How accurate was your ultrasound birth rate prediction?

[SummerBaby]

Last week, at 31 weeks, my ultrasound revealed that I am carrying a whopper of a baby- the estimate was 5 lbs. This apparently means the baby will weigh about 10 lbs at delivery. Yikes! I was just wondering what everyone's experience with weight prediction was.

Val
DD 2.5 years old
another summer baby coming in 2007!

[SnuggleBuggles]

My OB refused to do a size estimate b/c he said they are just too unreliable. I have heard +/- 2lbs. That is too big a difference to hold any faith in. He just said baby looked like an average size. he was born at 42 weeks 8lbs 5oz. Seemed pretty average to me.

I have links that I can add later about the accuracy of u/s weight estimates.

Btw, you have been through birth before. Even if this baby is bigger there is no reason to think you won't be able to birth this baby even if baby is bigger. Bigger doesn't always mean harder. Position plays a larger role in ease. :) Don't get scared. Just use all this time to figure out tips that can make any birth easier (birth/ labor positions...). It can only help. :)

Beth

http://findarticles.com/p/articles/mi_m0689/is_n5_v46/ai_20766966

[alexsmommy]

Totally off. When my water broke at 30 weeks they thought DS was 4lbs. This meant I could have had the option of delivering at my original hospital (which does not have a NICU but has a 4lb cut off for newborns remaining in their nursery). Luckily I knew enough and my OB was savvy enough to say that this was too risky and we all agreed transferring me to a hospital with a level III NICU was the best route. I wound up not delivering for two more weeks. When DS was born two weeks later he was 3lbs 3oz. I think a lot of docs will tell you the weight estimates from US can be waaaaay off.
Alaina
Alex Feb '03
and #2 in early summer '07

[SummerBaby]

Thanks. My OB said +/- 1 lb. I think I'll be fine giving birth- I'm a large boned person and had DD very quickly. I'm just shocked thinking about a 10 lb newborn! At least that would provide me with an excuse as to why I am so, so HUGE! :)

Val
DD 2.5 years old
another summer baby coming in 2007!

[kijip]

Not accurate at all IME and from what I have seen with friends IRL. One friend was told 8-9 pounds... and had a 12 pounder! Another was told 10-11 pounds minimum and had a not quite 8 pounder. Don't schedule a c-section or something along those lines solely based on the weight estimate. The mother with the not quite 8 pounder had a c-section because the baby was going got be *so big*...and then the baby was smaller than her first child which was an vaginal delivery.

****Rocking out while parenting my smart little munchkin Toby. Just trying to do good in the world, a little at a time. Words to live by: it is *never* the wrong time to do the right thing :)

[JBaxter]

LOL my OB did use the u/s but he told me by feel Nathan was going to be 9 1/2-10lbs and he was 9lb 8oz and 22 in long.

[TaChapm]

With Jackson and Tyler they were pretty close. With Jaci that was another story. On the day I had her I had an ultrasound and they estimated her weight to be around 8lbs. 5 oz. She was born a few hours later at 6 lbs 7 oz. WAY OFF!

Tara

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[megs4413]

off by more than a pound for both kids. the u/s tech in my lasr biophysical profile before DS was born said she asks the moms what the babies will weigh cause the moms are always more accurate than the u/s. i guessed 7.1 and that's exactly what he was.

[Jo..]

My high risk practice was VERY proud of their track record at estimating birth weights. They said that in the vast majority of cases, they were within 10% of the birth weight.

In my case they were about 5% off...they measured him at 7 pounds 12 oz at 37 weeks, he was born the next day and weighed 7 lbs 5 oz.

[erosenst]

They estimated "at least 8 pounds - likely more". She was 6 lbs 13 oz 2 days before my due date. SO - "not very"!

