Dilation of the cervix is a key step in preparation for childbirth. The cervix opens gradually until full dilation, which allows the child to descend and be born. Steps, measurement, contractions, duration… Lighting with Marie Choquel, midwife.
There dilation of the cervix occurs close to childbirth. Thanks to the force of the uterine contractions, the cervix will then dilate open gradually, up to 10 centimeters maximum. We then speak of full dilation, thus allowing the passage of the baby at the time of birth. The opening of the cervix can take several hours before the baby comes out and is born vaginally. Marie Choquel, midwife, tells us more about this stage of childbirth.
What is cervical dilation in pregnant women?
“The cervix is like a pipe that closes the entrance to the uterus. It is a prominence that can be circled with your finger. During pregnancy, it is closed and in principle does not open until the moment of childbirth“, explains Marie Choquel, midwife. assess the opening of the cervixthe healthcare professional performs a vaginal examination.
During pregnancy, the cervix is completely closed. It may, however, begin to soften and change during the third trimester of pregnancy as it nears term. “Vaginal examination is no longer systematic during pregnancy follow-up appointments. If the mother-to-be feels contractions, we will then examine the cervix to make sure that they have not had an effect on it”, adds the specialist.
Contractions and dilation of the cervix
It is the uterine contractions that will lead to the opening and then to the dilation of the cervix. “If there is no contraction, there is no dilation of the cervix!“, insists Marie Choquel. The mother-to-be will then feel contractions and sometimes discomfort in her cervix.
“Without contraction, there is no dilation of the cervix!”
Dilation of the cervix with 1 or 2 fingers, how to measure?
Rather than talking about centimeters, we often hear aboutopening “with one or two fingers”. “This is a common confusion”, remarks the midwife. “We can speak of a one-finger opening at the very beginning of labor. But a finger does not necessarily correspond to a centimeter and above all, it depends a lot on the examiner!“, she adds.
What are the stages of cervical dilation?
Dilation of the cervix takes place by three stages (three phases) marked with measures :
Lag phase
It corresponds to the beginning of the dilation of the cervix. “When a woman arrives at the maternity ward, after at least two hours of regular contractions that are gaining in intensity, her cervix is usually 2 to 3 cm dilated. But this obviously remains very variable from one woman to another.“, observes the midwife.
active stage
THE collar opens up to 4-5 cm. An epidural can be performed if the pregnant woman wishes and if labor is progressing well.
The transition phase
The dilation is complete, the cervix is open to 10 cm, it is said to be “erased”. “We no longer feel the cervix, the baby’s head is engaged in the pelvis. It then takes two hours for the baby to descend completely. You start to grow a woman only if the cervix is completely open.“
How long does cervical dilation last before delivery?
The duration of cervical dilation and opening varies from woman to woman, but in all cases it takes several hours. The expert points out that the cervix does not dilate one centimeter per hour contrary to what one might hear. “The dynamics of contractions at the beginning and end of labor must be taken into account.
“The cervix does not dilate one centimeter per hour, contrary to what we can hear”.
What to do when cervical dilation stagnates?
Sometimes it happens that the stagnant cervical dilation suddenly, when she seemed well engaged. In this case, health professionals often try to intervene as little as possible, and “to respect the physiology of work”, assures Marie Choquel.. If the situation persists, solutions can be used. “Whatever the act performed, we will always observe the sensations of the pregnant woman and the heartbeat of the baby.“, specifies the nurse.
“If the cervix is dilated to 4 cm and the contractions slow down, we can for example break the bag of waters. The pregnancy hormones thus released will soften the cervix and intensify labour.”. This may be enough to relaunch the dynamic, but in any case, specifies the midwife, we will allow ourselves a little time before re-examining. “If mom and baby are fine, we wait“, she indicates.
If labor does not resume, we can be led to inject oxytocinlittle by little, infusion: “If this works and the contractions resume, the mother-to-be will normally be able to give birth vaginally.”
“Otherwise, and if, for example, the baby’s heart rate shows signs of weakness, we may have to carry out a caesarean stagnation“, describes the specialist.
There are several methods to help the cervix open, but none are foolproof! For example, pregnant women can be encouraged to exercise, walk as much as possible, drink raspberry tea. “When the woman is already in labor, and depending on how she manages the pain, she will be offered to mobilize, walk, sit on the ball (the gym ball editor’s note)“lists the midwife.
“A pregnant woman who examines her cervix herself can actually feel something. But it’s still very abstract.”, notes the expert. She explains that midwives are used to feel the cervix and have above all been trained for this. Difficult then for a mother-to-be to appreciate the opening of her cervix and especially to estimate the number of centimeters of dilation.
Thanks to Marie Choquel, midwife in the Paris region.