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23. Augmentation and Management of Labor
23.1 Introduction
Management of labor is the term used for all the procedures done to help the pregnant woman, once she starts labor pains and till she delivers the newborn. Labor can be progressed in its natural way during all the three stages of it without much interference from attending obstetricians and staff members. An average time period from the initiation of labor pains to the delivery of the newborn (I-D interval) ranges from 12 to 18 h in primigravida and 8 to 10 h in multigravida. It has been proved that the longer the duration of this I-D interval, the more are the chances of infection, dehydration, fatigue, chest pain, body pain and the psychological effect on the mother to be. It can cause disturbances in the vital data like irregular and slow foetal heart rates, brain damage and lung infection in the newborn. These can be described as maternal and foetal morbidities.
O’driscoll and Friedman have studied such labors and have concluded that labor should be conducted actively rather than its own natural way. No labor period in primigravida (I-D interval) should be more than 12 h. Close supervision, timely intervention, tender loving care and constant encouragement to the woman in labor should be the KEY factors in managing labor patients. Primary aim should be to deliver the newborn within the time period of 10–12 h in primis.
23.2 Management of Labor
A woman in labor is extremely apprehensive and emotional for her course of labor and its outcome. The hours she passes in labor pains, the mechanical process of labor and delivering the foetus through narrow vaginal canal are most disturbing, distressing and painful.
Tender care, soothing words, soft touch and constant encouragement boost up the spirit and stamina of the pregnant woman. It leads to smooth course of labor by making the uterine contractions more regular, effective and painless. Fear-tension-pain and dystocia make a vicious cycle, which must be broken.
23.3 O’Driscoll’s (Professor Emeritus National Maternity Hospital, Dublin) and Others’ Views
It is a good idea to be aware of ACTIVE MANAGEMENT OF LABOR, which originated in Dublin at the National Maternity Hospital (NMH).
A precise ‘beginning’ of labor.
The labor not lasting longer than 12 h.
Augmentation of contractions with oxytocin is given if dilatation does not increase at the precise rate.
The progress of the labor is charted on a graph called a partogram.
Every clinic should use the normal monogram of labor progress and should develop alert line-alert zone-action line and action zone of their own clinic and patients should be put on it for knowing progress and should listen the alarming bells at the earliest. The aim is that a happy mother delivers a happy and healthy newborn and both of them make obstetricians happier and cheerful.
23.4 Normal Labor: The Basics
The posture of the foetus at term is called as Attitude, and it indicates the relation of the foetal parts with each other. The normal attitude is such which corresponds to the inner shape and volume of the uterine cavity. Generally foetus is bent forward with back makes the convexity. The foetal head is so flexed that the chin touches the chest. The thighs are flexed over the abdomen. The arms are usually crossed over.
The lie is the relation of the long axis of the foetus to that of the uterus. The lie is usually longitudinal at term. The presenting part is the portion of the foetus at the level of the brim of the pelvis. Normally it is called cephalic presentation when the head lies at the brim of the pelvis. Position refers to the relation of the occiput, in case of cephalic presentation, to the brim of the pelvis. Most of the time, it is occipito anterior—left or right side. Accordingly it is known as left occipito anterior (LOA) or right occipito anterior (ROA). Left occipito lateral (LOL) is common.
23.5 Onset of Labor
Labor can be defined as series of events by which the mature foetus is expelled out from the mother through cervico-vaginal route. Normal labor conveniently refers to the expulsion of the foetus in cephalic presentation—more commonly in left or right occipito anterior position. The word ‘delivery’ refers to the actual birth of the baby. For the circumstances responsible for the commencement of the labor pains, there are different views and theories. The common dictum ‘when the fruit is ripe—it will fall’ applies also. It appears that labor is initiated and maintained not by a single reason but more than many theories are acting at a time to start labor pains. At term progesterone drop, excessive sensitization of myometrium to present oxytocin in blood and prostaglandins effectivity on myometrium are the reasonable theories for the onset of labor. The real fact is uterine contraction and retractions in the last few days of pregnancy do help in engagement of the foetal head in to the brim of the pelvis. The labor commences when these uterine contractions and retractions become more regular—coming at shorter intervals and more intensive and effective.