[HannaAddict]

Third trimester ultrasounds are notoriously worthless for predicting birth weight. The later the ultrasound the more unreliable they are. My OB told me this when we she sent me for a very late U/S with my daughter to check amniotic fluid levels, etc. and to try and get definitive info to help us (husband and I) decide whether to keep waiting to go into labor on my own for a VBAC or schedule a c-section at the due date. Everything was fine, baby just had no intention of coming out anytime soon! The u/s guesstimated my baby girl's weight at 10.5 pounds, but she was exactly 8.5 pounds just a couple of days later! The u/s doctor also made sure we knew that late u/s's are not reliable indicators for weight and that they usually predict larger babies than people actually have. My SIL had the exact same experience, late in term u/s with high weight predicted while trying for VBAC but baby was 2+ pounds less. Her doctor didn't share the fact that the weight predictions are not reliable though! She had to do her own research.

While these examples are just anecdotal, you can do a yahoo or google search and find tons of medline type, peer reviewed papers and studies that say there is no predictive value for late stage u/s for weight. I was surprised at the date myself when I started looking. Good luck.

Kimberly

[DebbieJ]

Ultrasounds are notoriously unreliable for predicting weight.

~ deb
DS born at home 12/03
Breastfeeding After Reduction is possible! www.bfar.org

http://www.bfar.org/members/fora/style_avatars/Ribbons/18months-bfar.jpg

[SnuggleBuggles]

Why do they feel the need to do these evaluations anyway? They aren't accurate. And I really think that if mom goes into birth thinking that baby will be big it can mess with her head. Things going slowly then rather than work on fetal postion or just be patient I'm sure some moms get the CPD (baby too big) c-section. It just seems better to go into it believing that things will be normal rather than have that seed of doubt in everyone's mind. I don't think any organization (ACOG...) even recommends these. No idea why they need to do them- especially for normal, low risk pregnancies.

Just musing...

Beth

[trumansmom]

I was told at 35ish weeks that my DD was already 8 pounds. I was induced at 38 1/2 and she was 6 lbs 15 ounces.

Jeanne
Mom to Truman 11/01 and Eleanor 4/04

[elephantmeg]

I had a friend who had an elective c-section (with a mostly midwife group!) because she was going to be induced because the baby was so big-but wasn't favorable for an iduction-no dilation/effacement. Her baby was 7 1/2 lb!

[aa2mama]

I only had the 20 wk ultrasound, so I didn't have any prediction on the baby's size. My sister, however, had weekly ultrasounds in her 3rd trimester. At 40 wks they predicted the baby was 4lbs. She freaked out and asked them how accurate it was. They said they had top-of-the-line equipment and it was within 2 ozs. They insisted on inducing because they didn't know why the baby was so small. She turned out to be 6lbs 1 oz.

[jess]

Both my my kids were predicted to be 10+ pounds, and c-section, as well as inducing, were discussed. My daughter arrived a few days early at 7 pounds; my son arrived exactly on time at 7.3 pounds. The predictions were done by two different Dr.'s: one was very well respected, the other was head of the high-risk unit. I would never depend on ultrasound to give an accurate reading!

[JoyNChrist]

Predicted 8-9 lbs at 38 weeks. Born at 39 weeks & 5 days weighing 7 lbs, 4 oz.

[MarisaSF]

My ob said the best predictor is Mom's intuition.

I did not want any estimates done as they are not very precise. Also, people were guessing my baby was big and I didn't want to be psyched out of a drug-free delivery.

DS was 10 lbs, 6 oz. IME, big newborns are pretty nice. :)

[smzapalac]

With DD #1, I was supposed to have a 9 or 10 lb. baby. At delivery she was 6 lbs. 11 oz. A teeny, tiny baby compared to 9 or 10 lbs. As a result of the estimate, I didn't purchase any newborn/preemie size clothing because I thought the baby was going to be a lot bigger. Thankfully my mom came to visit and brought some outfits so we could dress our little one.

I am 17 weeks now and am not going to pay any attention to the size estimates this time around ;-)

Good luck to you!

[table4three]

Mine was actually right on - off by only 2 oz. US was done the day before he was born at 35 wk, specifically to check weight/size because I was measuring too small.


