Are your children’s vaccines up to date?

Set a reminder

Please or to access all these features

Children's health

Mumsnet doesn't verify the qualifications of users. If you have medical concerns, please consult a healthcare professional.

Tiny babies

24 replies

wishIwasonholiday10 · 13/02/2026 16:52

Has anyone else had a tiny baby consistently below the 0.4 percentile line on the growth chart? My DD was born quite small (5lb13oz at 38w) and then dropped centile until she is mostly following a line below the 0.4 centile line with the occasional dip. I am breastfeeding but have had a lot of pressure to give more formula from heath visitors and we have a referral to paediatrics. She also has reflux and suspected CMPI. Was anyone else’s baby this tiny and perfectly healthy? How worried should I be?

OP posts:
Are your children’s vaccines up to date?
Cat1504 · 13/02/2026 20:54

What have the infant feeding team and the community dietitians said? I would imagine you will have had a referral to both as per your trust pathway for babies under bottom centile

Cat1504 · 13/02/2026 20:55

Guessing you’ve already cut dairy from your diet ?

wishIwasonholiday10 · 13/02/2026 21:03

I’m dairy free already. The dietitian doesn’t think she has CMPI and is probably just small genetically and that the symptoms we had are due to immature digestive system. The feeding team were happy with how she was feeding (no tongue tie but does have a narrow palate) and think we should be giving more formula or breast milk topups but I struggle to get her taking any more due to the reflux (currently trialing Omeprazole for that).

OP posts:
Oldraver · 13/02/2026 21:49

Yep my DS fell off the centiles, he came out of hospital at 5lb ish and was only 15lb at a year old. He had severe vomiting from Reflux and CMPA, but for some reason all the health bods didn't seem to realise that constantly vomiting would lead to little weight gain.

Once when he was in hospital at 5 months after yet another bout of heamatamesis, they insisted on him being fed in front of them as the hinted they thought I wasn't feeding him , and as they do charmingly pointed out, I wasn't exactly skinny myself-- said the doctor busting out of his shirt

So yes they did try to push me to top up/bottle feed. I did point out that it wouldn't stop him vomiting. While I was in hospital I used up my stock of milk I had frozen for the milk bank.

Now even though they didn't use the actual 'failure to thrive' words, I knew that's what they meant. They eventually backed off when they finally admitted he was a thriving healthy (almost) baby. Every scan (heart, brain, kidney, liver etc) never showed issues. Only his stomach/oesophagus showed signs of damage from all the vomiting

They were always perplexed at his size until they knew his Dad was 9 stone

RandomMess · 13/02/2026 22:21

I was going to ask about wider family genetics, some folk need to be on the very small size.

Fizzysticks · 13/02/2026 22:24

My dd was born at 35 weeks weighting 5lbs but then lost a lot of weight overnight and weighed 4lbs. I had to triple feed her in hospital ( breastfeeding, pumping and formula) It was a rough first year with severe reflux but by the 2 year review she had shot up to the 98 centile for weight and off the charts for height and towers above her peers! Honestly it’s now hard to believe she was so small.

Pinkstuffs · 13/02/2026 22:33

My DS was born at 39 weeks weighing 5lb 13oz, he is nearly 2 now and still very slim although he has caught up a bit on height. He was consistently in the 1st centile for weight during his first year. We had regular visits from a health visitor for the first 6 months but after that I think they decided there wasn’t much more they could do with him! He was formula fed though as he was so small he really struggled to latch. He seems healthy and has hit all his milestones in fact he was an early walker and crawler. We also suspected CMPA as he had mucousy stools and eczema but switching formula brands helped this.

I’ve since had another baby who is much bigger which is a strange and different experience! At 7 weeks he is already outgrowing 0-3 months clothes that DS1 didn’t fit into until he was 3 months old!

7238SM · 13/02/2026 22:50

Not me but a cousin. She is 5ft5 and petite and her DH is 6ft 3 and broad. Their daughter was born at term but only 5lbs something! Breast fed but struggled with feeds, cried all the time and was eventually diagnosed with CMPI. She is now 11 and 5ft 7 and can now eat small amount of milk protein.

