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Unformatted text preview: Labor and Delivery
April Grace E. Ochon What is Labor? Series of events by which uterine contractions and abdominal pressure expel the fetus and placenta from the woman s body Regular contractions cause progressive dilatation of the cervix and sufficient muscular force to allow the baby to be pushed to the outside. Normally begins when a fetus is sufficiently mature to cope with extrauterine life, yet not too large to cause mechanical difficulties with birth. In some instances, it begins before the fetus is mature (preterm birth) or delayed until the fetus and the placenta have both passed beyond the optimal point for birth (postterm birth). Theories of Labor Onset Uterine muscle stretching, which results in prostaglandin release Pressure on the cervix, which stimulates the release of oxytocin from the posterior pituitary Oxytocin stimulation, which works together with prostaglandin to initiate contractions Change in the ratio of estrogen to progesterone (increasing estrogen in relation to progesterone stimulates uterine contractions) Placental age, which triggers contractions at a set point Rising fetal cortisol levels, which reduce progesterone formation and increase prostaglandin formation Fetal membrane production of prostaglandin, which stimulates contractions Seasonal and time influences Preliminary Signs of Labor 1. Lightening 2. Increase in Level of Activity 3. Braxton Hicks Contractions 4. Ripening of the Cervix Lightening Also called descent of the fetal presenting part into pelvis Occurs 10-14 days before labor begins Changes the woman s abdominal contour as the uterus becomes lower and more anterior Abdominal pressure increases, result to shooting leg pains from pressure on sciatic nerve, increased amounts of vaginal discharge, urinary frequency Increase in Level of Activity Woman wakes in the morning full of energy due to an increase in epinephrine release that is initiated by a decrease in progesterone produced by the placenta. Additional epinephrine prepares the woman s body for the work of labor ahead. Braxton Hicks Contractions
Muscles of your uterus (womb) tightening, for anywhere from 30 to 60 seconds. This may happen to you several times an hour, several times a day starting the 28th week AOG.
False Contractions Begin and remain irregular. Felt first abdominally and remain confined to the abdomen and groin. Often disappear with ambulation and sleep. Do not increase in duration, frequency, or intensity. Do not achieve cervical dilatation. True Contractions Begin irregularly but become regular and predictable. Felt first in the lower back and sweep around to the abdomen in a wave. Continue no matter what the woman s level of activity. Increase in duration, frequency, and intensity. Achieve cervical dilatation. Ripening of the Cervix Internal sign seen only on pelvic examination Cervix becomes softer and it tips forward. Internal announcement that labor is close at hand. Signs of True Labor 1.Uterine Contractions 2.Show 3.Rupture of Membranes Uterine Contractions Surest way that labor has begun Effective, productive, involuntary initiation Show As the cervix ripens, the mucus plug that filled the cervical canal during pregnancy is expelled. The exposed cervical capillaries seep blood as a result of pressure exerted by the fetus. The blood, mixed with mucus takes on a pink tinge and is referred to as show or bloody show Rupture of the Membranes Sudden gush or scanty, show seeping of clear fluid from the vagina Early rupture can be advantageous if it causes the fetal head to settle snuggly into the pelvis, this can actually shorten labor. Two risks are intrauterine infection and prolapse of the umbilical cord, which can cut off the oxygen supply to the fetus. If labor has not spontaneously occurred by 24 hours after membrane rupture and the pregnancy is at term, labor will be induced to help reduce risks. Components of Labor 1. Passage 2. Passenger 3. Powers 4. Psyche Passage Route the fetus must travel from the uterus through the cervix and vagina to the external perineum. The fetus must also pass the pelvic ring. The woman s pelvis must be of adequate size and contour. Pelvic Inlet Pelvic Outlet Two pelvic measurements are important to determine adequacy of the pelvic size: the diagonal conjugate (anterior-posterior diameter of the inlet) and the transverse diameter of the outlet. At the pelvic inlet, the antero-posterior diameter is the narrowest; at the outlet, the transverse diameter is the narrowest. If disproportion between the fetus and the pelvis occurs, the pelvis is the structure at fault. Passenger Refers to the fetus. Head has the widest diameter. Whether a fetal skull can pass depends on both its structure and its alignment. Molding Change in shape of the fetal skull produced by the force of uterine contractions pressing the vertex against the notyet-dilated cervix. Lasts only for a day or two and is not a permanent condition Fetal Presentation and Position A.Complete Flexion B. Moderate Flexion C. Poor Flexion D. Hyperextension Attitude Describes the degree of flexion the fetus assumes during labor or the relation of the fetal parts to each other Engagement Settling of the presenting part of the fetus far enough into the pelvis to be at the level of the ischial spines, a midpoint of the pelvis Floating - presenting part that is not engaged Dipping
