Confused: big baby and normal fundal height

sambi1016

This may be totally silly but I just can't get it out of my head. I just had my growth scan this past week at 34w5d and baby is already measuring 6lbs 4oz. The ultrasound tech said that there is definitely a healthy sized baby in here and everything looks good but because of his weight he is measuring at 37w. The next day I had my check up with the doc and she really didn't have anything to say about the weight or measuring ahead and says my fundal height is still measuring on target for my EDD (which is 1/16/14). Then she asked me if I had GD and I said no. I guess I'm just confused as to the link between his size and the fundal height measurement. Anyone have this experience before? Was baby born early or late? TIA (this is my first discussion post - be gentle lol )

forevergraceful

Ultrasounds to measure are best for reference only. I believe they can be off up to a pound in either direction. If your doctor wasn't worried, I wouldn't be worried. 

megs12914

BalletLover said:

Ultrasounds to measure are best for reference only. I believe they can be off up to a pound in either direction. If your doctor wasn't worried, I wouldn't be worried. 

This. I couldn't find a good way to word it like she did!

Siblynika

Ultrasounds aren't an exact science- there's no way they can tell you EXACTLY what your LO will weigh. Fundal height can also measure differently based on how the baby is laying.

sugarland726

Siblynika said:

Ultrasounds aren't an exact science- there's no way they can tell you EXACTLY what your LO will weigh. Fundal height can also measure differently based on how the baby is laying.

Ditto this. A baby lying transverse will measure different than a baby lying in a vertex position. I wouldn't be too worried.

Kc101212

Second to all the above.

My LO is measuring ahead and my fundal height measures behind. My OB isn't concerned, but has sent me for quite a few ultrasounds just to keep better track of LO's growth.

MrsGraham06

It could be several things- the u/s measurements are off for weight, you could have less fluid, baby could be laying a weird way...

There is a wide range of normal at this point, and if your OB isn't worried, I wouldn't be either.

jwp325

BalletLover said:

Ultrasounds to measure are best for reference only. I believe they can be off up to a pound in either direction. If your doctor wasn't worried, I wouldn't be worried. 

This. My SIL was told at her 40 week ultrasound that she was going to have a ten pound baby. My niece was about 6 and a half pounds when she was born four days later. My LO is around 6 pounds based in Monday's ultrasound and my fundal height is on target with me being 36 weeks. LO also is sitting low so that could be part of it.

AnnikaD20

Fundal height is very inexact. Doctors like it cause it's fast and easy and non-invasive and gives some information, even if it's approximate. Your body shape and how you carry can make a difference, and baby's position can have a huge effect. So there's a huge range of normal.

Ultrasound is supposed to be more accurate, but still can be off by quite a bit. They tell you it can be off by up to a pound, but I've heard lots of stories of it being off by as much as two pounds (or 3.5 lbs for PP's SIL !!!)

katags

katiemarie86 said:

My fundal height is measuring small, but LO is measuring in the 60th percentile. My doctor isn't concerned as long as baby continues to grow appropriately. I do know LO is super low, I feel like a hand could come poking out at anytime.

This is me exactly too. The baby's position within your body can impact the fundal height.

BABYROSEJEANS17

My OB won't do any more ultrasounds and while my fundal is measuring on target I always wonder how big DS is going to be.  This is my first and everyone says I'm carrying rather small so you can imagine the anxiety.

RingOfFire11

I wouldn't worry - I think both can be off. My fundal measurement was "textbook" according to my doctor when I was pregnant with DD. He told me he expected her to be a smaller baby just 2 days before I went into labor. She was an ounce shy of 9 lbs at 40wk,2d.

sambi1016

Thanks everybody! I know these things can be off but it's nice to hear the same from others. @BABYROSEJEANS17 everyone has been telling me throughout my pregnancy that I look small too! Imagine my surprise when they told me the little guy was a couple weeks ahead

mrsjenni

I think everyone pretty much covered it.  Take growth ultrasounds with a grain of salt.  They measure the head and belly circumference and the femur length and use those 3 things ONLY to determine the baby's weight.  Clearly this is not an exact science and is just a rough estimate.  

I was told this baby was weighing 6lbs at 32w1d and my belly measured 6 weeks ahead yesterday at 33w1d.  Although baby girl is measuring bigger than my other kids at this point, I'm sure she'll be about the same size as them at birth.  DS1 was 9.5lbs at 38w and DD1/DS2 were both 9.3lbs at 39w.  Really the only way to know is wait until their born

Don't worry too much about it!

KatelynEA90

I had an 'on-target' size baby but measured 5-6 weeks behind by fundal height. Baby was born on time.