Baby size <5th centine at 20 week scan

[Maddiepennie]

Hi,

I had my 20 week scan on Friday of last week and was referred to a specialist Wednesday of this week as my baby's femur length was a day behind where it should be at this stage of my pregnancy.

After seeing the specialist on Wednesday he assured me that my baby's bones were bright, straight and looked healthy, however all the long bone measurements were just coming in short.

Now, I myself am only 5ft1 and pre pregnancy weighed less that 8 stone and my partner isn't exactly big in build or height either. So I feel that I was never destined to have a big baby, more than likely a smaller than average one however I am still really worried. Also, we had our downs test at 12 weeks and the results came in very low risk.

I have another appointment in 5 weeks to check the growth rate so I am being monitored however I wanted to know if anyone else had had a similar experience and what the outcome was?

I wouldn't worry about it. The thing about the centiles is that someone has to be at the extremes as that's the nature of the maths! I had the opposite with DD, she measured 95th centile for length and 99th (!) for her head. The sonographers helpfully kept just saying "don't worry, you're just going to have a REALLY BIG" baby!" Terrifying words to me as a first timer. In fact DD was born at 38 weeks by EMCS and was 12th centile. So all that worrying for nothing! She's now about 75th at 2.5 so it varies.

As you and your DH are not big people I would especially not worry about it. I think everything being in proportion is probably a better thing to concentrate on.

If you are 5ft 1 then your bones are probably 5th centile too, so I wouldn't worry. Good you get a check on 5 weeks time to put your mind at rest.

Mine is 5th centile so getting monitored too. I'm 5'3 and was about 8st. I was a small baby myself so hoping all will be ok. Still getting some good movement.

I think they just use 5th centile as a cut of point to start investigating iugr.

My dd2 was under 5th centile (later realised it was a chromosomal disorder) but then I am 5'4" and dh is 6'4", dd1 was 8lbs6 at birth so we weren't expecting a small baby. It was the centile measurement that raised concerns at first.

If you and your dh are smaller then it's not surprising baby is too. Someone has to be on the 5th. I imagine you referral will be to rule out iugr, once that's been ruled out they'll not be worried.

My DS measured small, in fact I was induced at 40 weeks as they were concerned about his size. He was 7lb 2 oz and yes he was in tiny baby clothes for a few weeks but he's average now for his age and there is nothing wrong with him. Baby no 2 has measured small at 20 weeks but I've come to think that it's not an exact science and if they've changed your dates etc you may be out of sync anyway. They brought me forward 10 days with DS. So I think I had him at 38+5 instead of 40 weeks. Try not to worry and enjoy the extra scans and getting to see your baby more often.

Seriously dont worry! Pregnancy is guess work, the sonographer is measuring accuratley but your babies size is based on the average, therefore it is completely normal for some babies to be under or over the norm.mthe only time there is actual concern is if the growth doesnt go up, but stays static between scans.

Im not sure exactly how much differenc there would be in a day of growth though?

Don't worry. They will scan you more regularly to check baby keeps growing along that centile, but 5% of completely normal babies will be smaller than yours, and if you are small makes sense your baby is too. I had this with my DS2, born full term 6lb 8oz, and my DD, 3 weeks early (spontaneously early, not induced) 5lb 9oz. They are both still following 2nd-9th centile lines but are fine.