‹header›
‹date/time›
Click to edit Master text styles
Second level
Third level
Fourth level
Fifth level
‹footer›
‹#›
Labor is the bridge between pregnancy & motherhood. For the woman in labor, this is the most intense experience of pregnancy.
The process begins between 38 and 40th week. The exact cause of onset is not understood. There are several hypothesis: Progesterone withdrawal → relaxation of the myometrium, whereas estrogen stimulates myometrial contractions and production of prostaglandins. As you will learn later, prostaglandin E is used to induce labor.  During labor, prostagIandin →  the connective tissue in the cervix to soften, thin out, and open during labor. Oxytocin, a hormone produced by the pituitary, plays a major role in the onset and maintenance of contractions during the labor process. Corticotropin-releasing hormone makes the uterus more sensitive to oxytocin and the prostaglandins. Different theories for one of the most emotional experiences.
Start on Chapter 15. We’ll cover parts Chapters 15 through 20. Each chapter has Key Terms at the beginning and Chapter Highlights as summaries.
Final weeks of pregnancy: mother/baby prepare for birth. Five important factors : the passage, the fetus, the relationship between the passage and the fetus, the forces of labor, and psychosocial considerations.
Often called the 5 “P”s of Labor: Passageway, Passenger, Powers, Position, and Psychologic responses
 
 
PASSAGE : Birth passage  – 3 sections of “true pelvis” – inlet, pelvic cavity (midpelvis), & outlet. Four classifications : gynecoid ,  android, anthropoid, & platypelloid. 
See Table 15-2: Implications of Pelvic Type for Labor & Birth p 310 
The Caldwell-Moloy (1933) classification of pelvises is widely used to differentiate bony pelvis types.
See Figure 15-1 , p 311
Gynecoid is most common, with diameters favorable to vaginal delivery.
PASSENGER: Fetal head: Considerations: face, base of skull, & vault of cranium (roof). Bones in face fused but vault has movable bones; overlap under pressure – molding. Sutures –membranous spaces between bones; intersections – fontanelles (‘soft spot”) Landmarks: mentum – chin; sinciput – brow; vertex – space between fontanelles; occiput – occipital bone
 
 Fetal  attidude – relationship of fetal parts to one another: norm: mod flexion of head, flexion of arms unto chest, & flexion of legs to abdomen
Fetal lie – relationship of cephalocaudal axis (spinal column) of fetus to c. a. of mother longitudinal: parallel             transverse: fetal c.a. is 90° to woman’s spine
Fetal Presentation – determined by fetal lie and by the body part that enters the pelvic passage first. The portion of the fetus is referred to as the presenting part.  Fetal presentation may be cephalic, breech, or shoulder.
Presentation: Fetal presentation may be cephalic, breech, or shoulder. Cephalic (head) occurs 97%. Breech (feet) & shoulder may be difficult – called malpresentations.
Cephalic presentation, head is completely flexed onto chest; smallest diameter (suboccipitobregmatic) presents. The occiput is the presenting part.
In your book: Figure 15-6: Military- top of head Fig B ; brow – head is partially extended – largest diameter ©; face – (D).
Engagement – when largest diameter of presenting part reaches or passes through pelvic inlet.
Figure 15-7, p 314
The biparietal diameter (BPD) of fetal head settles into inlet of pelvis. In most instances, the occiput is at the level of the ishial spines () station.
Station –refers to the relationshio of presenting part to an imaginary line drawn between the ischial spines of the maternal pelvis. If the presenting part is higher than the ischial spines, the station has a negative #,  referring to centimeters above 0 station..Minus 5 is at the pelvic inlet.  Positive #s = presenting part has passed the ischial spines. Positive (+) 4 is at the outlet.
 See Figure 15-8,  p 315
Fetal position – relationship of the designated landmark of  fetal presenting part to the left or right side of the maternal pelvis. The designated landmarks are vertex: the occiput;  in face presentation: the mentum. In breech: the sacrum; for shoulder: the acromion process of the scapula. If directed to side, it is designated as transverse.
The landmark on the fetal presenting part  r/t four imaginary quadrants: left anterior, right anterior, left posterior, and right posterior, meaning: Is the presenting part directed toward the front, back, left or right of the passage?
 
Three notations:
1.Right ® or left (L) side of maternal pelvis
2.The landmark of fetal presenting part: occiput (O); mentum (M), sacrum (S), or acromion process (A).
