Most pregnant women will spend time wondering how long their labour will be.
Reading about the stages of labour and the expected time frame is likely to raise some questions.
You might wonder: how long does it take to dilate from 4cm to 10cm?
Early labour (0-4cm dilated) is often quite irregular, with relatively slow progress.
Active labour (4-10cm dilated) tends to be more predictable, with steadier progress.
The length of labour is usually calculated from the start of active labour until the time the cervix is fully open, or 10cm dilated.
Let’s take a closer look: how long does it take to dilate from 4cm to 10cm during labour?
This has to be one of the most difficult questions to answer when it comes to labour and birth.
It’s impossible to determine exactly how long labour will last, as every woman’s experience will be unique to her.
As one BellyBelly fan explains, ‘Everyone is different and dilates at a different rate’.
How fast do you dilate after 4cm?
Realistically, how long does it take to dilate from 4cm to 10cm?
According to the UK’s NICE guidance, active labour with a first baby is likely to last from 8-12 hours, and is unlikely to last more than 18 hours.
With a second or subsequent baby, active labour is often quicker – around 5 hours – and unlikely to last more than 12 hours.
There will always be labours that are much shorter, and of course, some will last much longer.
It’s not easy to define the average length of labour.
Factors influencing length of labour
Any number of factors can influence the progression of labour:
- First baby – first labours are generally longer
- History – if you’ve had a quick labour before, you’re more likely to have a quick labour again
- Gestation – preterm labours are often faster
- Pain relief – epidurals can make labour longer
- Position of baby – the direction your baby is facing makes a difference
- Maternal position – certain positions make for a more efficient labour and birth
- Interventions – they can either speed up or slow the progression of labour
- Pattern of contractions – the strength and timing of contractions are important
- Giving birth to multiples – this can add a twist to the length of labour
- Birth environment – your labour progresses more efficiently when you’re relaxed. This is greatly influenced by your birth environment.
- Being calm and relaxed in labour enables the level of oxytocin (the hormone responsible for contractions) to rise.
- Feeling private, safe, unobserved and supported in labour will also create optimal levels of oxytocin.
As you can see, there’s a wide range of answers to the question: how long does it take to dilate from 4cm to 10cm?
Some or all of those factors might change during labour; this also makes a difference.
The beginning of labour is also called the latent phase or early labour.
During this time the cervix begins to soften and thin (efface). Mild contractions will open the cervix from 0-4cm in preparation for the birth of your baby.
The cervix is the opening or ‘neck’ of the uterus, and it sits between the uterus and the vagina.
During pregnancy the cervix is long and firm, like a tube, and remains closed, to protect your baby.
As your body prepares for labour, a number of important changes take place in the cervix, to enable your baby to be born.
The cervix goes through a process known as effacement. It changes from a long firm tube and becomes shorter and softer.
This process has to happen before the cervix can begin to dilate further.
As the cervix begins to efface you might lose your mucus plug. This is the name for the protective clear or white, jelly-like mucus that ordinarily seals the cervix during pregnancy, to prevent infection.
You might also hear this referred to as ‘the show’.
The latent phase of labour is often the most unpredictable. During this phase, contractions can stop and start, or be irregular in their pattern.
They can also change, depending on your activity, or what position you are in. For example, there might be fewer when you lie down, and more when you walk around.
For some women, the latent phase can last a number of hours; it can even last up to 24 hours or more.
For women who’ve birthed before, some of the changes to the cervix go unnoticed or happen without labour contractions.
They can happen in the weeks and days leading up to labour.
The latent phase can feel frustrating if it goes on for a long time, or stops and starts. Try not to feel too disheartened, even if it feels like progress is slow.
Your body is going through really amazing positive changes, and it’s doing everything it should.
Is 4cm dilated active labour?
Once the cervix has opened to 4cm you are said to be inactive (also known as established) labour.
Most women notice a change in the frequency, strength and duration of their contractions. They will be more regular, more intense and start to last a little longer.
So how long does it take to dilate from 4cm to 10cm in this stage of labour?
Progress through this phase tends to be more predictable, and feels more like you are really ‘in the game’. Although dilation up to 6cm can still be quite slow, progression from 6cm to 10cm tends to accelerate.
Signs of active labour:
- Contractions are 3-4 minutes apart
- They last 60 seconds or more
- They are consistent, despite your position or activity
- You are unable to talk through them
- Focused attention is required to breathe through them
- There’s a ‘bloody’ show.
How many centimetres do you dilate an hour?
Until relatively recently, the definition of the length of ‘normal labour’ was based on a study published in the 1950s by physician Dr Emanuel Friedman.
Friedman’s study was based on his observations of 500 first-time mums and described the average amount of time it took them to dilate per centimetre in labour.
He plotted his results on a graph which then became known as ‘Friedman’s Curve’.
Until the early 2010s, Friedman’s Curve was still used traditionally by doctors and midwives to define a ‘normal’ length of labour.
However, more recent research indicates the findings of Friedman’s study are no longer relevant in modern maternity care.
Many labour practices have changed since then and therefore it should no longer be used.
Researchers found, on average, cervical dilation was not rapid from 3cm, as Friedman’s Curve once suggested.
For all women (first-time mothers and those who had given birth before), progression was only rapid after reaching 6cm.
The average time it took to dilate one centimetre in active labour (from 6cm) was half an hour (faster for experienced mothers). 95% of women took less than 2 hours to dilate one centimetre during active labour.
Most hospitals and health care providers have now updated guidelines to acknowledge these new findings.
Most, however, have not changed their definition of active labour as beginning at 6cm, and so it still stands at the traditional 4cm.
How long does it take to give birth after 5cm dilated?
It’s important to remember that although labour and birth are often discussed in terms of stages, with much attention placed on ‘the numbers’, our bodies are not machines.
It isn’t always easy to categorise each phase.
A number of different factors can influence your progress, such as birth setting or environment, and whether or not you feel safe and supported.
These factors will change throughout your labour and will be different with each baby.
Click here to read more about undisturbed labour.
How long does it take to dilate from 4cm to 10cm?
The process of labour is part of a greater continuum; this makes it difficult to make comparisons, and it’s often difficult to determine exactly where you fall at any particular moment.
Labour isn’t the time to be wondering: how long does it take to dilate from 4cm to 10cm?
Instead, focus on the amazing job your body is doing.
Try not to get too caught up in the numbers and trust your body. It knows what it is doing.
Everyone’s experience will be different, and your journey with your baby will be your own.