The Labor Process Labor is the 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. A time of change, both ending and beginning for the woman, fetus and family. Woman uses all psychological and physical coping methods. Nursing Process Assessment Outcome Identification and Planning Implementation Outcome Evaluation Theories of Labor Onset Unknown Factors: Uterine muscle stretching releases prostaglandin's. Pressure on cervix stimulates release of oxytocin from posterior pituitary. Oxytocin stimulation, works together with prostaglandin to initiate contractions. Increasing estrogen in relation to progesterone stimulates contractions. Placental age, triggers contractions at a set point. Rising fetal cortisol levels, reduce progesterone formation and increase prostaglandin formation. Fetal membrane production of prostaglandin which stimulates contractions Seasonal and time influences. Signs of Labor Preliminary Signs of Labor: Before labor, the woman experiences subtle signs of labor. Teach how to recognize these. Lightening-descent of fetal presenting part into the pelvis. Occurs 10 to 14 days before labor begins. Shooting leg pains, increased vaginal discharge, urinary frequency. Increase in Level of Activity: Feeling full of energy due to increase in epinephrine release initiated by decreased progesterone produced by placenta. Braxton Hicks Contractions: Stronger 1 week to days before labor. Support if not true contractions. Ripening of the Cervix: Internal sign seen with pelvic exam. Cervix is butter-soft and tips forward. Signs of True Labor Uterine and cervical changes. Uterine Contractions: Surest sign that labor has begun. Effective, productive, involuntary uterine contractions. Show or Bloody Show: Blood mixed with mucus when the mucus plug is expelled. Pink tinged. Rupture of the Membranes: Either sudden gush or scanty, slow seeping of clear fluid from the vagina. Amniotic fluid continues to be produced until delivery of the membranes. Early rupture is good, fetal head settles snugly into the pelvis. Risks: infection and cord prolapse. Induce after 24 hours. Components of Labor Four integrated concepts: Passage Passenger Power of labor Psyche of the woman is preserved. 1. Passage: Route the fetus must travel from uterus through cervix and vagina to external perineum. Diagonal conjugate-anterior-posterior diameter of the inlet. Transverse diameter of the outlet. Pelvis structure at fault or fetal head is presented to the birth canal at a less than its narrowest diameter, not because the head is to large. Avoid negative thoughts about the baby. 2. Passenger: Fetus is the passenger and must pass through the pelvic ring. Depends on fetal skull and alignment with the pelvis. Structure of the Fetal Skull: Cranium-upper portion of skull 4 superior bones-fontal, 2 parietal, and occipital are important in childbirth. 4 at base of cranium-sphenoid bone, ethmoid bone and 2 temporal bones. Chin-mentum can be a presenting part. Suture lines allow cranial bones to move and overlap, thus molding or diminishing the size of the skull so it can pass through the birth canal. Fontanelles are membrane-covered spaces found at junction of the main suture lines. Compress during birth to aid in molding of the fetal head. Anterior fontanelle (bregma) lies a the junction of the coronal and sagittal sutures. Diamond shaped Anteroposterior diameter-3 to 4 cm. Transverse diameter-2 to 3 cm. Posterior fontanelle-lies at junction of lambdoidal and sagittal sutures. Triangular shape 2 cm. across widest part. Vertex-space between the two fontanelles Diameters of the Fetal Skull: Shape is wider anteroposterior than its transverse diameter. Fetus must present transverse diameter to the smaller diameter of the maternal pelvis. Biparital diameter-9.25 cm. Outlet space-9.5 to 11.5 cm. Engagement – setting of fetal head into the pelvis. Depends on degree of flexion of fetal head. Inlet-12.4 to 13.5 cm. Molding: Change in shape of the fetal skull produced by the force of uterine contractions pressing the vertex against the not yet dilated cervix. Overlap and cause head to become narrower but longer. Lasts 1 to 2 days not permanent. No skull molding occurs when fetus is breech; buttocks are first. Fetal Presentation and Position: Attitude-degree of flexion the fetus assumes during labor or relation of the fetal parts to each other. Good attitude-complete flexion: Spinal column bowed forward Head flexed forward-chin touches the sternum Arms flexed and folded on chest