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Theories of Labor Onset – any hallowed orga organ n when when stre stretc tche hed d to its its maxi maximu mum m capacity will contrast and empty. – Oxyt Oxytoc ocin in,, whic which h causes contractions of the smooth muscles of the posterior pituitary gland as a result of stressful event in labor. – Prog Proges este tero rone ne,, secr secret eted ed by the the corp corpus us Luteum and then by the the placenta, is essen ssenti tiaal in mainta intain inin ingg pregn regnaancy. cy. Howe Howeve ver, r, the the decr decrea ease se in the the leve levell of proge progeste steron ronee circul circulati ating ng in the body body will will initiate body pains. – Prostaglandins, formed by the uterine deciduas under level of concentration in the amniotic fluid and bloo blood d of wome women n incr increa ease sess duri during ng labo labor. r. Resear Research ch has has shown shown prosta prostagla glandi ndin n to be very effective in inducing uterine cont contra ract ctio ion n at any any stag stagee of gest gestat atio ion. n. Initiation of labor is said to be the result of the release of arachidonic acid is believed to increase prostaglandin synthesis contractions. – as the placen placenta ta matur matures, es, blood blood supply supply decrea decreases ses resulting in uterine contractions.
Related Terms:
Labor – is the process of moving the fetus, placenta and membranes out of the uterus and throug through h the birth birth can canal. al. Syn Synony onymou mouss with 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 aper apertu ture re larg largee enou enough gh to perm permit it the 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 – meas measur urem emen entt of the the prog progre ress ss of descent of the presenting part in relation to the ischial spine. Frequency – from from the the begin eginni nin ng of one one cont contra ract ctio ion n to the the begi beginn nnin ingg of the the next next contraction Duration – from the beginning of contraction to its completion Intensity – the strength of contraction to its completion Effacement – progre ogresssive sive thin thinn ning ing and shortening of the cervix Dilatation – opening of the cervix os during labor
SIGNS of LABOR Preliminary/Prodromal Preliminary/Pr odromal Signs of Labor settin ingg of feta fetall head head into into 1. Ligthening – sett pelvic brim occurs occurs appro approxim ximate ately ly 10-14 10-14 days days before labor begins giv gives the woman relie lief from diap iaphragmatic tic pressure and shortness of breath occurs early in primiparas mother mother may experien experience: ce: shooting shooting leg leg pains from the increased pres pressu sure re on the the sciati iaticc nerve rve, inc increa reased sed amoun ounts of vagin aginaal discha discharge rge and and urina urinary ry freque frequenc ncy y from pressure on the bladder 2. Increased in Level of Activity – related to an increase in epinephrine release that is initia initiated ted by a decrea decrease se in proges progester terone one produced by the placenta Braxto xton n Hic Hicks ks Co Contr ntrac actio tions ns – pain painle less ss 3. Bra irregular irregular contract contractions, ions, sometimes sometimes strong strong that may cause discomfort cervix – Goodell’s sign: the 4. Ripening of the cervix – cervix feels softer than normal similar to earlob earlobee throug throughou houtt pregna pregnancy ncy;; at term term cervix is described butter-soft Signs of TRUE LABOR: Uterine ne Cont Contracti ractions ons – sure surest st sign sign that that 1. Uteri 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 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. Moder Moderate ate – uter uterus us is moder moderate ately ly firm firm and a firmer pressure is needed to indent 3. Strong Strong – the the uterus uterus beco becomes mes very very firm firm that that at the height of contraction cannot be indented. COMPONENTS of LABOR COMPONENTS 1. Passage – refers to the shape and measurement of maternal pelvis and distensibility of birth canal – refe refers rs to the the rou route te a fet fetus us must must travel from the uterus through the cervix and vagina to the external perineum. – Elas Elasti ticc to exp expan and d and and acco accomm mmod odat atee 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
Passenger – – refers to the fetus, its size, 2. Passenger presentation, and position. Power – – forces acting together to expel 3. Power 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 the fou fourr bon bones es:: the the fron fronta tall (actually 2 fused bones), 2 parietal and occipital. - The The othe otherr fou four: r: sphe spheno noid id,, 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 t he coronal and sagittal sutures - diamond-shape - ante antero ropo post ster erior ior diam diamet eter er is 3-4c 3-4cm m - tran transv sver erse se diam diamet eter er is 2-3 2-3cm cm Posterior Fontanelle – lies at the junction of the lambdoidal and sagittal sutures. - triangular - smal smalle lerr tha than n the the ant anter erio ior r Fontanelle - only only 2cm 2cm acro across ss its its wid wides estt par partt Vertex – the space between two fontanelles Sinciput – the area over the frontal bone Occiput – the area over the occipital bone
Suboccipitobregmatic 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) Moder Moderate ate flex flexion ion – the chin chin is is not touching the chest but is in an alert or military position 3) Poor flexion flexion – the the back back is arched, arched, the the neck 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
a. Cephalic – the fetal head is the body part that will first contact the cervix - the four types of cephalic presentation: 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: 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 th e 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
0 station – presenting part of a fetus is at the level of the ischial i schial spines -4 station – head is at outlet
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 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: - Assi Assist stss wom woman an to cope cope with with contraction - Help Helpss to to con conce cent ntra rate te in brea breathi thing ng techniques - Assi Assist stss int into o com comfo fort rtab able le posi positi tion on - Info Inform rmss wom woman an of the the pro progr gres esss of of labor - Expl Explai ains ns proc proced edur uree and and rout routin ines es - Offe Offerr flui fluids ds,, ice ice chi chips ps,, food food as 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 •
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Nursing Care: - Find Findss asse assess ssme ment nt tec techn hniq ique uess between contractions - Assi Assist stss with with freq freque uent nt posit positio ion n change - Appl Applie iess cou count nter er pres pressu sure re to sacrococcygeal area - Enco Encour urag ages es and and prai praise sess - Keep Keepss woma woman n aw awar aree of prog progre ress ss
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Chec Check k blad bladde derr and and enco encour urag ages es 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
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2. Stage 2 (Stage of Expulsion) – the period from full dilatation to birth of the infant Contractions change from the characteristic crescendo-decrescendo 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
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Descent – downward movement of the biparietal diameter of the fetal head to within the pelvic inlet - full full des desce cent nt occu occurs rs and and the the feta fetall head extrudes beyond the dilated cervix and touches the posterior vaginal floor Flexion – the head bends forward onto the chest, making the smallest anteroposterior diameter 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 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 fore most parts of the head, the face and chin are born.
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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 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: - Len Lengthe gthen ning ing of of the the cord ord - Sudden gu gush of of blo bloo od - Chan Change ge of shap shapee of of the the uter uterus us b. Placental Expulsion - Brandt Andrew’s Maneuver – tract the cord slowly, winding it around the clamp until placenta spontaneously 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
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 done thro throug ugh h int inter ermi mitt tten entt auscultation - elec electr tron onic ic mon monit itor orin ingg 1. External – transabdominal, transabdominal, noninvasive, monitors uterine contraction and FHR; client needs to decrease extra-abdominal extra-abdominal movements 2. Internal – membranes must be ruptured, cervix sufficiently dilated and presenting part; invasive i nvasive 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 th e 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
