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 🙂