the baby due on October 3rd. I have one doctor that refuses to change the due date even though the baby's size meets the criteria for changing it and then there is another doctor that wants it changed. Not only that but the baby will be born c-section and so they will deliver up to a week early but they want to avoid an emergency c-section at night or on the weekend so now there is talk of moving it up another week. With all the confusion going on I'm not sure when my baby will be born at this point.

Richelle - posted on 01/22/2009

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I had the same problem. My due date changed three times. I knew the date of conception, but they wanted to go from the first day of my last period. I counted 40 weeks from date of conception and I was 1 day off, they counted from the first day of my last period and they were 9 days  off!  If you know the date of conception try that. Congrats!

Natasha - posted on 01/11/2009

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i was given 3dates 2start wiv as it was unsure when i conceived as i came off the injection just 3months b4 and things werent bk 2normal. i was small all the way through my pregnancy but the midwife never said anythin, none of my neighbours even guessed i was pregnant even 5weeks after i had my baby because i was so small and he was a very quite baby that no1 realised. he was born on the last date i was given so 2them he was born on his due date and he weighted 8lb 6oz which no1 wud hav guessed as i was so small, i still think myself the date was wrong and that i was 2wks over due. your baby is gonna arrive when he/she is ready and hopefully everything will be fine but all u can do is make sure u hav everythin ready and take things easy, if this is your 1st then dnt 4get u cud still b waitin 2wks later

[deleted account]

With my son, my due date according to my last period gave me an edd of August 22. My first ultrasound at 16 weeks gave me an edd of August 16. I had another ultrasound done at 20 weeks because they wanted a higher level scan done on the baby and my due date got moved to August 10. He was born on August 7.

Jennifer - posted on 01/11/2009

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Yes, my secomd daughter had about four different due dates. My Dr. just finally took the one in the middle (they were only apart by a couple of days) and stuck with it. At best these are only estimates and the baby will come when ready.

Betty - posted on 01/11/2009

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Things may have changed since I had my son but they were way off with the ultra sound. I was told he was only a couple of pounds a week before he was born Ended up he was 6lbs 4oz and 3 weeks premature. I wouldn't worry about the dates when baby is ready baby will be born.

With my daughter I was told she was due the day after the ultra sound but wasn't born for 3 weeks.

Karen - posted on 01/10/2009

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I'm with Angie....babies are going to come when they are ready.  All you can do is wait.  Pray for a healthy baby and a good delivery.  Good luck & God Bless!

[deleted account]

I had the same thing happen to me.  At 38 weeks I suddenly jumped up and they sent me for an ultrasound but they didn't change the date.  My son was born 2 days after my due date but they also used the date of my last period to figure my due date because we both measured big the whole time.  



I do have one peice of advice and that is to find out how long after your due date they will let you go before they induce you.  I DID NOT want to be induced if at all possible so I was interested to know how that works.  Usually as long as you and the baby are doing fine they will let you go 2 weeks past your due date.  Good luck and congrats.

Carol - posted on 01/10/2009

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With my oldest son, I didn't have an initial sonogram. This was back in 2000 when I found out I was pregnant. They went off my last period and gave me a due date of May 24 and he was born May 27. With my 2nd, I found out I was pregnant in May 2006 and at my initial appointment, they did an internal sonogram and gave me a due date of Jan. 9th. Well, at the appointment after my 20 week sonogram, the midwife changed due date to Jan 18th. At the next appointment, the OB said she didn't know why she changed it because based on the initial it should have been the 9th...so she changed it back to the 10th. Well, he was born on the 12th. As for measurements, there were times I measured large at one appointment and then the next wouldn't change much. Also, don't listen to them when they say how much the baby weighs. With my first, doc told me he'd be 8 lbs...he was 6 lbs 13.5 oz. With my second, right before I pushed, midwife said 7-7 1/2...he was 6 lbs 10 oz.

Cari - posted on 01/10/2009

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I just read your last comment LOL! My daughter Devin had really long legs and was the same scenerio but still the first ultra sound was the closest.

