Baby in 6th centile at 35 wks but no cause found - should I be worried?

[mg707]

At my growth scan I was told that baby (no.1) is in the 6th centile, down from 11th centile at the 20 week scan. My placenta flow and fluid around the baby all look good, but the measurements show that baby's head has grown a lot relative to the tummy. Apparently if the head grows more than the tummy it may suggest a placenta problem, but my placenta readings look normal. I'm getting myself all worked up about how small baby is, whether the measurements are accurate, whether it's anything I've done etc. I'm a non-smoker, never drank, never used drugs, no blood pressure problems or diabetes etc. Pregnancy has been completely fine so far. Has anyone else experienced the same panic about a very small baby? Is it worth getting my placenta re-checked or maybe clarifying some of the numbers?

In my experience, scans aren’t great at predicting gestational size.

My little one was estimated 7th centile at 38 weeks … he was induced because they thought he was ‘small for dates’. He came out 5lb15oz which is close to the 15th centile I think. My little mini but no problems at all ☺️. I was a small baby (5lb11oz) so not hugely unexpected I guess!

Sorry you are going through this worry. I had similar, at 37 weeks fundal height measured a little less than expected so was referred for growth scan and that showed baby has dropped from 10th centile (20 week scan) to 7th centile. Placenta and blood flow all looked normal. They booked me in for an induction at 38 +5 and told me to closely monitor movement in the meantime. It was a stressful time and I asked to have a consultation with the midwife consultant and the obstetrician which helped to discuss in more depth. Since you are 35 weeks maybe you could get the numbers checked or maybe ask for another scan on the placental function and definitely ask to speak to the dr / midwife again. It’s likely they will book you in for induction - did they discuss this with you?

if it helps, my baby was born healthy but small (2.4kg) after the induction, and has since been thriving.

I hope you’re ok, it’s so stressful and a shock to have to deal with this late on in pregnancy.

My son was flagged as small at around 25 weeks and we had all sorts of tests done which didnt show anything but we were still told that there may well be problems that only become apparent after birth. We had so much worry for so many weeks. He was in 4th centile until around week 39 when he jumped up to 11th and I was told that we were outside of the danger zone. He was born skinny and long and hes stayed that way. One of the doctors even said to me that the centiles are based on statistics and someone has to be at the bottom, it doesnt necessarily mean anything and babies come in all shapes and sizes you may just have a small child.
Looking back I wish I hadnt gone through all the tests and additional scans. Obviously at the time I wanted to know as much as possible but it was a lot of stress and in some cases risk that turned out to be for nothing.

Thank you very much indeed, everyone. I'm sorry to hear we've all been through the same stress but thankful for you sharing your experiences. I'm going to recheck the numbers with midwife / Dr tomorrow. They haven't mentioned induction so I'll hold tight until the next scan and take it from there. Glad to hear your little ones are all doing well now!

My twins were in the 2nd centipede. The had IUGR and I had to deliver them at 36 weeks but they were perfectly healthy, just very skinny and tiny.

Op definitely ask for re scan and 2nd 3rd opinion if needed until you are happy. I had IUGR with both my babies. 1st one I was rushed in with pre eclampsia at 38 weeks and 2nd time I demanded induction when they found IUGR again and baby delivered 38 weeks but I had daily monitoring from 37 weeks when it was found.
I would ask about PE bloods which looks at the function of your placenta and will flag up any issues that could arise in the next 7 days. I had them from 32 weeks on a weekly basis with my 2nd baby and all fine but helped me not to stress.

Thanks @abbs1 and @Darthwazette . Just to clarify, did they find a cause for the IUGR (except for the time you had pre-eclampsia)? Or is it just a matter of precaution to induce all small babies regardless of the cause? The doctors didn't discuss induction with me and I'm wondering if that's because my placenta is okay, or whether everyone with small babies eventually gets offered induction.

@mg707 I’m sure that hospitals will have different policies but my experience of induction was that they wouldn’t induce just because baby appeared to be small but it’s to do with whether weight is sustaining and particularly to do with their estimate of abdominal circumference as this is what they use to gauge whether or not baby is getting enough nutrients. This is why they will often do a few scans a week or so apart if they have no other concerns.

In hindsight I would have pushed back against induction as I don’t think it was necessary (you can request increased monitoring instead). However, my induction experience was very positive and quick so if it does come down to that for you then I have only good vibes there. 💛

With my first the IUGR was due to pre eclampsia but as it came on so suddenly they didn't realise until after baby was born. Weighed 5lbs 8oz. He's the most energetic little boy now. Nearly 3yrs old and healthy. With my 2nd they were worried pre eclampsia would come again so when they picked up the IUGR again they said get baby out at 38 weeks as the risk of pre eclampsia from 38-40 weeks goes up the closer you get to 40weeks and they didn't want to risk it again. Baby was 6lbs 7oz so did really well. She's nearly 10 months now and a right little chubby one.

Normally from what I've been told if they find baby has stopped growing or falling on growth charts they will offer induction but definitely check and clarify. With my 1st I begged for induction or c section as I was so stressed and told no and had pre eclampsia so with my 2nd I didn't take no for an answer and got 3rd opinion in the end from a senior consultant who said straight away after seeing my scan and booked the induction for me.

My best advice is do not leave until you're questions are answered. Ask things as many times as you need to. Don't feel stupid. You know your body and baby more than anyone. Even if you go in for monitoring everyday. Do not leave if your not comfortable. Keep a close eye on movement. Both mine movement reduced so I went in every other day for monitoring for reassurance. Sending hugs 🫂

A cause for IUGR is a low Papp-a. (<0.5 mom). This blood test shows the function of the placenta.

How was your Papp-a at the combined test at 12-14 weeks?

A low Papp-a also gives risks of preeclampsia, preterm birth and stillbirth.

I had this, and the placental flow etc all looked good at scan, the placenta looked good when birthed too. But still my baby was born at 2nd percentile by induction, after the IUGR became no growth at all. She was well otherwise and put on weight and gained percentiles after.

Watch baby’s movements and have another scan in 2 weeks to check growth.

We were told our baby was on the 50th percentile at the scans but she came out on the 2nd! tiny but in proportion, so not long and skinny just all round small.

Do you have small family genes? DH's family are all tiny and Asian which I think was the cause.

Btw if your Papp-a was under 0.5 mom they should have put you on 150mg aspirin from 12 weeks onwards to prevent or help with the IUGR. It improves the function of the placenta.

with my first pregnancy, they moved too slow and I only got it from 16 weeks, and only after I brought the low Papp-a into discussion, and they gave me only 75mg.

Second time now (different hospital), they said the correct dose is 150mg from 12 weeks. Best to start it then, and no later than 16 weeks, otherwise it might not make a difference.