3.Anterior (A), posterior (P), or transverse (T )
4. Figure 15-9 p 316.
Click back to slide 7
Power:  Primary forces:  is the uterine contraction → complete effacement and dilation of the cervix. Secondary forces: use of abdominal muscles to push during the 2nd stage of labor. Pushing force adds to the primary force after the cervix is fully dilated.
Contractions have a rhythmic pattern, with periods of  relaxation between, allowing the woman to rest. This resting period allows for restoration  of placental circulation: important to uterine muscles but also for the baby’s oxygenation. Increment: the building up and longest; acme – peak; and decrement or letting up. 
Characteristics: frequency: time between beginning of one contraction to the beginning of the next.  Duration: beginning to completion of a single contraction. Intensity – strength of contraction. Experienced nurse can estimate by palpating the fundus (top) during the contraction.  Mild: the uterine wall can be indented; strong, it cannot be indented.  Intensity can be measured directly with an intrauterine probe. 
Look at Figure 15-10, p 317
Power of forces
Transition to new role – couple; permanent change in lifestyle, relationships, & self-image.; differences between primi and multi: “losing it” – being out of control; fear of pain; birthing plan: will it be honored?
Most primigravidas and many multigravidas experience the following S & Sx of labor: Lightening – the fetus settles into pelvic outlet (review: engagement); leg cramps, ↑ pelvic pressure, leg edema, ↑ vaginal secretions Braxton Hicks contractions – (irregular, intermittent contractions or “Practice” throughout pregnancy, like menstrual cramps. Strong → woman in false labor
Cervical changes – rigid, firm cervix softens or “ripens”
Bloody show – mucus plug is expelled → exposed cervical capillaries  → pink-tinged secretions Rupture of membranes – ROM (not range of motion). 12% before labor begins. Then 80% go into labor within 24 hrs. Watch carefully: if fetus not engaged, cord can prolapse with fluid gush. Inc risk for infection
Sudden burst of energy – 24 – 48 hrs /a delivery
Other: weight loss 1-3 lbs, N&V, diarrhea
True Vs False labor: contractions of TRUE labor → progressive dilatation & effacement of cervix; regular & inc in frequency, duration, & intensity; pain starts in back & radiates to abdomen. Walking  intensifies pain.
False labor doesn’t; woman feels foolish (tell story of VICKY).
Table 15-4: Comparison of True & False, p 321
Four stages of labor:
First stage: the longest stage occurs between onset of true labor and the point of cervical dilation and effecement. Second stage is the expulsion of the fetus;  third stage – delivery of placenta; and fourth stage – 1st 4 hrs /p delivery of placenta
First stage: divided into 3 phases
•Latent – begins with onset of regular contractions, with contractions q 15 -20 min,  lasting 20 -30 secs, gradually lnc to  q 5 – 7 min, 30 – 40 secs duration. Little or no cervical dilation. Women stay home. Phase ends when cervix is 3 cm. Lasts 8.6 hrs for primi, < 6 for multi.
•Active phase – begins 4 cm, ends when dilated to 7cm; contractions 2 – 3 mins, 40 – 60 secs; cervix should dilate about 1 to 1.5 cm /hr.  Primi – avg 4.6 hrs, multi 2.4 hrs
•Transition phase – shortest, most intense. Dilation from 8 to 10 cm; contractions q 1.5 – 2 mins, lasting 60 – 90 secs (pain & rest about same). Lasts avg 3.6 hrs for Primi; varies with multi. Woman becomes restless, angry, wants to go home, wants a C-sec, N&V, etc. Withdraws from support (spouse, coach, etc), leaving partner feeling useless. NURSE IS VITAL at this point to both. NURSE must prepare for 2nd stage.
Second stage: cervix is completely dilated & effaced; known as pushing stage; up to 3 hrs for primi, < 30 mins in multi.  The woman bears down, abdominal muscles contract, & help fetal head descend. When fetal head is visible at vulvar opening, crowning has occurred and birth is imminent. Some women feel relief, birth is near; others feel frightened and overwhelmed. Pt can assume different positions. In US, lithotomy position  most common.
Positional changes of fetus: called cardinal movements:
1.Descent: progression of head into pelvis d/t pressure of amniotic fluid, the contracting uterus, the  effects of contractions on mother’s abdominal muscles and diaphragm, and the extension and straightening of the fetus. Head enters at an oblique or transverse position
2.Flexion – resistance from soft pelvic tissues → flexion  of chin against chest :: smallest fetal diameter
3.Internal rotation – fetal head must rotate to accommodate the pelvis; head rotates from left to right
4.Extension – fetal head pivots under symphysis pubis. Head emerges through extension, followed by occiput, then the face, and finally the chin
5.Restitution – internal rotation causes shoulders to enter pelvis in an oblique position and neck becomes twisted. When head is delivered, the neck untwists and aligns with long axis of fetus.
