How reliable is fundal height as a measure of baby's size?

[LillianB]

I ask because at my 32 week appointment this morning, I was measuring 28. I've been measuring a little bit under throughout the pregnancy and my midwife says it's probably because I have strong abdominals and am carrying more internally. She said if it still looks low in two weeks, she'll set up an u/s appointment and now I'm worried about low birth weight. The little one had a heart rate between 135-140 and has been very wiggly recently.

Is this a bad sign?

[Family4Christ]

I think that measurements can vary based on how you're carrying. I know one day I can button and zip one thing and the next day, it's 3" from closing. Weird. I would say if you're consistently 4 weeks behind, it *may* signal a problem, but if it's one or two measurements, I wouldn't worry too much.

That said, this baby is measuring smaller than any of my previous. My ds was always 3 weeks ahead and my daughter was about 2-3. This one is a week or so behind
(both in u/s and fundal). So, I worry just based on the fact that she's following a different pattern .

[finnegansmom]

I don't think it's super reliable. I would trust a MW palpating my stomach more than fundal height. If it's measuring behind by a lot, consistently or ahead, it could be sign or excess or not enough amniotic fluid. I know with #1, I was measuring far head and he was only 8#1 and with #2 I was measuring on target or a week or so behind and he was almost 10#.

[nova22]

Ditto to Michelle, I trust the midwife's hands more than the fundal height (but neither is 100% accurate). Baby's position has a lot to do with fundal height, as I learned with #4, who decided to be sidelong breech for most of the third trimester. That threw my measurement WAY off and when he finally turned head-down, there was a drastic difference in my measurements.

[mylilmonkeys]

More indicative than the actual number measurement is the consistency of growth over time. So as long as you are increasing in a consistent pattern, even if it is a little behind, it can still show healthy growth. When growth starts dropping off, or plateauing for a significant period, then there is cause for concern.

[LillianB]

Thank you all. This is reassuring. My midwife didn't seem particularly concerned, but I can't help jumping to conclusions. Thanks for the reality check!

[myk]

ha. not at all. my last u/s said that my baby is measuring 11 days ahead of her actual age (we know the conception, confirmed by first 2 u/s). that was about 2 weeks ago. my fundal height today is 10cm ahead of where it "should" be. i have a lot of amniotic fluid, just like my last pregnancy.. my sister on the other hand was the opposite. she had relatively little amniotic fluid (still normal, but the low end of normal) and a smallish kid - but then she's 5'2 with genetic relatives around the 5'0 mark, so not surprising!

[starbyfar7]

thus far, my midwife has been measuring me based on the whole how many fingers from my belly button the uterus thing is or whatever. at our last appt (yesterday!) we measure at about 18/19 weeks.. and she said for her, the tape is usually pretty accurate once you're big enough to start using it.. but one thing i've learned.. nothing is really across the board 100% all the time correct in anything medical lol. most of the time people are like this, but sometimes they aren't. i wouldn't worry about it

[Kitten]

I measured small for my first pregnancy and got bullied into a late ultrasound, which showed a "small baby" and ended with an unnecessary and painful induction, by hospital midwives. He was 7 lb 2 oz. Second baby, also measured just as small by fundal height. Very experienced HB midwife said 7 lb by palpation. He was 8 lb 7 oz. Lol. I think some women are just good at hiding babies.