Cervix Dilation during Labour and Birth

The tenure of pregnancy is a beautiful episode in the life of the parents-to-be and especially the mother. While giving birth to a new life has its own set of challenges, it is certainly a memorable experience. Giving birth to a child is an intricate process which requires multiple organs of the mother’s body to function in tandem. The cervix is one such important organ that plays a crucial role in the labour and birth process.

What Happens to the Cervix In Pregnancy?

Cervix, most commonly known as the neck of the uterus, is a tube-like structure that is present in between and joins the vagina to the uterus. The narrow opening of the cervix during early pregnancy is closed by thick, gelatinous mucus which is secreted by the cervical glands. This is the first change that the cervix undergoes during pregnancy. It undergoes multiple changes as the pregnancy progresses, especially during the process of labour.

What Happens to the Cervix During Labour?

While it remains closed for the most part of the pregnancy, the cervix softens and elongates as the pregnancy progresses and undergoes significant changes in the last month of labour.

Before the last month of pregnancy, the cervix is around 4 centimetres long. It begins to shorten in the ninth month of pregnancy and moves from the posterior position into the anterior position, pointing forward. The cervix begins to become thinner and gets pulled up into the lower part of the uterus. This process is known as effacing or effacement.

Effacement is calculated in percentages and is an important sign of the body preparing for labour.

The stage of effacement is followed by dilation of the cervix. This is the stage where the cervix opens up to allow the baby’s head to pass through it. The cervix starts dilating during contractions and dilates up to 10 centimetres during delivery. Once the dilation is complete, the baby is pushed out through the cervix.

Cervical Dilation During Birth

Cervical dilation is the stage of labour where the contractions lead to the opening of the cervix which allows the baby to come out. Following are the changes which are experienced by the cervix during the course of pregnancy.

• The cervix remains closed during the initial stages of pregnancy to protect and support the growth of the foetus and uterus of the mother.
• At the time before labour, the cervix moves into anterior position from being posterior to align with the vagina and point forward.
• During the labour, cervix flexes to contractions and intrauterine pressure of the uterus.
• The wall of the cervix becomes thinner during labour, allowing it to achieve effacement.
• As the pregnancy progresses and reaches its end, the cervix begins to ripen. The amniotic fluid content inside the cervix increases during the labour, allowing it to reach vascularity.
• To deal with the contractions, the cervix starts to soften and change colour which allows it to stretch and become thin. This is necessary for the delivery of the baby.
• To allow the head of the baby to pass through, the cervix dilates from 0 to 10 centimetres during labour.
• The dilation of the cervix is measured in percentages. The size of dilation during various stages of labour are as follows:

Latent phase: 0-3 centimetres

Active labour: 4-7 centimetres

Transition: 8-10 centimetres

Full dilation: 10 centimetres. The baby is delivered shortly after the cervix achieves this stage of dilation.

Problems With the Cervix

At the time of labour, certain complications may arise during the dilation of the cervix.

• If the length of the cervix is less than the usual 3 centimetres during labour, it can lead to incompetent cervix and cause complications such as premature delivery.
• Pre-labour contractions cause the cervix to shorten and widen as a normal process. In case the cervix shortens without contractions, it leads to an incompetent cervix which can result in premature labour.
• In case the cervix shortens without contractions, the cervix is stitched surgically to hold it in the closed position. This procedure is known as cervical cerclage and is undertaken only under rare circumstances.
• At times, the opening of the cervix might be tightly shut and does not dilate or open. This is a situation where the woman’s cervix is stenotic. This might happen due to several reasons such as previous surgery, infection or genetic abnormalities in the woman.

In case of any severe problems or complications, the doctor will take the necessary steps to ensure that the process of delivery is not hindered and is as normal as possible.

What are Cervical Tears?

Minor cervical tears during the delivery are not uncommon, especially in case of the birth of the first child. The chance of cervical tears is higher when the delivery is assisted by instruments such as forceps or vacuum. However, such tears can occur even during normal delivery of the child.

Other reasons for cervical tears include precipitate labour, a rigidity of the cervix due to previous surgeries and delivery through a very vascular cervix.

During contractions, the mother might experience severe cervix dilation pain which is not unusual. However, if vaginal bleeding accompanies the pains, it is an indication for the doctors to examine the cervix for tears.

Unless severe, the tears will not require any special surgery or treatment and will heal by itself with time.

Tips to Relax During Labour

Labour is a time where the body is stressed and going through phases of anxiety. The whole process can be tiring, and cervix dilation during pregnancy can take a toll on the mother. It is therefore important to relax, to ensure that the labour is smooth.

Here are tips that will help you relax during labour:

• Stay calm. Tell yourself not to panic during the process. Having a family member beside you will help.
• Meditation and positive thinking will help you to relax and stay calm.
• If the contractions which facilitate the opening of the cervix during pregnancy are too painful, ask for pain relief medication to your doctor.
• Put your body in a position where it feels comfortable. Change positions if necessary.
• Breathe continuously in between the pushes. This will replenish you with oxygen and provide energy to the body.

Your body is designed to bear the pain associated with giving birth and hence it will automatically recover naturally and safely, once the process is complete.

The process of labour is a tiring process, and cervix dilation can be painful. It is best to think about your bundle of joy which is about to come into the world and the happiness the baby will bring into your life. Understanding cervix dilation and being prepared for it mentally will help you pass through the phase with relative ease.

Once the delivery is complete, give yourself sufficient rest and allow the body to recover before you start performing your daily chores again.