First Stage Of Labour In Pregnant Women

September 22, 2024 adminPosted in Explore

In this article we are going to be guiding you on all you need to know about the first stage of labour.

First stage of labour is defined as the stage of cervical dilatation. However, it begins when there are regular rhythmic contraction and retraction of the uterus muscles and end with the full dilatation of cervix(10cm dilated).

The Physiological Processes That Occur During The First Stage of Labour

Below are the physiological changes that occur in a pregnant woman during the first stage of labour;

1. Duration of Labour

this varies with individual and is influenced by parity, birth intervals, psychological state of the woman, presentation and position of the fetus, shape and size of the maternal pelvis, and character of the uterine contraction.

2. Fundal Dominance

this explains the fact that uterine contraction begins and last longer at the uterine fundus before spreading across and downward to the other part of the uterus.

3. Polarity

this is the neuromuscular harmony between the two pole of the uterus (upper and lower poles) throughout labour.

4. Uterine contraction

this is the temporary shortening of the uterine muscle fibres which returns to its original length during relaxation.

5. Retraction

this is the relaxation of the uterine muscle fibres with some degree of shortening which takes place continuously in labour.

6. Formation of upper and lower segments

this occurs later in pregnancy or early hours in labour. The upper segment formed by the fundus is responsible for contraction and retraction while the lower segment which is formed by the isthmus and cervix distends and dilates aided by the pressure of the presenting part.

7. Formation of retraction ring

the retraction ring is an invisible transverse line or ridge of demarcation between the two uterine segments. If it becomes visible abdominally, it is an indication of obstructed labour and is called Bandl’s ring.

8. Cervical effacement

this is the inclusion of the cervical canal into the lower uterine segment.

9. Cervical dilatation

this is the widening of the os-uteri to such an extent that the product of conception can pass through.

10. Show

this is the blood stained mucous discharge seen a few hours before or few hours after the commencement of labour.

12. Formation of fore-water

the fore water is the amniotic fluid in front of the presenting part. As the lower uterine segment stretches, the chorion detach and bulge downwards to a depth of 6-12mm; the well applied head then cuts off the fluid in front of it from that behind (hind water)

13. General fluid pressure

when the membrane are intact, the pressure of uterine contractions is exerted on the amniotic fluid. Since the fluid is incompressible, the pressure is equalized throughout the uterus and over the fetal body.

14. Rupture of membrane

this normally occurs at the end of the first stage of labour.

15. Fetal axis pressure

this is the force of fundal contraction transmitted to the upper pole of the fetus down the long-axis of the fetus and applied to the cervix by the presenting part.

Medical Care of a Patient During The First Stage of Labour

Admission;

Welcome her warmly as she walks into the ward.
Give her a seat to sit comfortably while the antenatal notes are being retrieved from the record department.
Study the notes carefully to note any possible instruction from the obstetrician.
Take appropriate history from the patient such as the date and time of the first regular rhythmic uterine contraction, its frequency, strength and duration.
Ask for any presence of show, time and date.
Ask if the membranes have ruptured; noting the date and time and also colour, odour, and quantity of liquor.
If membranes have ruptured place a clean perineal pad over the perineum to minimize risk of infection.

General examination;

Perform head to toe examination to exclude anaemia, oedema, infection and varicose vein.

Abdominal Examination;

Examine the abdomen for the following;

Presence of scar which could be suggestive of previous surgery of the reproductive tract such as caesarean section or myomectomy.
To evaluate symphisio-fundal height for estimated gestational age.
To determine the presentation through pelvic palpation.
To ascertain the position through lateral palpation.
To auscultate the fetal heart sound.

Vaginal Examination;

This is performed every four hourly and not frequently while maintaining aseptic techniques to;

Confirm abdominal palpation.
Observe the state of the membrane if they are intact or ruptured.
Exclude cord prolapse, if membranes are ruptured.
Determine the degree of cervical dilatation.
Determine the station of the presenting part.
Observe whether the vagina is roomy enough or not, whether it is hot, warm or cold(it should warm) or whether it is moist or dry.
Note whether the cervix is thick or thin, whether it is effaced or not. Note the degree of dilatation, if it already dilating.
Note the presenting part, its position and the adequacy of the maternal pelvis.

Psychological Care;

Provide emotional support which include advocacy, explanation of her condition to her, praising and encouraging her
Reassure her to instill hope in her.
Ensure that you keep her informed about the progress of labour.
Make her know that you and the other members of the medical team are there for her.

Physical Support;

This includes walking around with her, holding her hands, rubbing her back when necessary, wiping her face, fanning her and encouraging a cold bath.

Position and Mobility;

Encourage her to adopt upright position as she will experience less pain and suffer less perineal trauma.
Encourage her to deliver in a position that is most comfortable for her.
Encourage her to deliver in a position that is most comfortable for her.
Encourage her to walk around during the first stage provided that the membranes are still intact. This will promote comfortable and more efficient contractions which in turn promotes engagement and descent of the presenting part. It also distract the woman from the discomfort of contraction.
Encourage frequent change in position to facilitate fetal rotation and descent.

Relief of Pain;

One of the following could be helpful in relieving labour pain;

Encourage her to have a warm bath or shower.
Use diversional therapy.
Emotional support like encouraging and being with her.
Use of prescribed drugs.

Nutrition;

she should not take food orally in case of emergency caesarean section.
If she is too thirsty, she may be given sips of water or moisten her lip with water.

Bowel and Bladder Care;

If she has not emptied her bowel for the past twenty four hours, she may be given enema(although this method is no longer in use) to have a clean delivery field and to prevent the woman from being embarrassed.
Encourage her to pass urine frequently or pass a urinary catheter to empty the bladder if she can’t.
Test urine for presence of glucose, protein and acetone.

Observation and Recordings;

Observe vital signs every four hours and record.
Observe fetal heart rate every two to four hours using fetal stethoscope(fetoscope)
Observe the progress of labour by noting the frequency and strength of uterine contraction and the descent of the presenting part, and make sure all observations are recorded.
The use of partograph; the midwife should use partograph to record all the salient features of labour in order to note any deviation from normal. Observations charted on partograph include the progress of labour using cervical dilatation, fetal condition, the maternal condition using pulse rate, blood pressure e.t.c
Continue to monitor and record findings until the second stage of labour has commenced.

We hope this information was helpful. Feel free to ask your questions in the comment section below.