ch 16. labor & birth process

Question 1

The 5 P’s of pregnancy (5)

Answer 1

passageway (pelvis)
passenger (fetus): relationship of maternal pelvis -> presenting part
power: physiologic forces of labor
positioning (of mother)
psychosocial considerations

Question 2

birth passageway (what (3), soft tissues of (3), types (4)

Answer 2

1) true pelvis
- inlet
- midpelvis (pelvic cavity)
- outlet

2) soft tissues of cervix, vagina, pelvic floor

3) types of pelvises:
- gynecoid
- android
- anthropoid
- platypelloid

TIP:
+4 out the door

Question 3

inlet is also know as

Answer 3

linea terminalis

Question 4

gynecoid (2)

Answer 4

inlet ROUNDED with all inlet diameters adequate midpelvis diameters adequate with parallel side walls
- outlet adequate

implications: favorable for vaginal birth

Question 5

android (3, implications (3))

Answer 5

inlet HEART SHAPED with short posterior sagittal diameter
- midpelvis diameter reduced
- outlet capacity reduced

implications:
- NOT favorable for vaginal birth
- descent into pelvis slow
- fetal head enters pelvis in transverse or posterior position with arrest of labor frequent

Question 6

anthropoid (3, implications (1))

Answer 6

inlet OVAL in shape, with long anterioposterior diameter
- midpelvis diameters adequate
- outlet adequate

implications:
- favorable for vaginal birth

Question 7

platypelloid (3, implications (3))

Answer 7

inlet OVAL in shape, with long transverse diameters
- midpelvis diameters reduced
- outlet capacity inadequate

implications:
- fetal head engages in transverse position
- difficult descent through midpelvis
- frequent delay of progress at outlet of pelvis

Question 8

birth passenger (fetus) (4)

Answer 8

• head
• attitude
• lie
• presentation

Question 9

fetal head (2, key landmarks (4))

Answer 9

1) fetal skull
2) sutures: fontanelles (presentation determination)
3) key landmarks:
- mentum: fetal chin
- sinciput: anterior area known as the brow (brow -> anterior font.)
- vertex: area between anterior and posterior fontanelles (how baby presents)
- occiput: area of fetal skull occupied by the occipital bone, beneath the posterior fontanelle

Question 10

fetal attitude (3)

Answer 10

• relation of the fetal body parts to one another
• normal attitude: general flexion
• deviations contribute to longer, more difficult labor -> causes fetus to present larger diameters to the fetal head to the maternal pelvis

Question 11

fetal lie (3)

Answer 11

• relationship of the long, or cephalocaudal, axis (spinal column) of the fetus to the long, or cephalocaudal, axis of the mother
• longtitudinal lie: cephalocaudal axis of fetal spine is parallel to the mother’s spine (99.5% all births)
• transverse lie: cephalocaudal axis of fetal spine is at a right angle to the mother’s spine (shoulder presentation, cradle in mom’s pelvis)

Question 12

fetal lie complete breeched (attitude, presenting part, landmark)

Answer 12

• attitude: flexed hips/knees
• presenting part: buttocks
• landmark: sacrum

Question 13

fetal lie frank breeched (attitude, presenting part, landmark)

Answer 13

• attitude: flexed hips, extended knees with legs against abdomen and chest
• presenting part: buttocks
• landmark: sacrum

Question 14

fetal lie footling: single, double (attitude, presenting part, landmark)

Answer 14

• attitude: extended hips and atleast one knee extended with foot in cervical canal
• presenting part: buttocks
• landmark: sacrum

Question 15

fetal lie kneeling: single, double (attitude, presenting part, landmark)

Answer 15

• attitude: extended hips, flexed knees
• presenting part: feet (one or two)
• landmark: sacrum

Question 16

cephalic fetal presentation (4)

Answer 16

• vertex: when presenting part is the occiput
• sinciput: fetal head is partially flexed
• brow presentation: fetal head is partially extended
• face: fetal head is hyperextended

Question 17

breech fetal presentation (3)

Answer 17

• complete: knees and hips flexed, thighs are on the abdomen, calves are on the posterior aspect of the thighs
• flank: hips flexed, knees extended
• footling: hips and legs are extended

Question 18

relationship of maternal pelvis and presenting part (2 + fetal position (3)

Answer 18

1) engagement: presenting part thru pelvis inlet
2) station: ischial spines
3) fetal position (3 notations):
- right (R) or left (L) side of maternal pelvis
- landmark of fetal presenting part: occiput (O), mentum (M), sacrum (S), or acromion process (A)
- anterior (A), posterior (P), or tranverse (T), depending on whether the landmark is in the front, back, or side of the pelvis

TIP:
Right/Left occiput anterior (easiest)

Question 19

physiologic forces of labor: power (uterine contractions (7)

Answer 19

1) uterine contractions
- increment (mmuscle contracts and tightens)
- acme (peak contraction)
- decrement (release)
- frequency (begin of one contraction to begin of next)
- duration (begin at end of one contraction)
- intensity
- resting tone (need to have rest in between contraction)

