Labor And Delivery

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Theories of Labor Onset

1. Uterine stretc h theory – any hallowed organ when stretched to its maximum capacity will contrast and empty. 2. Oxy tocin th eory – Oxytocin, which causes contractions of the smooth muscles of the posterior pituitary gland as a result of stressful event in labor. 3. Progesterone Deprivation Theory – Progesterone, secreted by the corpus Luteum and then by the placenta, is essential in maintaining pregnancy. However, the decrease in the level of progesterone circulating in the body will initiate body pains. 4. Prostaglandin Theory – Prostaglandins, formed by the uterine deciduas under level of concentration in the amniotic fluid and blood of women increases during labor. Research has shown prostaglandin to be very effective in inducing uterine contraction at any stage of gestation. Initiation of labor is said to be the result of the release of arachidonic acid is believed to increase prostaglandin synthesis contractions. 5. Theory of Aging Placen ta – as the placenta matures, blood supply decreases resulting in uterine contractions. Related Terms:  Labor – is the process of moving the fetus, placenta and membranes out of the uterus and through the birth canal. Synonymous with childbirth and parturition.  Delivery – is the actual birth of baby  Crowning – encircling of the largest diameter of the baby’s head by the vulvar ring  Effacement – shortening and thinning of the cervical canal. It is expressed in percentage (%).  Dilatation – is the enlargement of the cervical os from an orifice a few millimeters in size to an aperture large enough to permit the passage of the fetus.  Show – is a mucoid discharge from the cervix that is present after the mucous plug has been discharged.  Attitude – the relationship of the fetal parts to one another  Lie – relationship of the fetal spine to the spine of the mother.

 Presentation – portion of the fetus that enters the pelvis first.  Position – relationship of the assigned area of the presenting part of the landmark of the material pelvis.  Station – measurement of the progress of descent of the presenting part in relation to the ischial spine.  Frequency – from the beginning of one contraction to the beginning of the next contraction  Duration – from the beginning of contraction to its completion  Intensity – the strength of contraction to its completion  Effacement – progressive thinning and shortening of the cervix  Dilatation – opening of the cervix os during labor SIGNS of LABOR Preliminary/Prodromal Signs of Labor 1. Ligthening – setting of fetal head into pelvic brim  occurs approximately 10-14 days before labor begins  gives the woman relief from diaphragmatic pressure and shortness of breath  occurs early in primiparas  mother may experience: shooting leg pains from the increased pressure on the sciatic nerve, increased amounts of vaginal discharge and urinary frequency from pressure on the bladder 2. Increased in Level of Activity – related to an increase in epinephrine release that is initiated by a decrease in progesterone produced by the placenta 3. Braxton Hicks Contractions – painless irregular contractions, sometimes strong that may cause discomfort 4. Ripening of the cervix – Goodell’s sign: the cervix feels softer than normal similar to earlobe throughout pregnancy; at term cervix is described butter-soft Signs of TRUE LABOR: 1. Uterine Contractions – surest sign that labor has begun

2. Show – the blood mixed with mucus, takes on a pink tinge. It is when mucus plug is expelled and capillaries are exposed. 3. Rupture of the membranes – experienced either as a sudden gush or as a scanty, slow seeping of clear fluid from the vagina. False Labor:  Irregular contractions  Pain is confined to the abdominal  No increase in duration, frequency, and intensity.  Pain disappears with ambulating  No cervical change  Sedation stops contractions True Labor:  Regular contractions  Pain on the lower back to the abdomen  Increase in duration, frequency and intensity  Pain not relieved upon ambulating  Accompanied with effacement and dilatation  Sedation does not stop contraction CHARACTERISTICS of CONTRACTIONS 1. Mild – uterine muscle are somewhat tense but can be indented by a gentle pressure 2. Moderate – uterus is moderately firm and a firmer pressure is needed to indent 3. Strong – the uterus becomes very firm that at the height of contraction cannot be indented. COMPONENTS of LABOR 1. Passage – refers to the shape and measurement of maternal pelvis and distensibility of birth canal – refers to the route a fetus must travel from the uterus through the cervix and vagina to the external perineum. – Elastic to expand and accommodate 4 Basic Classification of Pelvis: a. Gynecoid – best pelvis; half of the population b. Android – common in men, 20% in women; heart shape and difficult for vaginal delivery c. Anthropoid – common in men; 20-30%, pelvic inlet oval d. Platypelloid – flat pelvis; least common; 5% of the population, long sacrum

