I run a big midwifery Facebook group and one of the questions coming up a lot recently is:
‘Is 37 weeks pregnant actually term?’
Follow up questions include:
Is a Mum allowed to use a birth centre if she’s exactly 37 weeks pregnant? What about if she’s one day before that?
Does a baby at 36+6 need extra observations and heel prick blood glucose levels doing? What about if the heel pricks stresses them out and interferes with breastfeeding? Could we just pretend they’re 37 weeks since it’s so close?
How important is this concept of 'term' anyway?
I can easily get stuck on this kind of question. This is my typical thought process:
1. SAFETY! Safety first, I have a responsibility to offer the safest care I can, and who am I to question guidelines, I’m just one fairly junior midwife
2. Lots of excellent midwives I know are fans of cut off points, so there must be good evidence for this
3. But when I look up the evidence or read researcher’s blogs words like ‘low quality’ and ‘weak’ start to pop up...are we making decisions based on culture again?
4. Conversations about due dates, induction of labour, and whether babies born at 37 weeks are more at risk are HARD!
I bet you’ve come across similar problems?
You might know about Dr Sara Wickham, I have a burning desire to lock myself in my room and binge read her blog fairly often. She’s a researcher and independent midwife.
She and other researchers have a lot to say on the topic of due dates and the concept of being 'term'.
For instance, the 280 days of pregnancy we use to estimate the ideal length of pregnancy appears to come from something called Naegele’s rule, which we started using in the 1800s. There’s not much new evidence to back it up.
(Naegele was a German Obstetrician or a ‘dirty old man who names things after himself’ to quote one of my old midwifery lecturers, smashing the patriarchy one physiology lecture at a time...).
Only 4% of babies will arrive on their due date. Also, there’s evidence to suggest that dating scans are only as accurate as last period dates. They're not as precise as we sometimes like to think.
Also, what about genetics, ethnicity and even nutrition? Wouldn’t it be weird if these things had no impact on a woman’s ideal length of pregnancy?
All in all, due dates are questionable.
The other thing is, we’re not really sure what starts labour. It’s a synchronised swim of hormones and physiology. It's not a factory process which notices a finished baby and then ships it at the correct date.
How do we know if a woman’s gone into labour for the correct physiological reasons or if something else has started it? We don’t often have clear answers. One baby could be completely ready at 37 weeks and another might be displaying breathing problems associated with prematurity.
We also don’t know why! Is it because women have varying length pregnancies or because we have due dates wrong?!
What we come back to is:
What even is a full term pregnancy?
I’ve come across some evidence from the American College of Obstetricians and Gynaecologists which suggests that the idea of ‘term’ simply looks at the evidence on how babies get on when they’re born. On average, at 40 weeks, babies have least respiratory and other problems, though anything from 37-40 weeks looks pretty good too.
But newer evidence suggests babies born between 39-41 weeks do ever so slightly better. This means in the USA, 37-38 weeks is now considered ‘early term’.
But these studies aren’t perfect, the concept of a due date is just our best educated guess.
So is 37 weeks actually term?
If we going to go along with the concept of a term pregnancy, most guidelines, including those from the UK, say yes. America has recently renamed 37-38 weeks ‘early term’.
But as with all these things, it’s a line in the sand based on all available evidence.
Mother Nature didn’t leave us with a rule book saying ‘pregnancies will end between 37 and 42 weeks and if this doesn’t happen medical science will need to intervene’. It’s all just on a scale.
Having good observational midwifery skills and knowing the things that babies need like breastfeeding, skin to skin, rooming in with Mum, etc., are all good ways of supporting a baby who may or may not be a little early.
I’ll be making it my mission to to get to know every Mum and baby as an individual (as far as possible in busy practice!), as this is the best way of picking up on issues.
Now I’d love to hear from you:
Have you had experience with babies born around 37 weeks? Any stories you can share to teach us?
Is questioning the evidence and not having absolute answers about due dates outside your comfort zone? If so, what’s one action you can take to better communicate evidence to women?
Hope you found this as interesting to read as I did to write!
All my best, Ellie xx
p.s. Comments welcome, please put in as much detail as possible. You never know, what you add might prompt the breakthrough that another student or midwife needs to support a woman 🙂
I am an experienced midwife & mum of 5. All my babies were born at term or beyond. My last baby was induced at 37 weeks for maternal age ? He behaved completely differently. He was slow to feed, resulting in a 15% weight loss, got jaundice, had to top up & took 6 weeks until he was fully breast feeding & gaining weight. He is now 4 & is still small & has multiple food allergies!?! I am a big supporter of term meaning around 40 weeks as far as IOL is concerned ?
That’s so interesting Bella. I hope his food allergies improve x
Hiya. I’ve had 2 kids, and had gestational diabetes with both. My first was born at 39+1, and was covered in vernix and struggled with low blood sugars. My body had been completely unreceptive to the 2 pessaries at induction so I ended up having lots of syntocinon to get my labour going, and I am utterly convinced he just wasn’t ready to be born yet as we had feeding and bonding issues. My second was born via induction at 37+4 as they had concerns he was small. He turned out to be bigger than my first, and his blood sugars were ok, but again he was covered in vernix and he got severe jaundice within 24 hours (which I hadn’t been told was a high probability at “early term”). In my opinion, both of my boys were born too early, as indicated by the vernix and the issues we had following birth, (and I would have preferred spontaneous labours tbh) but I went by the generic advice I was given. Our outcomes ended up being good so I don’t regret being induced, but I do think that professionals could (and should) be much more honest about the lack of evidence supporting some guidelines, and EDDs in particular, so that parents are able to make a better informed decision. If I had known about Naegles rule before my first birth I might have made very different choices.
Yes, it’s a hard one isn’t it. The discussions about risk and evidence would be longer and more complex but overall it’s the right thing to do x
My baby was born at 39+6. He was born below the 10th centile at 5lb13oz and experienced some breathing difficulties and has bad reflex during his first 3 months. I was induced following my waters breaking spontaneously, sometimes I wonder whether he needed a few more weeks inside, going towards 42 weeks. He is very healthy though! Just a little small ?