# Fetal weight gain after week 38, u/s & MW estimates



## catccc (Feb 22, 2008)

So... I'm wondering if anyone knows how much a baby will gain in the last couple weeks of pregnancy- 38 to 40 weeks. I've heard 1/2 lb a week and I've heard 1/4 pound a week.

Also, I know u/s estimates are notorious for being waaay off, so I wouldn't put too much stock in this, except that I had 2 midwives independently concur by "feeling" the baby through my belly. The midwives both said about 6 and 1/2 pounds. Then (I won't get into why, it's a long story), they sent me off to the hospital to get an u/s, and the tech estimated the weight at 6 lbs, 8 oz- exactly what both midwives guessed.

Anyone know how close midwives get to the correct weight with the mushing around of the belly to feel the baby? I'd guess an experienced midwife would be much more accurate than an u/s. Just because they are physically feeling the baby, as opposed to looking at it through a machine.

I'm kind of surprised because I was sure I'd have a really little LO. My siblings and I were all born past 40 weeks, and not one of us was over 6 pounds. My mom is a small person, and I am even smaller than her. My weight gain this pregnancy has been just a shade below normal (20 pounds total). And I think a shade below normal is "normal" for me, being 4'11" and 98 lbs pre-preg.

What do you guys think?


----------



## jrabbit (May 10, 2008)

I would trust the mw weight estimate long before an u/s. My last baby was born at 42w5d. She was 8#13. We had an u/s 2 days before she was born, and the IDIOT guessed that she wasn't due for 2 more weeks AND said 7#8 .... It's much more likely that an u/s is going to over-estimate the weight than under, but there is a 2# margin of error.

The estimates of 1/4 - 1/2 pound per week are just that: estimates. Your mother probably gained less weight overall than you have, which explains why you were 6#. So was I, and my mom swears that I was born at 43 weeks.

But, the most important thing I'd like to say is that 6.5# **is** small !!! Even 7# is small! This is the time in your pregnancy when you need to be less concerned about the size of your baby and more concerned about the health of your baby, and YOU. Enjoy. Eat right. Rest. Drink lots of Water. Get a massage and pedicure!

Best wishes!!
--janis


----------



## kohlby (Dec 5, 2005)

My dr says that the average fetal gain is 1/4 to 1/2 a lb a week from 36-42 weeks. As for ultrasound, I found ultrasound to actually be very accurate until after 37 weeks - at which point it was way off. However, my OB's estimate was very accurate at that point.

6.5 lbs at 38 weeks is easily in the average range, likely on the lower side of average.

My OB guessed that DS was 10lb 8oz. The last ultrasound was around 41 weeks and showed a mere 9lbs - however his femur was too long to get an accurate measurement of. He was exactly 10lb 8oz at 42 weeks.

My OB guessed that DD would be somewhere over 10lbs as well - though I never asked her exactly since I didn't want to know her answer - I was pretending that I was growing a little 9-lber. The last ultasound at around 40 weeks showed 8.5lbs. She was born at 41 weeks and 11lb 4oz.

I do think that an experienced OB/midwife can guess as well as an ultrasound machine at the end - if not better. On a side note, I don't know how much maternal size has to do with it. Pre-pg, I'm usually barely 100lbs and I'm 5'1". But the small women in my family have a history of growing huge babies anyways. (Though I blame their lengths of 23" and 23.5" on my tall DH).


----------



## catccc (Feb 22, 2008)

Quote:


Originally Posted by *jrabbit* 
But, the most important thing I'd like to say is that 6.5# **is** small !!! Even 7# is small! This is the time in your pregnancy when you need to be less concerned about the size of your baby and more concerned about the health of your baby, and YOU. Enjoy. Eat right. Rest. Drink lots of Water. Get a massage and pedicure!
--janis

Thanks for the input- I'm not really obsessed with the LOs size, I just play one on TV. I mean, I just sound like it from the post... I didn't know MWs had the magical ability to guess a babe's weight. You should have seen my face when I found out the midwife could tell head v. butt by feel! I love MWs!!!


----------



## Keirasmommy (Jan 17, 2008)

At 36 weeks, my belly measured small and so my MW sent me for an u/s. They came back with my DD being 5 lbs 4 oz. Then 2 weeks later I had another u/s to check on DD's weight gain and they estimated 5lbs 9 oz. Keira was born the next day (induced) and weighed 5 lbs 8 oz, so they were pretty right on with her and I was 38 weeks 5 days. I am also small - 5'2" and 100 lbs pre-pregnancy. With her I gained 35-40 lbs. My mom had a range in size of babies from 6 lbs to 10 (almost 11) with a total of 6 babies in there. So, I think it all depends. They claimed I had intra-uterine growth restriction with DD. I saw a maternal fetal specialist with this pregnancy and she thinks it was where the umbilical cord came out of my placenta causing not enough blood flow towards the end due to pressure from amniotic fluid. But do they really know -no! I'd love to have another small baby, but there is no way to control it!


----------



## JBaxter (May 1, 2005)

between 37 and 38 wks baby gained a pound. I normally I wouldnt hold much stock in the measurements but I could TELL the baby gained alot this is my 4th and the u/s tech kept saying.... these measurements cant be right and remeasuring. I looked at her and said let me guess you are getting 9lb2oz she said... why do you say that... I responeded with he FELLS 9lb+... She said she was getting 9lb5oz







I was close. My OBs are concerned . Im not I knew this was going tobe a 10+baby. I don hope he slows down a bit.


----------



## nuwavemomma (Jul 20, 2006)

My mw was off by 2 pounds. Not a young midwife either.

A pound a week is not unheard of at all, even if your overall weight stalls out the baby is still gaining there at the end.


----------



## DizzyMissLizzy (Jul 1, 2008)

It doesn't just depend on you and your sibling sizes, what about your partner, how big was he?

It also doesn't depend on how big/small you are. I am a little bigger than average and I have very little babies and my step mom who is TINY had all 9# babies...you just can never know.


----------



## mama to 2 girls (Dec 11, 2006)

I believe the later in the pregnancy you get the less they gain, it tapers off, so to speak....

As far as m/w guesses....with dd2 my m/w said she was probably going to be about 8lbs. she was born weighing 7lbs. 12oz. So she was pretty close, she was pretty young. She'd been a m/w for about 5yrs.

With ds both my m/w's (both VERY experienced) swore he was only going to be about 8-8.5lbs. The only person who was right about my ds's size was the student m/w i'd seen 1 time. I told her how much pubic symphasis pain i had been having and she said he feels like he has a big head! I also told her my suspicions that he felt bigger and she said yeah he felt kind of big. He was a little over 10lbs. with a 15" head!







I am not a tiny person but I'm also not huge 5'5" average weight. Also FWIW my u/s with ds at 28 weeks only had him measuring ahead by 2 days.

I don't know if it has so much to do with how long they have been a m/w...I think some people just have better instinct than others. Just like I can pretty much look at something and tell you how long/tall/weight etc. and my dh will look at me like I am crazy, he always has to measure everything. I am usually right. I guess I just have a knack for it.


----------