RampantIvy · 13/02/2026 22:55

DD was 5lb 11oz and was tiny for ages. She is 25 now and is 5'6" snd has a normal BMI.

RSS1618 · 13/02/2026 23:09

My DS was born at 38 weeks and weighed 4lbs 5oz. He was put on a feeding chart so we made the decision that formula feeding was best so we knew how much he was having and could keep track of it accurately.
He will be 3 next month and although very skinny, he’s a delightful, healthy boy

titchy · 13/02/2026 23:13

My tiny 0.4th centile ds is now a slightly chunky Blush 25 year old 5’7’’ - given dh and I are short arses that’s ok. He didn’t increase centiles till he was at school then gradually crept up to the giddy heights of centile 25.

purpleme12 · 13/02/2026 23:16

My child was born at 35 weeks exactly and weighed just under 4 pounds. Tiny.
She stayed tiny. Looked very obviously tiny for a long time. Always in clothes way before her age. But she was growing like she should do so it was fine.
Now she's 12. It's obviously less obvious than when she was younger but she's still below the average height for her age. But not enough so that it stands out I don't think. She's wearing 10-11 clothes.

TheDisillusionedAnarchist · 14/02/2026 00:07

Is she hungry? There’s a really good article here of the signs of a hungry baby. Tense hungry babies tend to finish a feed with arms bent, clenched fists and a frown on their face, whereas well fed babies regardless of growth finish a feed satiated and floppy. https://breastfeeding.support/baby-not-gaining-weight/

No signs of hunger, normal nappies, normal
medical check, normal development can occasionally be normal growth but it’s really worth checking off the list.

Baby Not Gaining Weight

Sometimes a breastfed baby may struggle to gain weight, either not gaining weight at all or not gaining enough weight

https://breastfeeding.support/baby-not-gaining-weight/

wishIwasonholiday10 · 14/02/2026 07:45

TheDisillusionedAnarchist · 14/02/2026 00:07

Is she hungry? There’s a really good article here of the signs of a hungry baby. Tense hungry babies tend to finish a feed with arms bent, clenched fists and a frown on their face, whereas well fed babies regardless of growth finish a feed satiated and floppy. https://breastfeeding.support/baby-not-gaining-weight/

No signs of hunger, normal nappies, normal
medical check, normal development can occasionally be normal growth but it’s really worth checking off the list.

I think she is normally relaxed but I’ll look carefully from now on. I didn’t know about the hands clenched thing.

OP posts:
OtterMummy2024 · 14/02/2026 08:01

@TheDisillusionedAnarchist Those articles are sometimes unhelpful - my baby cried at the end of every feed, but if I relatched them for more milk, they would then vomit because they were actually full! It always made me sad that other women's babies were sated and asleep, and my baby was crying for more despite being full to the brim.

That baby is now a FOMO toddler who cries to keep playing when literally falling over from exhaustion, I think it's just their personality type...

LaVitesse2022 · 14/02/2026 08:21

My DS was born on the 0.2 percentile at just 2kg at 38 weeks. He was completely healthy though and we did formula feed him because midwives were worried at his weight. I also pumped for the first month just so he could some of my breast milk. He started gaining weight very fast and climbing percentiles like crazy. He's now an energetic 2.5 yo on the 75 percentile for weight, though shorter than average (me and dad are also short though).

Dairymilkisminging · 14/02/2026 08:37

I've had 3 small kiddos. All born biggish between 7lb and 8.2oz they all plummeted down to the 2nd centile now they are 16, 8 and 6. Just who they are. No matter what I feed them they are just small and skinny.

Teen eats nothing but crap and shes thin as a rake

wishIwasonholiday10 · 14/02/2026 10:23

wishIwasonholiday10 · 14/02/2026 07:45

I think she is normally relaxed but I’ll look carefully from now on. I didn’t know about the hands clenched thing.