2. Passenger – refers to the fetus, its size, presentation, and position. 3. Power – forces acting together to expel fetus from the uterus 2 TYPES of POWER a. Primary Powers – involuntary contractions of the uterus b. Secondary Powers- voluntary bearing down efforts of the mother 4. Psyche – reflects the woman’s frame of mind in dealing with the labor experience Structure of the fetal skull  Cranium – uppermost portion of the skull, comprises eight bones. - the four bones: the frontal (actually 2 fused bones), 2 parietal and occipital. - The other four: sphenoid, ethmoid, and 2 temporal bones The Suture Lines:  Sagittal suture- joins the 2 parietal bones of the skull  Coronal suture – the line of juncture of the frontal bones and the 2 parietal bones  Lambdoid suture – the line of juncture of the occipital bone and 2 parietal bones. Fontanelles: - significant membrane-covered spaces that are found at the junction of the main suture lines Anterior Fontanelle – referred to as bregma; lies at the junction of the coronal and sagittal sutures - diamond-shape - anteroposterior diameter is 3-4cm - transverse diameter is 2-3cm Posterior Fontanelle – lies at the junction of the lambdoidal and sagittal sutures. - triangular - smaller than the anterior Fontanelle - only 2cm across its widest part Vertex – the space between two fontanelles Sinciput – the area over the frontal bone Occiput – the area over the occipital bone

Suboccipitobregmatic – narrowest diameter 9.5cm; from the inferior aspect of the occiput to the center of the anterior fontanelle Occipitofrontal – measured from the bridge of the nose to the occipital prominence is 12cm Occipitomental – the widest which is 13.5cm; measured from the chin to the posterior fontanelle Molding – the change in shape of the fetal skull produced by the force of uterine contractions pressing the vertex of the head against the notyet-dilated cervix.

+4 station – head is floating FETAL LIE – the relationship between the long axis of the body and the long axis of a woman’s body 2 Primary Lie 1. Longitudinal

2. Transverse

FETAL PRESENTATIONS – denote the body part that will first contact the cervix of be born first. - this is determined by a combination of fetal lie and the degree of flexion

FETAL PRESENTATION and POSITION 3 Main Presentations Attitude – describes the degree of flexion a fetus assumes during labor or the relation of fetal parts to each other 1) Good Attitude (complete flexion) – the spinal column is bowed forward that the chin touches the sternum, the arms are flexed and folded on chest, the thighs are flexed onto the abdomen and the calves are pressed against the posterior aspect of the thighs. 2) Moderate flexion – the chin is not touching the chest but is in an alert or military position 3) Poor flexion – the back is arched, the neck in extended and a fetus is in complete extension, presenting the occipitomental diameter of the head to the birth canal (face presentation) Engagement – refers to the settling of the presenting part of a fetus far enough into the pelvis to be at the level of the ischial spines. Floating – a presenting part that is not engaged Dipping – one that is descending but has not yet reached the ischial spines Station – refers to the relationship of the presenting part of a fetus to the level of ischial spines 0 station – presenting part of a fetus is at the level of the ischial spines -4 station – head is at outlet