- Descending but has not yet reached the iliac psines Station Relationship of the presenting part of the fetus to the level of the ischial spines 0 station presenting part is at the level of the ischial spines (engagement) Minus stations presenting part is above the spines which range form -1 cm to -4cm Plus stations presenting part is below the spines which range from +1cm to +4cm Crowning presenting part is at the perineum and can be seen id the vulva is separated (+3 or +4 station) Fetal Lie Relationship between the long (cephalocaudal) axis of the fetal body and the long (cephalocaudal) axis of the woman s body. Whether the fetus is lying in a horizontal (transverse) or a vertical (longitudinal) position Types of Fetal Presentation
contact the cervix or deliver first denotes the body part that will first Cephalic head is the first part which contacts the cervix Breech either the buttocks or feet first contacts the cervix Shoulder fetus is lying horizontally in the pelvis so that its long axis is perpendicular to that of the mother Types of Fetal Position relationship of the presenting part to a specific quadrant of the woman s pelvis Four quadrants of the maternal pelvis: Right anterior Left anterior Right posterior Left posterior Four parts of the fetus as landmarks to describe relationship of the presenting part to one of the pelvic quadrants: Vertex presentation- occiput Face presentation- chin (mentum) Breech presentation- sacrum Shoulder presentation- scapula (acromion process) Middle letterlandmark fetal First letter if landmark point either to left or right of mother Last letter whether landmark points to anteriorly, posteriorly, or transversely. LOA (Left occiput anterior) most common fetal position ROA -2nd most frequent position Position most important because it influences the process and efficiency of labor ROA/LOA fetus delivers fastest ROP/LOP labor is extended Posterior positions more painful for mother because rotation of fetal head puts pressure on sacral nerves, causing sharp back pains. Methods to determine fetal position
1. Combined abdominal inspection and palpation 2. Vaginal examination 3. Auscultation of fetal heart tones 4. Sonography Powers of Labor Supplied by the fundus of the uterus Implemented by uterine contractions Process that causes cervical dilatation and then expulsion of the fetus from the uterus Uterine contractions Phases: 1. Increment- intensity of contraction increases 2. Acme when the contraction is at its strongest 3. Decrement- when the intensity decreases Contour Changes Upper portion becomes thicker and active preparing it to exert the strength necessary to expel the fetus when the expulsion phase of labor is reached Lower segment- thin-walled, supple, and passive so the fetus can be pushed out of the uterus easily Cervical Changes Effacement Shortening and thinning of the cervical canal 1-2 cm canal virtually disappears Occurs because of longitudinal traction from the contracting uterine fundus Dilatation Enlargement of the cervical canal from an opening a few millimeters wide to one large enough to permit the passage of the fetus Occurs as uterine contractions gradually increase the diameter of the cervical canal of the lumen by pulling the cervix up over the presenting part of the fetus Fluid-filled membranes press against the cervix. Psyche Psychological state or feelings that women bring into labor with them. Stages of First Stage of Labor
1. Latent Phase begins at the onset of regularly perceived uterine contractions and ends when rapid cervical dilatation begins Mild and short, lasting 20 to 40 seconds Cervix dilates from 0 to 3 cm. Lasts 6 hours in nullipara and 4.5 hours in multipara 2. Active Phase Cervical dilatation occurs more rapidly, going form 4 cm to 7 cm Contractions are stronger, lasting 40 to 60 seconds and occurring approximately 3 to 5 minutes Lasts 3 hours in nullipara and 2 hours in multipara 3. Transition Phase Maximum dilatation of 8 to 10 cm occurs and contractions reach their peak of intensity, occurring every 2 to 3 minutes with a duration of 60 to 90 seconds Second Stage of Labor Period from full dilatation and cervical effacement to birth of the infant Third Stage of Labor Placental Stage Begins with the birth of the infant and ends with the delivery of the placenta 1. Placental Separation occurs automatically as the uterus resumes contractions Placenta is ready to deliver when: Umbilical cord is lengthened Sudden gush of vaginal blood Change in the shape of the uterus Schultz placenta shiny and glistening from the fetal membranes Duncan placenta raw, red, irregular, presents at the vagina with the maternal surface evident 300-500 mL normal blood loss 2. Placental Expulsion Placenta is delivered either by the natural bearing down effort of the mother or by gentle pressure on the contracted fundus by the physician (Crede s maneuver) Mechanisms of Labor: Cardinal Movements of Labor 1. Descent Downward movement of the parietal diameter if the fetal head to within the pelvic inlet. Full descent occurs when the fetal head extrudes beyond the dilated cervix and touches the posterior vaginal wall. Occurs because of pressure on the fetus by the uterine fundus. Full descent may be aided by abdominal muscle contraction. 