PROBLEM WITH PASSAGEWAY

1. anterior-posterior (true conjugate)

2. diagonal conjugate

3. obstetric conjugate

4. transverse diameter

4 diameter of pelvic inlet

anterior posterior (true conjugate)

from the SACRAL PROMONTORY to SUPERIOR MARGIN OF PUBIC SYMPHISIS

1. diagonal conjugate

SACRAL PROMONTORY to INFERIOR MARGIN OF THE PUBIC SYMPHISIS

obstetric conjugate

SACRAL PROMONTORY to nearest point on POSTERIOR SURFACE OF SYMPHISIS PUBIS

1. transverse diameter

the widest distance across pelvic brim

transverse diameter

largest diameter of pelvic inlet

fetal station

rs of fetal head to mother’s pelvis

ischial spine and biparietal diameter

station 0 =

CEPHALOPELVIC DISPROPORTION (CPD)

A disproportion between the size of the fetal

head and the pelvic diameters, which results

in failure to progress in labor

before week 24

when should primi have their pelvic measurements done/

1. large baby

2. AB fetal position

3. Small pelvis

4. AB shaped pelvis

causes of CPS (4)

1. hereditary

2. diabetes

3. Post-maturity (still pregnant after due date has passed)

4. Multiparity (not the first pregnancy)

large baby due to (4)

INLET CONTRACTION

Narrowing of AP diameter of pelvis to less than 11 cm or

transverse diameter to 12 cm or less

11

12

inlet contraction

AP DIAMETER =

TRANSVERSE =

o Rickets in early life (lack in Calcium)

o Inherited small pelvis

INLET CONTRACTION Causes: (2)

o No engagement of presenting part

o But in multigravida, engagement does not occur until

labor begins

INLET CONTRACTION Symptom (2)

OUTLET CONTRACTION

Narrowing of transverse diameter (distance

between the ischial tuberosities at the outlet) to

less than 11 cm

11

OUTLET CONTRACTION

transverse d =

o sonogram during pregnancy

o Manually at prenatal visit or beginning of labor

OUTLET CONTRACTION measurement (2)

§ Large baby or small pelvis

§ Usually diagnosed when there is an arrest in descent

§ Station remains the same

Outlet contraction Assessment(3)

TRIAL LABOR

When woman has borderline (adequate) inlet

measurement and fetal lie and position are good

TRIAL LABOR

Continues as long as descent of the presenting

part and dilatation of the cervix continues to

occur

1. Inlet measurement

2. fetal lie

3. position

TRIAL LABOR

When woman has borderline (adequate)____ and ____ and ___ are good

1. descent of the presenting part continues to occur

2. dilation of cx continues to occur

TRIAL LABOR continues as long as (2)

SHOULDER DYSTOCIA

Fetal head is born but the shoulders are broad

§ prolonged second stage of labor

§ arrest of descent

§ retraction of fetal head with every uterine

contraction (turtle sign)

SHOULDER DYSTOCIA is suspected earlier if there is (3)

(turtle sign)

retraction of fetal head with every uterine

contraction

1. umbilical cord entrapment

2. inability of baby’s chest to expand properly

3. severe brain damage or death due to hypoxia or acidosis if delay in delivery

4. brachial plexus injury

dangers of shoulder dystocia (4)

1. external cephalic version

2. forceps birth

3. vacuum extraction

DIFFERENT TECHNIQUES USED TO

AID IN FETAL DELIVERY (3)

EXTERNAL CEPHALIC VERSION

Turning of a fetus from a breech to a cephalic position

before birth

EXTERNAL CEPHALIC VERSION

Maybe done as early as 34 to 35 weeks but the usual

time is 37 to 38 weeks

EXTERNAL CEPHALIC VERSION

Not always successful but can decrease number of CS

births

EXTERNAL CEPHALIC VERSION

Woman may feel uncomfortable because of the

pressure

37-38weeks

usual time for external cephalic version

34 to 35 weeks

external cephalic may be done as early as

§ FHR and ultrasound are recorded continuously

§ Tocolytics are used to relax uterus

§ The breech and vertex of the fetus are located and

grasped trans abdominally

§ Gentle pressure is then exerted to rotate the fetus in cephalic lie

ECV procedure (4)