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[maestramommy]

I have to say I was stunned by the accuracy of Arwyn's prediction. The peri said she would be 7 lbs 10oz. She was 7 lbs 8 oz.

[pb&j]

Am I the only one here who read the OP's subject line and thought, "it was totally accurate - there was only one baby on the u/s?"


-Ry,
mom to Max the one year old
and my girl in heaven

http://www.windsorpeak.com/dc/user_files/37124.gif

[brittone2]

ITA. I never requested a size estimate. I figured the kid has to come out one way or another, and I didn't need to be psyched out or fearful of a "big" baby (and I carried HUGE out in front with DS so every layperson felt the need to tell me I was having a 10 pound baby).

I didn't have any USs after the 20 weekish one with either baby. Both weighed exactly the same, a pretty average 8lbs 4oz. Both were easy labors, and I'm very small framed. With DS my midwife did decide for some reason while I was in labor to tell me that he felt like he was going to be at least 9lbs...I never asked and didn't want that information, but in the end, it didn't really matter anyway.

I have known several people that were told they were having a "big" baby and were induced before 40 weeks, to give birth to 6 or 7 lb babies. In one case, the baby was induced because mom was "uncomfortable" and the doc was convinced the baby was over 8lbs at 37 weeks. The baby was born weighing barely 6lbs, and had a lot of preemie-type issues, ended up in the NICU, and dealt with several preemie-related problems for her first year of life. She may not have been the full 37 weeks, or she may have just not been ready at 37 weeks.

I'm in the camp that the weight estimates from USs are definitely inaccurate, and in the absence of other complicating factors, personally I wouldn't let it factor into a decision to induce, etc. and I wouldn't worry myself over the number given to me.

[denna]

My u/s was way off as well. They predicted a 9lb+ baby and he was 7lbs even.

I had never heard of predicting a birth weight until reading it on this board and so I asked my OB to predict for me and he said that it would be *way off* and of course it was.

So I would honestly not get too worried. YOu can probably predict much better based on your first DC then w/ the U/S.

Good luck!

[SummerBaby]

Sorry, pregnancy brain- should have said "weight," not rate. :)

Val
DD 2.5 years old
another summer baby coming in 2007!

[SummerBaby]

Thanks for all your experiences. If anything, it sounds like the ultrasounds usually OVERestimate weight. I had the ultrasound to check the growth of a fibroid, and because I have a history of preeclampsia. I would never consent to induction or a c-section because of the size of the baby. My grandmother, who was 5 feet tall and 100 lbs gave birth to two over 10 lb babies. I'm 5'9" and not petite so I am not really fearful of delivering a large baby. I guess I was just hoping I could justify my huge size by saying I'm having a huge baby. :)

Val
DD 2.5 years old
another summer baby coming in 2007!

[clc053103]

Prediction: 7 lbs.

Actual: delivered by emergency c section 8 days early ( I was not in labor and even induction failed, but had preclampsia and low amniotic fluid): 8 lbs 13 oz.

I was told if they waited it out until the due date or after, he would have been a minimum of 10 lbs.

Let's look at the bright side- a 10 lb baby means an immediate 10 lb weight loss!! ;-)

[smilequeen]

My OB wants a size estimate u/s this week. I think maybe she just really likes their new u/s machine. I'd like to see him, so I agreed. But even when scheduling it she's telling me it's not accurate. She can tell by feeling him that he's bigger than average, which is not a surpise as Simon was 8lbs6oz at 39w5d.

I think he's going to be 9 lbs give or take and I was right with Simon. So I'm curious what their guess will be anyway.

[MelissaTC]

I was told that he would weigh mid 8 to 9 lbs. At 12 days overdue, he was 7'10".

[hazel]

Mine was way off. At about 36 weeks they said he measured between 6.5-7.5 lbs. He was born at 40 weeks at almost 8.75 lbs. Much more there than 4 weeks of weight gain could have possibly been.

Late ultrasounds are notoriously inaccurate for weight estimates.