6.External rotation – shoulders rotate, turning head further to one side
7.Expulsion – anterior shoulder slips under symphysis pubis, followed by posterior shoulder. Once shoulders are delivered, the trunk follows. (Sometimes rather quickly!)
1.
Figure 15-13 (illustration), p 325
Birth sequence Figure 15 -12, p 324
Click back and forth
Third stage – begins as soon as baby delivered and lasts until placenta delivered. Combination of contractions and involution (growing smaller) .  Placenta detaches from wall within 10 – 15 mins → inc bleeding; delivery of placenta follows. Classic signs: uterus “rounds up” into ball, moves upward, the cord lengthens, followed by rush of vaginal blood. Once placenta delivered, contractions close off arterioles, uterus continues to shrink, & bleeding ↓.
Figure 15-14, p 326: “shiny” Shultze or “Dirty” Duncan
Fourth stage – “recovery stage” or 1st 4 hours /p delivery. Avg blood loss is 250 – 500ml;blood is redistributed in venous bed, → mod drop in BP, inc pulse pressure, and mod tachycardia. fundus is midline,
Maternal responses: during labor: with each contraction, 300-500 mls of blood forced into maternal circulation → ↑ cardiac out put which ↑ with pain and anxiety. In supine position,  cardiac output ↓, HR ↑, stroke volume↓. Best to assume side-lying position. BP ↑ during contractions and pushing.
Respiratory:  anxiety & pain → hyperventilation & respiratory alkalosis; muscular activity → mild metabolic acidosis. Acid-base balance  - norm /p 24 hrs
Renal & GI – ↑ in pressure and edema to bladder can lead to over distension; ↑ in renin &  angiotension help control uteroplacental blood flow. GI – gastric emptying delayed → risk of aspiration if general anesthesia necessary
Immune/blood – WBCs inc to 25,000 – 30,000. Blood glucose ↓ (energy during contractions), insulin requirements drop
Pain – gate-control theory: mechanism aloows  ↑ or↓ in impulses to CNS. Pain can be reduced through tactile stimulation such as back rubs, sacral pressure, effleurage;  and CNS-controlled activities such as suggestion, distractions, & conditioning.
Pain varies: 1st stage: stretching, pressure, hypoxia of muscles during contraction; 2nd stage – hypoxia to uterine muscles, stretching of vagina & perineum and pressure on adjoining . Figure 15 – 16, p 328.
What about fetal response? Heart rate changes in response to intracranial pressure from maternal contractions; fetal blood pressure protects fetus during contractions; fetus responds to light, sound, & touch, beg 37 wks
Determine if true or false labor:
True: contractions regular, becoming stronger, lower back radiating to abdomen, more intense with walking cervical changes, fetus moving to lower pelvis. False: irregular contractions which stop with walking, pain abdominal and stopping with comfort measures.
Data collection:
Review prenatal data for baseline information;
Identify expected problems such as bleeding, diabetes, screening results
Previous delivery info; check EDC
Interview: time of onset of regular contractions, frequency, pain level
Vaginal DC, characteristics, ROM, Nitrazine test of pH (ROM – alkaline), “Fern” test
Last PO intake’ Birth plan; childbirth prep, cultural considerations, support
Assessment: VS, Leopold’s Maneuvers for position of fetus Figure 16-5, p 343
Vaginal exam to gauge dilation – Figure 16-3 & 16-4, p 342
Fetal monitoring: auscultating through Doppler or fetoscope, after Leopold’s Maneuvers to determine position. FHR  most clearly heard at fetal back. Figure 16-6.
Electronic fetal monitoring produces continuous tracing. Can be external through US. A tranducer is placed on maternal abdomen. The transducer produces sound waves which bounce off  the fetal heart and picked up by electronic monitor. Differentiate between Maternal and fetal  HR.
Go to next slide.
Internal monitoring requires an internal spiral electrode.The membranes must be ruptured, the cervix dilated to 2 cm or >, the presenting part must be down against the cervix, and the examiner must recognize which fetal part is presenting  (to avoid injury). A sterile spiral electrode is inserted into vagina against presenting part, & rotated until it attaches. Provides accurate, continuous movement, with a clearer signal and minus interruptions d/t maternal or fetal movements.