Thighs flexed onto abdomen and calves pressed against posterior aspect of thighs Ovoid shape Moderate flexion-military position-chin not touching the chest. Partial extension-brow of head presents first. Engagement – settling of presenting part of fetus far enough into pelvis to be at level of ischial spines, at midpoint of pelvis. Floating-a presenting part not engaged. Dipping-a presenting part that is descending but not yet reached iliac spines Assessed by vaginal and cervical exam. Station: Relationship of presenting part of fetus to level of ischial spines Station 0 - presenting part at level of ischial spines (head is engaged). Minus station – presenting part above the spines (-1cm to - 4cm) (floating). Plus station – presenting part is below the spines (+1cm to +4cm) at +3 to +4 station presenting part is at perineum and can be seen if vulva is separated (crowning). Fetal Lie: Lie is relationship between long axis of fetal body and long axis of woman’s body. 99% are longitudinal lie. Types of Fetal Presentation: Demotes the body part that will first contact the cervix or deliver first. Determined by fetal lie and degree of flexion (attitude). Cephalic presentation-head is the fetal part that first contacts the cervix. Four types: Vertex-best Brow Face Mentum Caput succedaneum-edematous area of fetal skull that contacted the cervix during labor. Breech Presentation: Buttocks or feet are the first body part to contact the cervix. 3% of births Affected by attitude Types: Complete Frank Footling Shoulder Presentation: Transverse lie, fetus is lying horizontally in the pelvis so long axis is perpendicular to mother. Presenting part-shoulders, iliac crest, hand or elbow. Fewer than 1% Cesarean birth Types of Fetal Position: Relationship of presenting part to a specific quadrant of the woman’s pelvis. Pelvis is divided into 4 quadrants according to the mother’s right and left. 1. Right anterior 2. Left anterior 3. Right posterior 4. Left posterior Abbreviations: (3 letters) Middle letter denotes fetal landmark: O for occiput, M for mentum or chin, SA for sacrum, A for acromion process. First letter defines whether the landmark is pointing to the mother’s right R or left L. Last letter defines whether the landmark points anteriorly A, posteriorly P, or transversely T. LOA-left occipitanterior- most common. ROP-right occipitoposterior-second Six common positions Position influences the process and efficiency of labor. Fastest-ROA or LOA Extended-ROP or LOP-more painful Importance of Determining Fetal Presentation and Presentation: Presentations other than vertex puts the fetus at risk. Implies proportional differences between fetus and pelvis. Methods to determine position, presentation and lie: 1. Abdominal inspection and palpation 2. Vaginal exam 3. Auscultation of fetal heart tones 4. Sonography Mechanisms of Labor (Cardinal Movements) A number of different position changes to keep the smallest diameter of fetal head presenting to the smallest diameter of the birth canal. Descent Downward movement of biparietal diameter of fetal head to within pelvic inlet. Flexion Fetal head bends forward onto chest. Suboccipitobregmatic diameter. Internal Rotation Head flexes as it touches pelvic floor, and occiput rotates until it is superior or just below the symphysis pubis, bringing head into best diameter for the outlet of pelvis. Brings shoulders into position to enter the inlet. Extension As occiput is born, back of neck stops beneath the pubic arch and acts as a pivot for the rest of the head. Head extends and foremost parts of head, face and chin are born. External Rotation Immediately after head of infant is born Head rotates from anteroposterior position back to diagonal or transverse position of the early part of labor. Anterior shoulder is born first, assisted by downward flexion of infant’s head. Expulsion Once shoulders are born, the rest of the baby is born easily and smoothly. End of the pelvic division of labor. Supplied by the fundus of the uterus. Implemented by uterine contractions A process that causes cervical dilatation Then expulsion After full dilatation of cervix power is abdominal muscles. Do not bear down with abdominal muscles until cervix is fully dilated. Could cause fetal and cervical damage. Uterine Contractions: Origin: Begin at a pacemaker point located in the myometrium near one of the uterotubal junctions. Each contraction begins at that point and then sweeps down over the uterus as a wave After a short rest period another contraction is initiated. In early labor, pacemaker is not synchronous Pacemaker becomes more attuned to calcium concentration in myometrium and begins to function smoothly. Phases 1. Increment-when intensity of contraction increases. 