Cari - posted on 01/10/2009

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yes I had 4 kids and the first due date was always the right one or closest to the right time: )

Codi - posted on 01/10/2009

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Maybe I should mention my doctor was concerend when i went yesterday because ive been measuring right on track then suddenly jumped ahead 2 cm so she had the ultrasound done and that also said the baby was 36 weeks 51/2 pounds (with really long legs funny) so they are staying with the 19th but basically i could go anytime in feb. also my periods were never regular so im not sure when my last one was so of course i couldnt go by that im just curious about all this.

Shannon - posted on 01/10/2009

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I'm a nurse, and I can tell you absolutely that the first ultrasound (6-10 weeks) is the most accurate.  Due dates figured by ultrasounds  later in pregnancy can vary by up to 2 weeks, and aren''t accurate.  The fact that you are 34 weeks, and measuring 36 means that you are right on schedule.  Your very first due date is the one to go with, and a few days difference really means nothing.  Remember, it's just a date, and only a small percentage of babies are born on the actual day.  The measurement they take is from the pubic bone to the top of the uterus (fundus).  This is measured in cm and after 20 weeks gestation the number of weeks should be on track with the cm measured. (i.e.-at 20 weeks, measuring about 20 cm from pubic bone to fundus).  This, too, can vary by 2 weeks.  Everything sounds like it's right on track for you!  Good luck!

Christina - posted on 01/10/2009

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They aren't accurate at all really.  With my son the first due date was March 24 and they used the date of my last period. It got changed April 24 when they did my ultrasound.  I had my son on May 3 and he was in there so long there was no more fluid.  He was covered in infection, his body temp was too low and he had low oxygen.  It was really scary. Most good docs will never change a due date from an ultrasound because babies come in all shapes and sizes. Go by the date of your last period as your guide...and your instinct :)

Jennifer - posted on 01/10/2009

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The due date is estimated by the size of the baby, so it sounds like you are going to have a big baby!  The baby won't listen to anything the doctor says anyways, so he/she will come when ready . . .

Chantel - posted on 01/10/2009

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My doctor told me I was due March 23 but the ultrasound tech said that based on the measurements on the first ultrasound I wasn't due until April 7. My doctor disagreed and told me he still said my due date was March 23. Well, March 23 came and went and I didn't go into labour. I was HUGE and uncomfortable but because of the ultrasound measurements they would not induce until 10 days after April 7. I never went into labour and they finally induced me and My 9lb 3oz baby girl was born on the 17. I had got an ultrasound on March 25 to check the baby and the tech said she was pretty sure the baby was already about 8 lbs then. She was also head down in the birth canal for the last few weeks so it still might be a bit for your baby to come.

Bee - posted on 01/10/2009

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I was told the same thing. You will know it 1) when ur water break 2) having pain like contractions 3) having to go to the bathroom #2??

Leigh - posted on 01/10/2009

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I  had the same situation with my first son.  All the doctors told me different dates because of his size.  The date's kept moving up.  He was almost a month late, from the doctors date.  They told me He was due on the 4th of aug, or sooner.  He was born on the 23rd of aug.  Your best bet is to think hard about when your last "monthly" was, and then add 10 months.

Lisa - posted on 01/10/2009

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i wouldnt go by them all the way through they told me i was having a big baby i went 16 days over and he was only 6lb12oz

Wendy - posted on 01/09/2009

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Typically, your first ultrasound is the most accurate since babies tend to develop pretty consistently the same at first, but grow at different rates later. I've had 5 kids, and all of the ultrasounds were ALL over the place. 1st one was always the most accurate. Had each 10 days early TO THE DAY. Best adivce I can give is trust your instincts more than anything else. Better safe than sorry.

Molly - posted on 01/09/2009

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I was also told a few different dates....Altought I had a small problem and had to be put into labor, but my little girl was 2 weeks earlier then my earliest due date

Bec - posted on 01/09/2009

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P.S. my 1st was 2weeks past due date, my 2nd was 4 days late and my 3rd was a guess.... When bubby wants to come they come...

Bec - posted on 01/09/2009

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Hi, When I had my 3rd bub I was told 4 expected dates also, then a specialist said to me that the most accurate was the ealiest scan as they could predict measurments the best. But as always my 3rd came when she wanted to but it was only 3days after the ealiest scan due date.