So she appears relaxed (sleepy, not frowning) but her hand is sometimes in a fist. Is that a sign of hunger. Doesn’t feel very tense.

If anything she seems most unhappy if she feeds a lot like when she has taken a bottle as the reflux starts to bother her and she seems to have a sore tummy.

OP posts:
Idontspeakgermansorry · 14/02/2026 10:34

My baby was 6 pounds and zero ounces at 41 weeks. Nothing was ever mentioned to me about her being small or a low percentile. We exclusively breastfed and she caught up, she's a tall but slim 15 month old now.

Some babies are just naturally small.

Superscientist · 14/02/2026 11:05

My sister was 6lb13 at birth and only 7lb12 at 10 weeks and was admitted for refeeding. She was below the 0.4th percentile until 12 months when she reached the 0.4th between 1 and 2 she moved up to the 50th percentile. As an adult she is 5ft4 and slim build.

I was 6lb2 at birth followed the 2nd percentile from birth. As an adult I am 5ft2 and slim build.

My other sister was 7lb8 oz at birth, perfectly average size. When she was 3 and I was 7 we could share clothes. As an adult she is 5ft3 slim build.

Our size as babies young children has not changed our size as adults! We can all share clothes.

We suspect my first sister had a dairy allergy as my mum noted a lot of commonality between her and my daughter who has a lot of allergies and reflux which my sister has too. My sister was randomly sick frequently from being a young child until she went vegan at 40. My mum can't tolerate dairy either.

TheDisillusionedAnarchist · 14/02/2026 20:27

Have you seen an IBCLC. I agree that babies with high supply tend to end feeds fussy too because they want to suck and don’t want milk so they get frustrated.

An IBCLC whether NHS or private could help you pick apart whether she is a baby that actually could do with a bit more milk or is just a healthy small baby. Watching a feed with someone who sees a lot of babies usually helps get to the bottom of what’s going on and either you feel reassured or you’ve got a good plan.

wishIwasonholiday10 · 15/02/2026 02:37

TheDisillusionedAnarchist · 14/02/2026 20:27

Have you seen an IBCLC. I agree that babies with high supply tend to end feeds fussy too because they want to suck and don’t want milk so they get frustrated.

An IBCLC whether NHS or private could help you pick apart whether she is a baby that actually could do with a bit more milk or is just a healthy small baby. Watching a feed with someone who sees a lot of babies usually helps get to the bottom of what’s going on and either you feel reassured or you’ve got a good plan.

I have seen a IBCLC who showed me how to improve the latch but was happy with the feeding and milk supply but that was in the early weeks just before I went dairy free. She falls asleep seamingly happy at the end of feeds. She only becomes unhappy and refluxy if I have to put her down.

OP posts:
EcoCustard · 15/02/2026 05:16

Dc3 was 4lbs13oz, born at 39 weeks-left hospital 4lbs10oz, 0.2 centile. Feeding was always tricky, had a combination of expressed breast milk & formula. As tiny, her suckling reflex wasn’t there, feeding was little & often, & I would have to wake her. She’s 8 now, still feeds little & often & is small (in comparison to siblings), very fit & healthy.
All Dc were tiny babies, all fed & gained, all now taller than most of their peers, slim too, all healthy. Dc one (5lbs) had CMPA but not diagnosed until later, he gained slowly & was a very unhappy baby, sick all the time, he’s very tall now. If baby’s feeding & gaining (albeit slowly) I would focus on that. Admittedly I stopped watching their centile on dc2 (5lbs 2oz) after the first few weeks as all fed, gained etc & I felt health visitor weighing & plotting centile led me to stress & worry (unnecessarily). Not advising to ignore advice, but I felt the understanding of tiny babies was lacking & they ignored me when I asked about CMPA with my very unhappy Dc1.

wishIwasonholiday10 · 16/02/2026 10:16

Thanks all for sharing your experiences.

OP posts:
New posts on this thread. Refresh page