Can Paracetamol Slow Down Early Labour? The Rumour, the Research, and the Real Story

If you’ve ever called triage in early labour, you probably know what comes next.

“Take some paracetamol and see how you go.”

It’s become such a predictable script that it’s almost funny- until you’re the one in early labour, cramping and waiting, wondering whether this humble painkiller is doing anything at all.

But in recent years, a new worry has started bubbling up – could paracetamol actually slow labour down? Is it doing more harm than good?

Let’s get into the facts, the theory, and where this rumour really came from.

🕵️‍♀️ Where Did the Rumour Start?

This theory picked up steam after a blog post in 2015 by The Undercover Midwife, who shared an observation that people with longer early labours often mentioned having taken paracetamol.

That sounds suspicious, right?

But here’s the key point: correlation is not causation. If you’re in a long early labour, you’re more likely to reach for paracetamol. It doesn’t mean the paracetamol caused the labour to be long.

It’s like saying umbrellas cause rain because you see them whenever it’s wet out.

So while the blog may have sparked concern, it was based on personal experience and not scientific evidence.

🧪 What Does the Science Say?

Let’s start with what we know for sure:

• Paracetamol is a safe, commonly used pain reliever in pregnancy.

• It works centrally (in the brain), dampening pain perception.

• It does not appear to affect uterine contractions, cervical ripening, or oxytocin levels all crucial for labour progress.

Studies on paracetamol in labour are limited, but the evidence we do have suggests that it does not interfere with the hormonal cascade of labour. It doesn’t delay it, block it, or suppress it.

So while it might feel useless to some (and honestly, it often is in terms of pain relief), there’s no scientific basis to say it slows labour down.

🧬 But Doesn’t Paracetamol Affect Prostaglandins?

Yes, sort of, but this is where it gets nerdy and nuanced.

Paracetamol is believed to weakly inhibit prostaglandin production by acting on COX enzymes. Prostaglandins are important in labour because they help soften the cervix and stimulate contractions.

But here’s the key:

• Paracetamol’s prostaglandin effects are mostly in the brain, not in peripheral tissues like the uterus.

• There’s no evidence that paracetamol reduces prostaglandins in the uterus in any meaningful way.

So while it’s technically true that it can influence prostaglandins, it doesn’t seem to touch the ones driving labour.

🤷‍♀️ So… Is It Useless Then?

Not necessarily.

Paracetamol can take the edge off cramping or backache in early labour. For some, it makes it easier to rest, nap, or simply feel less overwhelmed.

And rest is golden in early labour. If taking paracetamol allows you to get a bit of sleep before the real intensity kicks in, that’s a win.

But if it doesn’t do much? You’re not imagining it. For many people, early labour pain is more mechanical than inflammatory meaning a painkiller might not hit the spot.

❌ What Paracetamol Doesn’t Do

Let’s bust a few myths:

• It doesn’t slow down contractions.

• It doesn’t interfere with oxytocin.

• It doesn’t stop labour from progressing.

• It doesn’t affect your baby. (When taken in normal doses.)

It’s not an oxytocin blocker or a labour-halting villain. It’s just a mild analgesic that might help you feel a bit more comfortable.

🧠 The Real Problem

It’s not paracetamol that’s the problem, it’s the one-size-fits-all approach to early labour.

When someone calls in, describing contractions and uncertainty, being told to “just take paracetamol” can feel dismissive. Especially if you were hoping for reassurance, a check, or some hands-on support.

But here’s the truth:
If your early labour feels slow, stop-start, or just drags on…. paracetamol isn’t to blame.

💡 The real reason?

Positioning.
More often than not, a long or stuttering early labour is linked to baby’s position. Particularly when they’re back-to-back (occiput posterior). This can cause contractions to be irregular, painful in the back, and less effective at progressing labour.

So what helps?
Biomechanics. Movement. Releasing tension.
Understanding how your baby navigates the pelvis and how you can support that process is a game-changer. And no, that doesn’t come in a box of paracetamol.

✅ The Takeaway

• Paracetamol does not slow down labour.

• It doesn’t significantly affect the hormones that drive birth.

• The idea that it causes long early labours is a misinterpretation of correlation.

• If your labour is long, a back-to-back baby is a far more likely reason and biomechanics is your best tool.

So if you’re offered paracetamol in early labour… take it if you want to. Skip it if you don’t. But don’t stress about it either way. Your body still knows what to do.

And if you want tools that go beyond the standard advice… strategies to stay calm, use your body wisely, and support optimal positioning – check out my midwife-led online hypnobirthing course. Because you deserve better than “just take paracetamol”  you deserve real understanding, real tools, and real support.