a. Cephalic – the fetal head is the body part that will first contact the cervix - the four types of cephalic presentation: vertex, brow, face and mentum b. Breech – either the buttocks or the feet are the first body part that will contact the cervix - the 3 type of breech presentation: complete, frank, and footling) c. Shoulder – the presenting part is usually one of the shoulders (acromion process, an iliac crest, a hand, or an elbow POSITION – the relationship of the presenting part to a specific quadrant of a woman’s pelvis UTERINE CONTRACTIONS: Origins  Labor contractions begin a “pacemaker” point located in the myometrium near one of the uterotubal junctions  In some women, contractions appear to originate in the lower uterine segment rather than in the fundus. Phases  3 Phases: increment, acme, decrement  Increment- when the intensity of the contraction increases  Acme- when the contraction is at its strongest

 Decrement- when the intensity decreases  As labor progresses the relaxation intervals decrease from 10 minutes to 2 – 3 minutes  The duration also changes from 20-30 sec to a range of 60-90 sec

Contour Changes  Upper segment becomes thicker and active, preparing it to be able to exert the strength necessary to expel the fetus when the expulsion phase of labor is reached  The lower segment becomes thin-walled, supple, and passive so that the fetus can be pushed out of the uterus easily  Physiologic retraction ring – a ridge on the inner uterine surface that marks the boundary between the 2 portions  Pathologic retraction ring (Bandl’s ring) – it is a danger sign that signifies impending rupture of the lower uterine segment if the obstruction to labor is not relieved Cervical Changes Effacement  Shortening and thinning of the cervical canal  Normally the canal is 1-2cm  With effacement the canal virtually disappears because of longitudinal traction from the contracting uterine fundus Dilation  Refers to the enlargement or widening of the cervical canal from an opening of few millimeters wide to one large enough (10cm).  First reason why dilation occurs is uterine contractions gradually increase the diameter of the cervical canal lumen by pulling the cervix up over the presenting part of the fetus  Second, the fluid-filled membranes press against the cervix  As dilation begins there is large amount of vaginal secretions (show) because the last of the operculum or mucus plug in the cervix is dislodged and capillaries in the cervix rupture

STAGES OF LABOR

1. Stage 1 (stage of dilatation) – begins with the true labor pains and ends when the cervix has reached full dilatation Nursing Care: Stay with woman; provide constant support Reminds, reassures and encourages woman to reestablish breathing patterns and concentration as needed Prompts partial respirations if woman begins to push prematurely accepts woman inability to comply with instructions Keeps woman aware of progress 4 Phases: • Latent Phase Begins at the regularly perceived uterine contractions and ends when rapid cervical dilatation begins Contractions are mild and short lasting 20-40 seconds Cervix dilates from 0-3cm 6 hours in nullipara 4.5 hours in multipara Nursing Care: - Assists woman to cope with contraction - Helps to concentrate in breathing techniques - Assists into comfortable position - Informs woman of the progress of labor - Explains procedure and routines - Offer fluids, ice chips, food as ordered • Active Phase Dilatation increases from 4 – 7 cm Contraction lasts 40-60 sec and occur every 3-5 minutes 3 hours in nullipara 2 hours in multipara Show and spontaneous rupture of membranes may occur

Nursing Care: - Finds assessment techniques between contractions - Assists with frequent position change - Applies counter pressure to sacrococcygeal area - Encourages and praises - Keeps woman aware of progress

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Check bladder and encourages voiding - Gives oral care Transition Phase Contractions reached their peak of intensity occurring every 2-3 minutes with duration of 60-90sec Maximum dilatation 8-10cm Complete cervical effacement Woman experiences intense discomfort accompanied by nausea and vomiting Woman may also experience a feeling of loss of control, anxiety, panic or irritability