2. Acme-when the contraction is at its strongest. 3. Decrement-when intensity decreases. Between contractions the uterus rests 10 min.early labor, 2 to 3 min. later. Duration increasing from 20 to 30 seconds to a range of 60 to 90 seconds. Contour Changes Upper-becomes thicker and active, preparing to exert strength to expel fetus. Lower segment-becomes thin-walled, supple, and passive so it can be pushed out. Physiologic retraction ring-ridge on inner uterine surface. Contour changes to elongated. Pathologic retraction ring (Bandl’s ring)-abdominal indentation that is a danger sign of impending rupture of lower uterine segment. Cervical Changes: Effacement-shortening and thinning of the cervical canal (normal 1 to 2 cm.) Dilatation-enlargement of cervical canal from a few millimeters to 10 cm. Increases diameter of cervical canal lumen by pulling cervix up over presenting part. Fluid filled membranes press against cervix. Psyche Psychological state or feelings that women bring into labor with them. Fright, apprehension,excitement, awe. Debriefing time. Stages of Labor Divided into 3 stages: First stage of dilatation-beginning with true labor contractions and ending with cervix fully dilated. Second stage-from time of full dilatation until the infant is born. Third or placental stage-from the time the infant is born until after delivery of the placenta. Fourth stage-first 1 to 4 hours after birth of the placenta. First Stage of Labor Divided into 3 phases: 1. Latent 2. Active 3. Transition Latent phase: Preparatory phase-begins at the onset of regularly perceived uterine contractions and ends when rapid cervical dilation begins. Contractions-mild and short 20 to 40 sec. Cervical effacement occurs Cervix dilates from 0 to 3 cm Phase lasts approx. 6 hours in nullipara and 4.5 hours in multipara. Analgesics given too early in labor will prolong this phase. Walking, preparation for birth, packing, care for siblings. Active phase: Cervical dilatation occurs more rapidly, from 4 cm to 7 cm. Contractions are stronger, lasting from 40 to 60 sec., every 3 to 5 min. Phase lasts from 3 hours in nullipara to 2 hours in multipara. Show and rupture of membranes may occur. True discomfort. Dilatation 3.5 cm in nullipara per hour to 5 to 9 cm in multipara per hour. Analgesics has little effect on progress of labor. Transition Phase: Dilatation 8 to 10 cm occur Contractions at peak of intensity every 2 to 3 min. with duration of 60 to 90 sec. If membranes not ruptured, will rupture at 10 cm. If not occurred-show will be present and mucus plug is released. First Stage of Labor Full dilatation and complete cervical effacement occur. Intense discomfort and nausea/vomiting, feeling of loss of control, anxiety, panic, irritability. Her focus is inward on task of birthing. Peak is identified by slight slowing in rate of dilatation when 9 cm is reached (deceleration on graph). At 10 cm irresistible urge to push. Second Stage of Labor Full dilatation and cervical effacement to birth of infant. Contractions change from crescendo-decrescendo pattern to uncontrollable urge to push. N/V, she perspires, blood vessels in neck become distended. Perineum begins to bulge and appear tense. Anus appears everted, stool expelled, vaginal introitus opens, fetal head visible. Crowning – at first slitlike opening then oval, then circular, from size of dime to that of a quarter, then half-dollar. She can not stop pushing, all energy is directed toward birth. Third Stage: Placental stage begins with the birth of the infant and ends with delivery of the placenta Two separate phases: Placental separation Placental expulsion Third Stage of Labor After birth the uterus can be palpated as a firm, round mass, inferior to level of umbilicus. Uterine contractions begin again and organ assumes a discoid shape until separated, approx. 