Question 20

psychosocial considerations (6)

Answer 20

• readiness of birth and motherhood
• fears
• anxieties
• birth fantasies
• level of social support
• perception of birth experience may influence mothering behaviors

Question 21

positive birth experiences (12)

Answer 21

• motivation for the pregnancy
• attendance at childbirth education classes
• a sense of competence or mastery
• self confidence and self esteem
• positive relationship with mate
• maintaining control during labor
• support from mate or other person during labor
• not being left alone in labor
• trust in the medical/nursing staff
• having personal control of breathing patterns, comfort measures
• choosing a physician/certified nurse midwife who has a similar philosophy of care
• receiving clear information regarding procedures

Question 22

physiology of labor (3 hypothesis)

Answer 22

1) progesterone withdrawal hypothesis
- progesterone produed by the placenta relaxes uterine smooth muscle
- decrease in availability of progesterone to myometrial cells
- yet unknown antiprogestin

2) prostaglandins hypothesis
- prostaglandins known to induce labor? not sure why?

3) corticotropin releasing hormone hypothesis
- known to stimulate synthesis of prostaglandins

TIPS:
- progesterone maintains pregnancy
- decrease in progesterone allows for contractions to occur

Question 23

myometrial activity (2)

Answer 23

1) effacement (before dilatation)
- taking up of the internal os and the cervical canal into the uterine side walls
- thinning and shortening (pullback) of the cervix that occurs late in pregnancy or during labor (0-100%)

2) cervical dilatation
- process in which the cervical os and the cervical canal widen from less than 1 cm to approximately 10 cm, allowing the birth of the fetus

Question 24

dilation examples

Answer 24

1cm: cherrio
2cm: penny
3cm: banana
4cm: ritz cracler
5cm: babybel
6cm: cookie
7cm: can of pop
8cm: baseball
9cm: doughnut
10cm: bagel

Question 25

musculature changes in the pelvic floor (3)

Answer 25

• muscles in the pelvic floor draw the rectum and vagina upward and forward during each contraction
• pressure of fetal head thins out perineal structure from 5cm -> 1cm
• normal physiologic anesthesia is produced due to decreased blood supple to area

Question 26

premonitory signs of labor (7)

Answer 26

• lightening “baby drops”
• braxton hicks contractions
• cervical changes
• blood show: pink tinged mucous plug (release)
• rupture (release) of membranes
• sudden burst of energy (nesting, overcleaning)
• weight loss, N/V/D, indigestion

Question 27

true labor (7) vs. warm up contractions (6)

Answer 27

1) true labor:
- contractions at regular intervals
- intervals between contractions gradually shorten
- contractions increase in duration and intensity
- discomfort begins in back and radiates around to abdomen
- intensity usually increases with walking (no effect on false labor)
- cervical dilatation and effacement are progressive
- contractions do NOT decrease with rest or warm tub bath

2) false labor:
- contractions are irregular
- usually no change in contractions
- discomfort usually in abdomen
- walking has no effect on or lessens contractions
- no change in dilatation or effacement
- rest and warm tub baths lessen contractions

Question 28

stages of labor (4)

Answer 28

1) first stage: latent, active, transition (0-10cm)

2) second stage: resting, active (10cm - birth)

3) third stage: birth baby -> placenta (5-30 min)
- after birth of infant, uterus contacts firmly, decreased surface area of placental attachment
- placenta begins to separate: bleeding, membranes last to separate
- placental birth: shiny shultz (fetal side), dirty duncan (maternal side)

4) fourth stage: 1st hour after birth
- 1-4 hours after birth
- blood loss 250-500 mL vaginal birth
- uterus remains contracted
- mother is starving
- shaking chill (neurological response)
- hypotonic bladder (decreased tone + neural sensation)

TIPS:
first labor: lasts 16-18 hours
labor after that cuts in half
caesarean birth: loss 1 L blood, greater than 1L = hemorrhage

Question 29

signs of placental separation (4)

Answer 29

• globular shaped uterus
• rise of fundus of uterus in abdomen
• sudden gush of trickle of blood
• further protrusion of the umbilical cord out of the vagina

Question 30

maternal systemic response to labor (7)

Answer 30

1) cardiovascular: stressed by contacrtions and pain, anxiety
2) blood pressure: increases during contractions
3) fluid and electrolyte balance: diaphoresis
4) respiratory system: increased oxygen demand
5) renal system: polyuria
6) GI system: prolonged gastric emptying time
7) immune systemL increased WBC during labor -> 25,000/mm3 - 30,000/mm3

Question 31

fetal response to labor (5)

Answer 31

1) heart rate changes: early decelerations
2) acid base balance in labor: blood flow to fetus slowed during acme of contractions, can lead to slow decrease in fetal pH
3) hemodynamic changes: fetal BP protective mechanisms,
4) behavioral states: sleep and awake
5) fetal sensation: fetus experiences labor (pain, sleep-wake states, as early as 6 months, skin to skin contact can help with pain/comfort)