Labor commences by effacement of the cervix first.
The cervix first becomes shorter in length and then starts dilating.
- 1.
The first stage of labor begins with the first true labor pains and ends with the full dilatation of the cervix.
- 2.
The second stage of labor begins with the full dilatation of the cervix and ends with the birth of the newborn.
- 3.
The third stage of labor begins with the birth of the newborn and ends with the delivery of the placenta.
One hour after the placental expulsion is considered as fourth stage of labor by many schools of thoughts, as chances of post-partum haemorrhage are maximum during this 1 h.
The causes of labor pains may be due to hypoxia of the contracted muscle cells, compression of the nerves in the cervix and lower segment of the uterus and stretching of the cervix due to dilatation.
The interval between the onset of contractions diminishes gradually from 10 min to 2 min in the second stage of the labor. Relaxation of the uterus between the two contractions is necessary for the foetus to get maternal blood and oxygen to survive.
The duration of each contraction ranges from 20 to 40 s. Each contraction has three phases—increment, acme and decrement.
Under the influence of contraction and retraction in labor, the uterus is differentiated in to two portions. The upper segment is actively contracting and thicker. The lower segment is passively dilating and thinner. As labor progresses, the cervix merges into the lower segment of the uterus. In a nutshell, the upper segment contracts, retracts and expels the foetus, while the lower segment and cervix dilate in response to the activity of upper segment. Thus an expanded muscular tube is formed through which the baby can pass. Retraction is the temporary shortening of upper segment which will not go back to its original position after the true contraction of the uterus. This retraction helps the foetus to descent in to the pelvic cavity. The relaxation of the lower segment is just opposite to the retraction of the upper segment.
When upper segment contracts judiciously, the cervix gives the resistance. Because of this cervical resistance, force of the uterine contractions increases to the level that a time comes when it overcomes the resistance of the cervix. The result is the cervix first becomes shorter and then becomes dilated.
In short, labor may be regarded as contest between the FORCE of expulsion and the POWER of resistance provided by the cervix and pelvic muscles. Effacement or taken up of the cervix is shortening of cervical canal from 2 cm to almost nil. The taken up cervix ultimately merges with the lower uterine segment. Condition of external Os of the cervix remains the same. The cervix becomes thin and papery when it is fully effaced, but the cervical os remains little dilated of 1 cm only (tip of the finger). It starts dilating soon after to reach to full dilatation of the cervix—that is, 10 cm dilatation.
23.6 Pelvic Canal
The pelvic bones, ligaments and some important muscles make the bony birth canal—known as passage of the passenger, the foetus. Because of the irregular shape of the pelvic canal and the relatively large dimensions of the foetal head at different levels, it is evident that not all the diameters of the head can pass through the diameters of the pelvis. For that suitable accommodation of different foetal segments is required to the completion of the child birth.
By the end of the first stage of labor the uterine contractions causes two parts of the uterus.Upper—the active and Lower-the passive. Once the cervix starts dilating, presenting part starts descending slowly and steadily in the pelvic canal—in case of primis. During the course of labor, spontaneous rupture of amniotic membrane usually occurs. The total effect of all the above forces and adaptation leads to descent of the foetus in the pelvic canal and ultimately the delivery of the newborn through the vagina by adopting different positions turn by turn.
The cardinal movements of the foetus in the mechanism of labor are:
- 1.
Engagement.
- 2.
Descent.
- 3.
Flexion.
- 4.
Internal rotation.
- 5.
Extension.
- 6.
External rotation.
- 7.
Expulsion.
Though the above movements have been mentioned separately, it usually occurs with one another in the process of delivery.
23.7 The Clinical Course
The sinking of the foetal head into the pelvic cavity reduces the bulk of the uterus and abdominal enlargement of the pregnant mother. This is called ‘lightening’. After lightening, the patient is at ease. False labor pains occur during the last few days of confinement. They are irregular, mostly confined to the lower segment of the uterus and not associated with SHOW or dilatation of the cervix. False pains are relieved by simple analgesics.
