Fetal abdominal circumference below average?

[towny06]

Hi, I have just had my 20 week scan and it appears the fetal AC is just below the 5th percentile. All the other measurements (BPD,HC,FL) appear to be fine, but I am going back for a scan in two weeks just to be sure. Does anyone have any experience of this? I know I shouldn't panic but I am a slightly worried...TIA

Hi towny

I've had a similar problem and can sympathise because its really scary to be told something isn't quite right.

My pregnancy was classed as high risk of IUGR from the beginning due to an existing medical problem/medication I have to take so was booked in for growth scans. My 20 week scan measurements were spot on for EDD but by 28 weeks was told the AC was +95 centile - totally the opposite of what I was expecting!!

At 32 weeks, all the measurements were closer to the upper normal range, which I thought was great but then the Dr terrified me by saying this actually indicated a static growth trend and was sent for a doppler scan the next week to check placental function (which was fine) and another growth scan at 34 weeks.

After 6 weeks worrying that at first I had an enormmous baby and then a baby that wasn't thriving and may need a prem CS at 34 weeks, the next 2 measurements have followed a neat trend suggesting that the 28 week measurement was just wrong.

I have another scan at 38 weeks just to be sure but I can't help feeling that all the worry has been for nothing and I have let it ruin the later stages of my pregnancy. Mainly because I made the mistake of searching the internet for answers to what might be wrong rather than going back to the Drs and double checking what was what.

So, please try not to worry about an isolated measurement as IMO it is not an exact science, and the baby's position at time of scan seems to greatly affect the ability of the sonographer to measure acurately.

My best advice is to make sure you ask the Dr loads of questions next time and don't leave the consulting room until you are satisfied witht the answers - and if in any doubt don't be afraid to ask for a 2nd opinion! I wish I had. Google has a lot to answer for!!!

Hope this helps and that it all works out OK for you

Towny, hope my experinece can help. I had this with dd1, from 20 week scan onward really. As ORANGECRUSH says, it really spoilt the pregnancy for me, and for no reason either as it turned out . DD's ac measurements were 5 centile, everything else 50/60th. We were monitored for IUGR, and at 32 weeks scan they said she was off the chart and measuring (ac) 5 weeks behind. They did dopplers etc and all fine. Consultant suggested dd would be very small (less than 5 pounds)though midwives at the hospital took one look at me and said 'that's not a small baby'!. To cut a long story short, I was extremely stressed out to the point of tipping into depression. As it turned out dd1 was born 5 days early (naturally) and weighed 7 pounds 6 ounces . She has always been naturally skinny, and still is age 7. I've had 2 more dds since and sonographer told me then that they are starting to realise babies don't grow in linear progression, everything nicely following the same graph line, all parts growing together, just as babies and toddlers have growth spurts then nothing for weeks.
Please, please don't worry unnecessarily. Ask consultant all the questions you can, but remember that all babies (like people!)grow differently!

and also try and remember that the measurements they are taking are in millimetres - really, really tiny - not like the big size differences you are probably imagining. I had problems after my 20 week scan in my 1st pregnancy (my ds was fine) due to one measurement being off - and going by scans I had at 12 weeks and 16 weeks with this preg - I am fully expecting one of the measurements with this baby to be off (above the 99th centile) at my 20 week scan. Try not to worry - if all other tests and everything else in the scan was fine, I'm sure your baby is okay.

Thanks for posting this. You have just helped me relax about receiving the news of my baby measuring ‘too small’.