5 min. Placental Separation: Occurs automatically as uterus resumes contractions. Folding and separation of the placenta occurs. Active bleeding on maternal surface of placenta and this helps separate the placenta by pushing it away from its attachment site. Signs: Lengthening of the umbilical cord Sudden gush of vaginal blood Change in the shape of the uterus Schultze-shiny and glistening side of placenta fetal surface. (80%) Duncan-looks raw, red irregular with ridges, maternal surface. Third Stage of Labor Normal blood loss-300 to 500 ml. Placental Expulsion: After separation, the placenta is delivered by natural bearing down effort or gentle pressure on fundus by physician. Never apply pressure to uterus in uncontracted state or uterus may evert and hemorrhage. Placenta can be removed manually. Saved for stem cell research. Responses to Labor Maternal Response: Almost all body systems are affected. Cardiovascular Cardiac output Blood pressure Hemopoietic system Respiratory Temperature regulation Fluid balance Urinary Musculoskeletal Gastrointestinal Neurologic and sensory Psychological Responses: Fatigue Fear Cultural influences Fetal responses: Neurologic system Cardiovascular Integumentary Musculoskeletal Respiratory Danger Signs of Labor Fetal Danger Signs: High or low fetal heart rate Meconium Hyperactivity Fetal acidosis Maternal Danger Signs: Rising or falling blood pressure Abnormal pulse Inadequate or prolonged contractions Pathologic retraction ring Abnormal lower abdominal contour Increasing apprehension Assessment During Labor Once a woman arrives at a birthing facility: Initial Interview and Physical Examination: Extent of woman’s labor General physical condition Preparedness for labor and birth Ask: Expected date of birth Frequency, duration and intensity of contractions Amount and character of show Rupture of membranes Vital signs – assess between contractions Time she last ate Drug allergies Past pregnancy history and outcomes Her birth plans (analgesia, who cuts the cord) This establishes whether she is in active labor and needs intense care or earlier stage of labor and interventions can be paced. Detailed Assessment During the First Stage: History: Current pregnancy history Past pregnancy history Past health history Family medical history Physical Examination: Includes pelvic exam to confirm presentation and position of fetus and stage of dilatation. Abdominal assessment Estimate fetal size by fundal height (xiphoid) Presentation and position Palpate and percuss bladder Abdominal scars (adhesions) Skin turgor Leopold’s Maneuvers: Observation and palpation to determine fetal presentation and position. Assessing Rupture of Membranes: 1 of every 4 labors are spontaneous Sterile vaginal exam pH > 6.5 alkaline, nitrazine paper=blue or fern pattern under microscope. Normal color clear, green is meconium, yellow indicates blood incompatibility. Vaginal Examination: Extent of cervical effacement and dilatation Confirm presentation, position, and degree of descent. Can be done during contractions but is more painful Do not do exam if bleeding present. Assessment of Pelvic Adequacy: Not routine unless no prenatal care Internal conjugate and ischial tuberosity size Sonography: Determines diameter of fetal skull, presentation, presenting part, position, flexion, degree of descent. Vital Signs: T – q 4 hours if membranes ruptured q2hrs P- q 4hours – 70 to 80 bpm R – q 4 hours – 18 to 20/min B/P – q 4 hours – rises 5 to 15 mm Hg with contraction Laboratory Analysis: Blood-H&H, VDRL, Hep B antibodies, blood type Urine-protein, glucose, UA Assessment of Uterine Contractions: Length-duration-use monitor or palpate Intensity-strength-rated as mild, moderate, strong (unable to indent uterus) Frequency-from beginning of one contraction to the beginning of next one. Initial Fetal Assessment Auscultation of Fetal Heart Sounds: Best heard through the fetal back Count every 30 min. at beginning labor Every 15 min. during active labor Every 5 min. during second stage of labor Electronic Monitoring External Electronic Monitoring: Monitors both uterine contractions and FHR continuously or intermittently Sensors are strapped to the woman’s abdomen. Transducer placed over the fundus and ultrasound sensor for the fetus at the level of the fetal chest. Internal Electronic Monitoring: Most precise method Pressure sensing catheter passed through the vagina. Inserted after membranes have ruptured and 3 cm dilated. Monitors frequency, duration, baseline strength, peak strength Latent phase 5 mm Hg Active contractions 12 mm Hg Second stage 20 mm Hg FHR recording from scalp electrode When fetal head is engaged, electrode is inserted vaginally and attached to scalp. Invasive procedure, risk of uterine infection, limits woman’s movement. Telemetry Allows monitoring of both FHR and uterine contractions; free of connecting wires. An internal pressure uterine