2. Flexion As descent occurs, pressure from the pelvic floor causes the fetla head to bend forward onto the chest. Aided by abdomina, muscle contraction during pushing. 3. Internal Rotation Head enters pelvis with the fetal anteroposterior head diameter in a diagonal or transverse position. The head flexes as it touches the pelvic floor, and the occiput rotates until it is superior, or just below the symphysis pubis, bringing the head into the best diameter for the outlet of the pelvis. Brings the shoulders, coming next, into the optimal position to enter the inlet of puts the widest diameter of the shoulders in line with the wide transverse diameter of the inlet. 4. Extension As the occiput is born, the back of the neck stops beneath the oubic arch and acts as a pivot for the rest of the head. The head thus extends, and the foremost parts of the head, the face and chin, are born. 5. External Rotation Almost immediately after the head of the infant is born, the head rotates back to the diagonal or transverse position of the early part of labor. The aftercoming shoulders are thus brought into an anteroposterior position, which is best for entering the outlet. The anterior shoulder is born first, assisted perhaps by downward flexion of the infant s head. 6. Expulsion Once the shoulder is born, the rest of the baby is born easily and smoothly because of its smaller size. This is expulsion and is the end of the pelvic division of labor. Maternal and Fetal Responses to Labor Physiologic Effects on Mother
1. 2. 3. 4. 5. 6. 7. 8. Increase in cardiac output Increase in white blood cell count Increase in respiratory rate/Hyperventilation Slight elevation in temperature Increase in insensible water loss Decrease in bladder tone Increased back pain Perineal pain Psychological Responses of the Woman in Labor
1. Fatigue 2. Fear 3. Cultural Influences Fetal Responses to Labor
1. Fetal heart rate decreases by as much as 5 bpm 2. Slight, unconsequential fetal hypoxia 3. Minimal petechiae, ecchymotic areas on fetus, capput succedaneum 4. Fuul flexion 5. Establishment of respiration Fetal Danger Signs
1. High or Low Fetal Heart Rate more than 160/less than 110 bpm 2. Meconium Staining 3. Hyperactivity 4. Fetal Acidosis Maternal Danger Signs
1. 2. 3. 4. 5. 6. Rising or falling of blood pressure Abnormal pulse Inadequate or prolonged contractions Pathologic retraction ring Abnormal lower abdominal contour Increasing apprehension Nursing Interventions For the Mother
1. Admitting client to birthing area after determining that client is in labor 2. Determining if client s membranes have ruptured 3. Encouraging family participation as appropriate with the labor process 4. Performing Leopold s maneuver and vaginal exams as appropriate 5. Monitoring maternal vital signs and fetal heart rate and patterns, reporting deviations and abnormalities 6. Assessing pain level, instituting positioning, breathing, relaxation, and other methods for pain control; administering analgesics as ordered 7. Providing ice chips, wet washcloth, or hand candy 8. Encouraging voiding atleast every 2 hours 9. Cleansing perineum and assisting with pad changes 10. Monitoring vaginal discharge, cervical dilation and effacement, posititon and fetal descent 11. Encourage bearing down 12. Evaluate pushing efforts and length of time in 2nd stage 13. Preparing supplies and equipment for surgery/ For the Baby
1. Verifying maternal and fetal heart rate response to uterine contractions during intrapartal care 2. Applying tocotransducer after determining fetal position via Leopold maneuver 3. Palpating to determine contraction intensity with tocotransducer use First Stage of Labor
1. 2. 3. 4. 5. 6. 7. 8. 9. Maternal and Health History review Physical examination Leopold s maneuver Assessing rupture of membranes Assessing pelvic adequacy Sonography Vital signs Laboratory Analysis Auscultation of fetal heat sounds 10.Assessment of Uterine Contractions Duration - Length of Contraction Timed from the moment the uterus first tenses until it has relaxed again Intensity mild/moderate/strong Frequency timed from the beginning of one contraction to the beginning of the next 12.Respect contraction time. 12.Promote change of positions. 12.Promote voiding and provide bladder care. 12.Offer support. Second Stage of Labor
1. 2. 3. 4. 5. 6. 7. 8. Preparing the place for birth Positioning for Birth Promoting effective second-stage pushing Perineal cleaning Episiotomy Birth Cutting and clamping the cord Introducing the infant Third Stage of Labor
1. Oxytocin 2. Placenta Delivery 3. Perineal repair Thank you! ...
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- Spring '11