Evaluations: Normal – 120 160 bpm. Variability is the change from baseline that occurs over seconds or minutes (the wiggles)
Abnormal variations are > 160 bpm (tachycardia) or < 120 bpm (bradycardia). Tachycardia is considered  (sustained rate of 161 bpm )  ominous if accompanied by late decelerations, severe variable decels, or ↓ variability.  Bradycardia  with rate < 110 – 120 bpm during a 10 min period can be ominous or benign. When accompanied by late decels, considered a sign of fetal distress.
Accelerations: the transient ↑ in FHR normally caused by fetal movement. In response to contractions, considered a good sign.
Decelerations: periodic decreases in FHR from norm baseline. Categorized  as early, late, and variable.
Early -  Fetal head is compressed → central vagal stimulation → early deceleration. Onset is before onset of uterine contraction, considered benign.
Late – caused by uteroplacental insufficiency d/t dec blood flow & O2  to fetus during contraction.  Occurs after onset of contractions. Considered non-reassuring, but not necessarily eminent for childbirth.
Variable – umbilical cord is compressed, ↓ blood flow between placenta & fetus. Needs further assessment.
Look on pate 349, Figure 16 – 11.
Keep watch on Mom’s contractions.
Keep vaginal exams to minimum to prevent infections. Figure 16-2, p 341
During prenatal visits, patient learns to come to birthing unit
1.ROM
2.Regular, frequent contractions (nullipara- 5 mins apart, multiparas – 10 – 15 mins apart x1hr
3.Vaginal bleeding.
Admission process influences the course of hospital stay. Refer to Teaching About… p 358
Nursing management:1st stage: 
Assist to bed; side-lying position; obtain admission data; collect clean ureing speciman; dipstick urine for presence of protein, glucose, ketones ; draw labs for Hct, Hgb, T&C, serological testing per institution policy; signed informed consent
Provide education
Family expectations – emotional support, comfort measures, advocacy for dreams for birth experience; praise for efforts.
Integration of cultural beliefs: knowledge of values, customs, and practices is vital in L&D. Modesty issues (males present, Asian cultures); Middle East countries
Pain expression: quiet or vocal; some “keen” and wail. Depends on culture. Concept of hot and cold  foods & water.
Pain: physiologic manifestations : ↑ pulse & resp; dilated pupils, ↑ BP, & muscle tension. Women often tighten skeletal muscles and lie motionless → muscular tension.
Latent: pt is usually happy & eager; establish rapport; offer fluids; comfort measures
Active :  feelings of helplessness, abandonment; enc maintaining breath patterns; comfort rubs, keep couple informed
Transition: restless, tired, irritable; feels out of control; enc her to rest between contractions; promote comfort; some women don’t want to be touched; ice chips, privacy
REFER TO TABLE 17-2: P 367
Stage 2: patient may feel helpless, panicky, out of control; assist in pushing efforts; encourage & praise; maintain privacy as woman desires
Until modern times, upright was the norm for giving birth. Maternal birthing positions: Sitting on birthing stool; squatting; hands & knees. Work with gravity. The recumbent position (lithotomy) became the norm d/t increased convenience of modern technology. 
Immediate care of Newborn: Airway umbilical cord, Apgar, warmth, identification. Apgar scores 0-2 for Heart rate, respiratory effort, muscle tone (look like a frog), reflex irritability, & color. For possible 10 pts. Scored at  at 1 & 5 mins.
While waiting for signs of placental delivery, palpate the uterus for signs of uterine relaxation & possible bleeding into uterine cavity. Oxytocics such as Pitocin are given to promote contractions, involution, & ↓ bleeding. Sometimes Methergine or Hemabate are given. After placenta delivered, physician or midwife inspect vagina & cervix and make necessary repairs. Episiotomy is repaired. Monitor uterine fundus firmness; vital signs: BP q  5 – 15 min (↑ - d/t preeclampsia or oxytocic drugs↓; temp –  reflect blood loss); dehydration and exhaustion; “shivers” ; inspect bloody vaginal discharge.
Transfer to PP if:
VS stable, no bleeding, undistended bladder, firm fundus, & recovery from anesthesia agents
See Figure 17-9 for method of palpating fundus.
Enhancing attachment: contact during 1st hour important; quiet state – baby will interact with parents; ideal time to breast feed (Swedish study); darken room if possible
Precipitous delivery: without physician or midwife;  precipitous labor defined as < 3 hrs, rapid birth