lead is inserted and fetal scalp electrode is attached, a miniature radio transmitter is placed in the vagina that signals to a monitor. Allows the woman to ambulate. Fetal Heart Rate Tracing: Trace FHR and duration and interval of uterine contractions onto paper rolls. Uterine contractions on bottom half FHR on top half Count number of bold vertical lines (space between two bold lines represent 60 sec. Fetal Heart Rate Patterns Evaluates 3 parameters: Baseline rate Variabilities in the baseline rate (long term and short term) Periodic changes in the rate (acceleration and deceleration) Electronic Monitoring Baseline FHR: Determined by analyzing a range of fetal heart beats recorded on a 10 min. tracing obtained between contractions. Normal 120-160 bpm Bradycardia – below 120 bpm for 10 min. <100 bpm is sign of hypoxia Tachycardia – 160 or more for 10 min. >180 bpm Variability: Most reliable indicators of fetal well-being. Is variation or differing rhythmicity in heart rate over time and is reflected on FHR tracing as a slight irregularity or jitter to the wave. Long term-LTV-fluctuations in FHR of 6 to 10 beats occurring 3 to 10 times / min. Short term-STV- difference between successive heartbeats, 3 to 5 bpm Rated as present, decreased or absent Periodic Changes: Acceleration-temporary normal increases in FHR due to fetal movement or compression of the umbilical vein during contractions. Early Decelerations-are periodic decreases in FHR resulting from pressure on fetal head during contractions. Slowing of FHR. Follows pattern of contraction beginning when contraction begins and ending when contraction ends. Waveform is inverse to contraction Lowest point of deceleration occurs with peak of contraction. (mirror image) Rate rarely falls below 100 bpm and returns quickly to 120 and 160 bpm Normally occurs late in labor If early in labor cause for concern Late Decelerations: Delayed until 30 to 40 sec after onset of contraction and continue beyond end of contraction. Suggests uteroplacental insufficiency or decreased blood flow through intervillous spaces during uterine contractions. Lowest point of deceleration occurs near the end of the contraction instead of at the peak. Oxytocin-stop or slow rate, change positions, administer IV or O2 Prolonged deceleration last longer than 2 to 3 min but less than 10 min. Cord compression or maternal hypotension Variable Decelerations: Unpredictable times in relation to contractions. Indicates compression of cord Change woman’s position from supine to lateral or to trandelenburg Administer fluids and O2 May need amnioinfusion Amnioinfusion: The addition of fluid into the uterus to supplement amniotic fluid. Prevents additional cord compression Sterile catheter is introduced through cervix into uterus. Attached to IV tubing and warmed NS or LR is infused rapidly. 500ml initially then rate is adjusted to infuse the least amount to maintain a monitor pattern without variable decelerations. Keep woman in lateral recumbent position Maintain aseptic technique Monitor temp q 1 hr Change bed frequently due to continuous flow of solution. If vaginal leakage stops means head is engaged and fluid will remain in uterus which may lead to hydramnios or uterine rupture. Sinusoidal FHR Pattern: CNS control of heart pacing so impaired that pattern resembles a undulating wave Nonperiodic Changes: Decelerations or accelerations changes that occur at times other than when the uterus is contracting. Due to fetal movement, change in maternal position, or administration of analgesia. Other Assessment Technique Scalp Stimulation: Apply pressure with fingers to fetal scalp Tactile response increased FHR If fetus is in distress and becoming acidotic FHR will not increase Assesses acid base balance in fetus Fetal Blood Sampling: Composition determine hypoxia before ECG (pH decreased < 7.20 = hypoxic Sample taken from scalp into capillary tube Acoustic Stimulation: Sharp sound next to woman’s abdomen to produce FHR acceleration. Care During First Stage of Labor Starts at beginning of contractions and ends when cervix is fully dilated. Helping the woman feel confident in pain control, progress of labor and physiologic stability. Give frequent progress reports. Respect Contraction Time and do not interrupt the woman during breathing exercises. Promote Change of Positions walking, kneeling, squatting Promote Voiding and Provide Bladder Care. A full bladder impedes fetal descent. Void q 2 to 4 hours, catheterize if needed. Hyperventilation (resp. alkalosis) breath in paper bag. Offer Support give a cool cloth, TLC Respect and Promote the Person’s Activities, allow them to remain with the woman throughout the birth. Support the Woman’s Pain Management Efforts Amniotomy artificial rupturing of membranes with amniohook or hemostat. Risk for cord prolapse Monitor FHR immediately Care During Second Stage of Labor Full cervical dilation to birth of the newborn. Preparing the Place of Birth Birthing Room Positioning for Birth Lithotomy-raise both legs up at the same time to prevent back and lower abdominal strain. Lateral, Sim’s, dorsal recumbent, semisitting and squatting. Promoting Effective Pushing: Must push with contractions and rest between them. Allow her to push when she feels the urge, use the position and technique she chooses. Semi fowlers, squatting, all fours. Do not hold breath when pushing always breath out. Panting with contraction is used to prevent her from pushing. Breath with her and take deep cleansing breath. Perineal Cleaning: Clean from vagina outward Episiotomy: Surgical incision of perineum made to prevent tearing of the perineum with birth and to release pressure on the fetal head with birth. Mediolateral have an advantage over midline cuts, tearing occurs away from the rectum. Substitutes a clean cut for a ragged tear. Minimizes pressure on fetal head Shortens last portion of labor Pressure of fetal presenting part against perineum deadens nerve endings so an episiotomy may be done without anesthesia. Pressure of the fetal presenting part also seals the cut edges and minimizes bleeding. Birth: As soon as the head of the fetus is prominent (8 cm) the Dr. may place a sterile Towel over rectum and press forward on fetal chin while the other hand presses downward on the occiput. This helps fetus achieve extension, so head is born with the smallest diameter presenting. Also controls the rate at which the head is born. Never apply pressure to the fundus of the uterus to effect birth, because uterine rupture may occur. Woman pushes until occiput of the fetal head is firmly in the pubic arch. The head is born between contractions. (panting)(flash of pain or burning sensation) Suction infant’s mouth and feel neck for cord and gently remove it if present by drawing over the fetal head. If tight it must be clamped and cut before shoulders are delivered. Push again without a contraction to deliver the shoulders. Downward pressure on head. Delivers the anterior shoulder. External rotation occurs and upward pressure on side of head delivers posterior shoulder. The remainder of the body slides free and when whole body is delivered this is the time of birth recorded. Cutting and Clamping the Cord: Hold infant in dependent position and suction with bulb syringe. Lay infant on abdominal drape while cord is cut. Place 2 Kelly hemostates placed 8 to 10 inches from infant’s umbilicus, and is cut between them. An umbilical clamp is applied. Obtain a sample of cord blood and count the vessels. Clamping the cord is part of the stimulus that initiates a first breath. Introducing the Infant: Use sterile blanket and hold firmly because the baby is very slippery. Lay infant on radiant heat warmer and dry with warmed towel. Cover head with cap and wrap infant snugly Take to mother and father. May breast feed which stimulates the release of endogenous oxytocin. Care During Third Stage of Labor From the time of the birth until the placenta is delivered. Fourth stage includes the first few hours after birth. Oxytocin:(Pitocin) Once placenta is delivered oxytocin is administered IM or IV (8 hours) Increases uterine contractions and minimizes uterine bleeding. Methergine last several hours. Check B/P for hypertension Placenta Delivery: Spontaneous or manual removal within 5 min. Inspect to be certain it is intact and normal in appearance and weight. 1/6th weight of infant. Perineal Repair: Long tedious process Immediate Postpartal Assessment VS q 15 min for 1 hour Palpate the fundus for size, consistency, and position. Observe the amount and characteristics of the lochia. Perform peri care and apply a pad. Clean gown and warm blanket Aftercare: Fourth stage of labor High risk for hemorrhage Concerns of Woman in Labor Woman Without a Support Person: Woman Who Will Be Placing Her Baby Up For Adoption: Hold baby, has a number of days to decide. Support Vaginal Birth After Cesarean Birth: Low transverse incision she may try. Risk for uterine rupture. Less painful afterwards.