The cervix of an expectant mother dilates to different degrees when she is in labour. It is the phenomenon that is responsible for allowing the baby’s head to come out.
Here is what you need to know about cervical dilation:
Latent phase or early labour
During the early phase of labour, your cervix will thin out (efface) and dilate from 0 – 4 cm. That’s about the width of a banana. It is commonly the longest phase of labour. And may occur over days or even weeks in the lead up to the big day.
You may or may not feel contractions at the beginning of this phase. If you do, they are likely to be annoying but not overly painful. Distract yourself with your usual routine. And remember to rest between them.
As the phase continues, the contractions become mild to moderate and last between 30 and 45 seconds each.
During this stage, you may also:
- notice a bloody show might come out of her vagina. This is a viscous bloody vaginal discharge that will come out when the cervix starts to open. It may discharge as one blob, or be streaky in the mucus.
- experience other symptoms, such as a backache and diarrhoea.
This phase is when things kick into gear a bit. Remember it’s not going to last long about two to three or four hours. And anything is doable short term!
During this phase, your contractions grow in intensity and become more painful as your body starts to prepare for the real event. As each hour of contractions ends, your cervix will begin to dilate faster until it has reached up to 8 centimetres. About the size of a doughnut.
Since the baby is moving and settling down in the lower pelvic area, it will exert pressure on your pelvis.
By the time you are 8 cm, you will know you’re in active labour. It is common for women to internalise and inwardly focus during a contraction. Contractions will last about 40 to 60 seconds and are regularly spaced.
Each contraction will start low, build to a peak before falling away again.
Okay, so the baby still can’t fit through the cervix yet. This phase is you sprint home. Well, it’s not really a sprint. Your body has been basically competing in a marathon. But you can see the finish line from here. And it happens quick, one to two hours.
During the transition phase, your cervix will dilate from 7-8 cm and so on until 10 cm. About the size of a bagel. Transition is the most intense phase of labour and is the point when most women doubt their abilities. If you are talking to your future self, remember to say… You can do this! You are doing this!
The intensity of the contractions pick up and last between 60 and 90 seconds each. Again they will have peaks – so you just need to breathe your way through each of those. There will be little downtime between each contraction.
Creation of a passage for the baby’s head
Normally, a woman’s cervix will be firm. It guards the uterus by remaining pointed in the direction of the vaginal wall. However, during labour, the body naturally creates a passage for the baby’s head to come through.
When the long, thick, and 1-2 inches long cervix starts to decrease its size and girth, the process is called effacement. Increased effacement will lead to the cervix being pulled up into the bottom end of the uterus. Simultaneous dilation of the cervix softens and opens it up. The opening becomes wide enough to form a passage through which the baby’s head can leave through the uterus and enter the vaginal canal.
But it’s not all about the mother’s body. The baby also has an incredible role to play. Baby’s skulls have extra bones than its mothers. The baby’s fontanelle is not fused, meaning the bones can cross over each other as it passes through the cervix, down the birth canal and out the vagina. They will then fuse entirely in the first two years of life.
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