Show is the blood-stained discharge from the vagina coming out from effaced cervical canal, and it is the cervical mucus. It mixes with the blood coming out due to separation of the membranes and some dilatation of the cervix. This blood-stained mucus—SHOW—is the first sign of labor pains even before the patient starts feeling pains of true labor contractions of the uterus. The average duration of the first stage of labor in primigravida is about 12–16 h—with marked individual variation.
In the second stage of labor, uterine contractions are long-lasting, usually 50–80 s, and come at 2- to 3-min intervals. During the second stage, the muscles of the abdomen are brought into play. In the second stage of labor, the head descends still further and bulges, and the perineum becomes thin, tense and stretched as the scalp of the foetal head is seen in the gap—which may or may not go back inside in between the contractions. If it remains there,making diameter of at least 3 inch by the scalp of the head, it is called CROWNING of head. This is the right moment of applying episiotomy cut to facilitate the delivery of the newborn. Now comes the attending obstetrician in active role to help deliver the baby without any problems. The next chapter is on normal conduction of labor.
After the successful delivery of the newborn, the uterus will tonically contract and retract. The size will reduce to a greater extent. Because of the disparity of the sizes of the uterine wall and placenta, the placenta will start separating from the uterine wall. There will be a sudden gush of bleeding, and the placenta will deliver with active help of the attending obstetrician. Once the placenta comes out, the uterus contracts to a hard cricket ball. The muscles of the uterus have a tendency to relax in between contraction, especially when she is on oxytocin drip. In such cases, drip should be continued to prevent post-partum haemorrhage.
23.8 Normal Labor: Standard Conduction
The fundamentals in conducting normal labor or delivery in the hospital set-up are very clear, and one must observe that the standards and precautions should always be maintained. Summarizing these facts will enable us to understand what more and what better can be done keeping the originality intact.
All knows about the old age fear of LABOR PAINS in the minds of primigravidas.
Doctor-patient relationship plays a great role in smooth conduction of labor. Unnecessary fear about labor pains, overheard talk from problematic neighbours and oversentimental reactions from friends and family members create fearful image of delivery in the blank mind of a pregnant woman. In a hospital practice of a maternity department, a special impression should be initiated from the first visit of a woman to the hospital and should be maintained seriously by the doctors and all the staff members till she delivers and even after that. Antenatal education and knowledge about labor plays a major role in eliminating wrong ideas about pregnancy and labor. Antenatal exercise should be taught to all pregnant patients. It promotes mind and muscle relaxation and breathing control and develops confidence in themselves.
It is taken for granted that in today’s hospital practice,through records of all the visits are kept in a standardized antenatal form. All pathological investigations and ultrasound examinations should be advised at regular intervals. The patient and her husband should be thoroughly instructed for the importance of regular check-ups, filing and keeping all the records and emergency numbers with them. The patient and her husband or near relatives should be taken to the place where she has to be admitted when labor pains start and introduced to the staff members at the registration counter.
They should also take the virtual visit to intensive labor care room and understand the names of common procedures of conduction of labor. If possible short film of labor conduction and child birth should be shown to all pregnant women to eliminate the fears and understanding of the facts.
23.9 Management of the First Stage of Labor
The first stage of labor starts from the first true labor pains and ends with full dilatation of the cervix. The average time period of the first stage of labor is 12–18 h in primigravida. Patients admit to the labor room at the different time of their first stage. It goes from just onset of labor to 3 cm dilatation of the cervix to any point of the first stage of labor. After routine protocol of admission, thorough general and physical examination including pulse, BP, CVS, and RS examination should be done and recorded. Abdominal examination is similar to the one carried out during each antenatal visit.
Uterine contraction details—intensity and frequency.
Lie, presentation and position of the foetus—longitudinal/cephalic/vertex/LOA.
Engagement of the head of the foetus.
Auscultation with stethoscope or fetoscope or Doppler gives the idea about foetal heart condition and wellbeing. The normal range of FHR is 120–160/min.
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