Paulette - posted on 01/09/2009

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Hi Codi,  I know it is confusing...but first thing to figuring it out. If you know the date of your last period....then take that and count backwards by 3 months. Here is an example....If the date of your last period was January 5, then count back 3 months, it would come to Oct. 5. So the expected due date is Oct. 5th...give it 1 week before or after. That would be because you can never tell 100% when the baby is going to come. I would think back to when you concieved....If you go with the Feb. 19th date....that would mean you conceived close to May 19th. With going with the date of Feb. 19th...a doctor will tell you to that the baby could come 2 weeks b4 or 2 weeks after...with that line of thinking...Feb. 5th would be the earlier possiblity. March 5th would be 2 weeks overdue. I would go with the first due date they tend to be the closest. Oh I also wanted to tell you that a woman ovulates between her 10th and 14th day in her cycle so that can help you narrow it down too. So the date of your last period started + 10-14 day window. Here is an example that goes with the first one I gave....Jan. 5th was the first day of 'the last period', the ovulation window was Jan. 15th-19th.



So, the way you're measuring it could mean many things. But trust you instincts. It would fit into things if you go by the first due date. It would put you early but if this is your first you can not be 100% positive anyhow at to when you'll go into labor. I was dialated 2cm in the middle of Dec. with my first and did not go till 3 days after my due date in Jan. It seems that woman get this burst of energy and clean/decorate like crazy to prepare for the baby about 2 weeks before. That is what I have seen, heard and experienced. When the belly drops the birth is pending too. With the baby being head down position, is usually in preparation for delivery. There have been cases where they have changed again but that is rare. I would pack your bag and relax. Enjoy yourself and the daddy, things are going to change a lot. If you do not know what to pack and would like some tips, just ask. Take care and have fun, enjoy. There is no other day in you life that will be as special as the birth of your child.

Dawn - posted on 01/09/2009

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i was in your same position as you back in 2006. i ended up with a due date of valentines day and had my 1st son on the 22nd of feb. ultrasound measurements are fairly accurate however i would just trust your Dr. Trust him or her to take good care of you and your child. if you are worried about going into labor get a plan ready. get your bag packed and in a spot to grab it as you walk out the door. also ask your Dr. which due date to go with.

Angela - posted on 01/09/2009

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I don't know the stats.... but I do know that I did not  know my conception date and my Dr. swore up and down from the beginning I was due Jan 10. I never thought that was right.... when I was about 36 weeks they decieded that my son was big..



He was born on Dec 25 and weighed 9 lbs... I think he was ready to join the world....



I personally don't know anyone that had their child on their due date... there comes a point when you have to accept that this child will come into the world when ever he/she darn will pleases. They are all just guesses.



My OB did tell me several times that the bigger they get the more difficult it is to determine the due date. He always liked the 5 week size because there is less varation from person to person earlier

[deleted account]

Codi, typically the earliest ultrasound (8-10weeks) is the most accurate for setting due date, as you get into the second and third trimester they are not as accurate for setting a due date. If you are 34 weeks and measuring 36 cm that is not all that off, typically when someone measures larger then due date they will compete an ultrasound to see how the babies growth is measuring if good, you have nothing to worry about. You can be larger then dates for many reasons, bigger baby, babies position, too much fluid etc. But measuring larger at 25, 27, or 34 weeks should not change your due date. I would speak with your OB and find out what date they are using for your due date so you can put your mind at ease. Good luck with your upcoming delivery. Cindy

Angie - posted on 01/09/2009

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well generally speaking this baby is going 2 come whenever he or she is ready no matter what, so i'd get everything ready if i were u!! haha..and usually the earlier the ultrasound is, the more accurate it is..the later ones aren't as reliable..all that matters is that u both are healthy & there's plenty of fluid in there..but get prepared, just incase!!

April - posted on 01/09/2009

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I had this same problem. I was first given a due date of September 3rd, then September 14th. When I had the first ultrasound I was told I was 12 weeks, but the actual ultrasound picture said 14 weeks. My son ended up coming on September 1st, which would make 38 weeks if I went by the 12 weeks that the technician said, or 40 weeks by the 14 weeks stated on the ultrasound photo. It's frustrating that it's not really an exact science.

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