2. Stage 2 (Stage of Expulsion) – the period from full dilatation to birth of the infant Contractions change from the characteristic crescendo-decrescendo pattern to overwhelming uncontrollable urge to push or bear down with each contraction as if to move her bowels Woman perspire and the blood vessels in her neck may become distended Crowning takes place The need to push become intense and the woman cannot stop herself 6 Cardinal Movements of the Mechanism of labor o Descent – downward movement of the biparietal diameter of the fetal head to within the pelvic inlet - full descent occurs and the fetal head extrudes beyond the dilated cervix and touches the posterior vaginal floor o Flexion – the head bends forward onto the chest, making the smallest anteroposterior diameter o Internal rotation – the occiput rotates until it is superior, or just below the symphysis pubis, bringing the head into the best relationship to the outlet of the pelvis o Extension – as the occiput is born, the back of the neck stops beneath the pubic arch and acts as a pivot for the rest of the head. The head extends, and the foremost parts of the head, the face and chin are born.

o External Rotation – almost immediately after the head of the infant is born, the head rotates (from the anteroposterior position it assumed to enter the outlet) back to the diagonal or transverse position of the early part of labor o Expulsion – the rest of the baby is born easily and smoothly because of its smaller part size. The end of the pelvic division of labor. Nursing Care: Put both legs at the same time when positioning to the lithotomy position Instruct mother to push as fetal head crowns. If hyperventilation occurs, let patient breathe into a brown paper or a cupped hand. 3. Stage 3 (Placental Stage) – begins from the delivery of the baby up to the delivery of the placenta 2 Phases: a. Placental Separation Signs: - Lengthening of the cord - Sudden gush of blood - Change of shape of the uterus b. Placental Expulsion - Brandt Andrew’s Maneuver – tract the cord slowly, winding it around the clamp until placenta spontaneously comes out rotating it slowly so that no membranes are left Nursing Care: Don’t hurry the expulsion of the placenta, just watch for the signs of placental separation Take note of the time of placental delivery Inspect for the completeness of the placenta Palpate the uterus to determine degree of contraction. If relaxed, massage gently and apply ice cap Inspect for lacerations Types of Placental Presentation 

Schultze’s – appearing shiny and glittering from the fetal membranes

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Duncan – it looks raw, dirty, meaty, red and irregular

4. Stage 4 (Puerperium Stage) – first 4 hours after delivery of placenta Degrees of Perineal Lacerations: 1. First Degree – skin and superficial to muscle 2. Second Degree – muscles of the perineum 3. Third Degree – continues to anal sphincter 4. Fourth Degree – involves the anterior anal wall Episiotomy – incision made to the perineum to enlarge the vaginal opening for easy delivery Types: a. Midline/Median b. Mediolateral c. Lateral Advantages: 1. Enlarging of the vaginal opening 2. Shortening of the second stage of labor 3. Minimizing the stretching of the perineal muscle 4. Preventing perineal tearing Fetal Monitoring – periodic change or fluctuation in FHR occur in response to contractions and the fetal movements are described in terms of accelerations or decelerations - done through intermittent auscultation - electronic monitoring 1. External – transabdominal, noninvasive, monitors uterine contraction and FHR; client needs to decrease extra-abdominal movements 2. Internal – membranes must be ruptured, cervix sufficiently dilated and presenting part; invasive procedure; continuous monitoring - results of monitoring: normal FHR 120160; must obtain a baseline Acceleration – 15 bpm rise above baseline followed by return; usually in response to fetal movement or contractions; indicates fetal wellbeing Deceleration – fall below baseline lasting 15 seconds or more, followed by a return:

a. Early Deceleration – are periodic decreases in the FHR resulting from pressure on the fetal head during contraction (head compression) b. Late Deceleration – indicative of fetal hypoxia because of deficient placental perfusion (uteroplacental insufficiency) c. Variable Deceleration – occurs at unpredictable times during contractions and indicates cord compression Anesthesia – encompasses analgesia amnesia, relaxation and reflex activity. It abolishes pain perception by interrupting the nerve impulses to the brain. The loss of sensation may be partial incomplete, sometimes with loss of consciousness. Analgesia – refers to the alleviation of the sensation of pain or in the raising of the threshold for pain perception without loss of consciousness