36 weeks and 2 days: baby measuring 19th%

[SteelerMom]

At my 34 week appointment (34 weeks and 3 days), fundal height was 32cm so I had an ultrasound today at 36 weeks and 2 days. They measured the head and abdomen and femur then averaged them telling me the baby was in the 19th percentile and may be around 7 pounds if I go 40 weeks. I know these are estimates (they told me my first baby was probably going to be small and he was 8lb 3oz) but I can't help but be concerned since this is so different from my other two babies. (My second son was 9 lb 2 oz.) The funny thing is the head and abdomen were measuring like 33 weeks and the femur length brought her into the 19th percentile by being like 37 weeks. The doctor said he wasn't going to be concerned as long as fetal movement was adequate. I really don't want to obsess over it especially with another probable 4 weeks to go. Also, he said that since this doesn't fit with the history of my other two, my placenta may not be "feeding the baby as well." What does that even mean? Anyone have any similar experience?

[cjarvis]

Hi,
I have 4 children with number 5 due in a bit too. I have to comment because my #3 child was small. He was born at 39wks at 6lbs 4oz. And you know what, he still is small, just the way he is. My 4th child is a chunker and #3 and #4 are almost the same weight and they are 23months apart. So, I hoping you don't have to worry too much and it's just the genes of this baby I didn't have extra ultrasounds, so I can't answer the specifics of that.

[RedOakMomma]

The genetics and specifics of each child can really throw those percentages and estimates out of whack. For example, big heads run in our family. BIG heads. My first pregnancy, twins, we had a 3rd trimester weight estimate done by a very high-tech instrument and a perinatologist.

Because of their big heads, and the way the estimates are done based a *few* key measurements, their weight estimates were HUGELY off. Like, well over a pound. I had the babies just a few days later and they were much lighter/longer than had been predicted.

If your fluid is right where it should be, and movement is normal, I'd guess that this baby is just a little different in body shape than your other kids.

[babymango]

A friend of mine has 4 kids. Two were small (barely 7 pounds) and two were big (a good 9 pound each). All four were healthy. It seems she makes two types of babies, skinny long ones, and average length really fat ones. She jokes all the time about having two baby molds.

[MaerynPearl]

my mom had 5 kids ranging from over 9 to just over 5 lbs... (I was 9lbs on the money and born on my due date!)

none of us had any more problems than any other except the one who was about average weight, and his problems had nothing to do with birth weight but rather that he had appendicitis at a very young age and kidney stones starting as a teenager.

[AmyKT]

Just another anecdote....My friend has two sons: the first has always in the 90th percentiles and the second hovers around the 3rd percentile! Both are perfectly healthy, and both have the same biological father (sperm donor). My friend is 5'2" and the biological father is over 6ft, so one obviously took after him while the second took after her in size. Are you and your partner very disparate in size?

Also, I noticed on my ultrasound reports that different body parts were measuring at different weeks. I think the head and abdomen were large (yay for my cervix ) while the femur was smaller. That matches my DD1 and my DH who both have big heads and broad shoulders but short legs.

[MaerynPearl]

Originally Posted by AmyKT

Also, I noticed on my ultrasound reports that different body parts were measuring at different weeks. I think the head and abdomen were large (yay for my cervix ) while the femur was smaller. That matches my DD1 and my DH who both have big heads and broad shoulders but short legs.

DD1 was tall and skinny, they thought she was going to be HUGE because she was so long but no, she was tall but in premie clothes the first couple weeks because she was so skinny (now, at 5... she is tall and skinny! people think she is her 7 year old brothers twin!)

DS was tall and not quite so skinny... they thought he was going to be well over 8 lbs because of his measurements the day he was born but he was barely 7 1/2!

This little one is measuring all over for body parts too... big head like her brother and sister (luckily that didnt mean much for me during labor, I delivered the other two quite quickly without much pain or tearing!) but unlike them, shorter legs and arms, but she has a different bio-dad and he was short until his senior year (really some of his high school pics I would never guess were high school! now, hes around 5ft9in!)

[SteelerMom]

Thanks for the reassurance ladies!

[WifeofAnt]

19th doesn't sound too bad. Somebody has to be in it! Of course I come from the family who was accused of starving us through school. We genetically get really tall and really skinny... except me, I was allergic to all formulas and didn't grow very tall. I'm the only one in the family under 5'6" (I'm the size of a normal 10 year old in my family) but every male is over 6 foot. My 19 year old brother is already 6'3" and in a size 15 shoe and he's still growing!

My (step)mom got so sick of being accused of starving us that by the time my younger brother was 12 she invited CPS over for dinner. Trust me, we never went hungry, we just don't grow outwards until our twenties.

Sorry for that huge reply but the point is everyone grows differently. Just because you're small or 'too skinny' for your height doesn't mean something is wrong.

(I really do hope our son takes after his dad... I don't need more people making me look short.)

[hollytheteacher]

That far along in a pregnancy, i'd take their "measurements" with a grain of salt.

Literally a week before ds was born, they told me he was 5 lbs. He came out a hair under 9 pounds. sooooo he either gained four pounds in ONE week, or they were a tad off!! lol

[HeatherB]

If all other indications are good, I wouldn't be worried about u/s measurements, especially at that time. They are notoriously inaccurate, particularly late in pregnancy.

Also, remember that "average" is 50th-%ile, so 19th is lower but not off the charts lower. It may well mean a smaller child IF it's even accurate. Could be baby's getting ready for a growth spurt and just needs time to catch up. At any rate, I'd hesitate to have u/s late in pregnancy unless there's a known problem. If baby seems to be doing well, and your gut instinct is that all is fine, then I'd not be concerned at all.

[somegirl99]

I'm at 38 weeks and 2 days, ultrasound yesterday put mine at about 15th percentile. Oh, and my fundal height is 33 cm.