Tocolytics

in ECV, __ is used to relax the uterus

1. FHR

2. ultrasound

(2) recorded continuously in ECV

1. breech

2. vertex

3. transabodominally

The (2) of the fetus are located and

grasped_____

ECV

FHR and ultrasound are recorded continuously

ECV

Tocolytics are used to relax uterus

ECV

§ The breech and vertex of the fetus are located and

grasped trans abdominally by the examiner’s hands

on the woman’s abdomen

ECV

§ Gentle pressure is then exerted to rotate the fetus in

forward direction to a cephalic

1. baby in breech

2. physician will feel the head and rump of baby externally

3. turn the baby by applying pressure externally

4. baby in cephalic posi, engaged in pelvis,, ready fo vaginal exam

ECV process

neuraxial analgesia

§ Administration of ______ significantly

increases the success rate of external cephalic

version among women with malpresentation at

term or late preterm, which then significantly

increases the incidence of vaginal delivery.

o Reversion

o Abruption

o Cord compression

o Rupture of membrane

o Onset of labor

o Non-reassuring fetal status

ECV risk (6)

o Multiple gestation

o Severe oligohydramnios

o Ruptured membranes

o Small pelvic diameters

o A cord that wraps around the fetal neck

o Unexplained third-trimester bleeding (placenta previa)

o Hyper extended fetal head

o Significant fetal or uterine anomaly

ECV Contraindications: (8)

FORCEPS BIRTH

Use of obstetrical forcep

FORCEPS BIRTH

Steel instruments

constructed of two

blades that slide

together at their

shaft to form a

handle

obstetrical forcep

forcep birth uses

1. One blade is slipped into the woman’s vagina next to the fetal head

2. The other is slipped into place on the other side of the head

3. The shafts of the instrument are brought together in the midline to form the handle

4. Apply pressure on the handle to manually extract the fetus from birth canal

forceps birth process (4)

FORCEPS BIRTH

In the past, routinely used but today rarely used

4% to 8%

percentage of how many times forceps birth are used TODAY

Rectal sphincter tears

FORCEPS BIRTH can lead to

1. dyspareunia (painful intercourse)

2. Anal incontinence

3. Increased urinary stress incontinence

Rectal sphincter tears can lead to (3)

dyspareunia

painful intercourse

o A woman is unable to push with contractions inn the

pelvic division of labor (regional anesthesia or spinal cord injury)

o Cessation of descent in the second stage of labor

o A fetus in abnormal position

o A fetus in distress from complication (prolapsed cord)

FORCEPS BIRTH

§ Necessary for the following conditions (4)

o Membranes must be ruptured

o CPD must not be present

o Fully dilated cervix

o Woman’s bladder is empty

§ Before forceps are applied (4)

record FHR

§ Nursing interventions for FORCEPS

before forceps application

1. Assess again FHR

2. Assess cervix for lacerations

3. Record time and amount of first voiding (rule out bladder

injury)

4/ Assess newborn for facial palsy or transient erythematous

mark on the check (will fade 1-2 days with no long-term

effects

Nursing interventions for FORCEPS

AFTER forceps application (4)

VACUUM EXTRACTION

With the fetal head at the perineum, a soft disk-

shaped cup is pressed against the fetal scalp and

over posterior fontanelle

VACUUM EXTRACTION

When vacuum pressure is applied, air beneath the cup is suctioned out and the cup then adheres so tightly to the fetal scalp that traction on the vacuum cord leading to the cup extracts the

Little anesthesia is necessary

VACUUM EXTRACTION

§ Advantages over forceps delivery:

o More perineal laceration

o Marked caput on the newborn head maybe

noticeable as long as 7 days after birth

o Tentorial tears from extreme pressure

VACUUM EXTRACTION

§ Disadvantages (3)

o If fetal scalp blood sampling was used

(suction can cause severe bleeding at the

sampling site)

o Preterm infants (softness of preterm skull)

VACUUM EXTRACTION

§ When to not used (2)