ch 13 Flashcards
(50 cards)
general flexion
- attitude
- back rounded
- chin flexed to chest
- thighs flexed on abdomen
- arms crossed over thorax
- UC between arms and legs
deviated attitude
- can cause difficulty in labor
- cephalic presentation with head flexed in a way that exceeds limits of pelvis can lead to c/s, prolonged labor, vacuum, forceps
biparietal diameter
- 9.25cm at term
- important indication of fetal size
- widest part of head entering pelvic inlet
- in complete flexion the diameter of head allows it to pass through canal
position
- reference point on the presenting part to the 4 quadrants of moms pelvis
- R or L
- A ,P, T
- presenting part (o,s,m,sc)
r or l
right or left side of mothers pelvis
apt
anterior, posterior, or transverse location of presenting part in relation to the mothers pelvis
presenting part
- occiptial (O), sacral (S), chin or mentum (M), scapula (SC)
- determined by lie,attitude, extension or flexion of head
station
- relationship or presenting fetal part to an imaginary line drawn between the maternal ischial spines and is a measure of the degree of descent of presenting part through birth canal
- placement of present in part is measure by cm below ischial spine
- -5-+5
- should be determined when labor begins to determine rate of descent
station 0
presenting part is at level of the spines and station is ____
station -1
lower most portion of presenting part 1 cm above spines
station +4 and +5
birth is imminent
vertex presentation
- head is in complete flexion
- this position allows easy passage through true pelvis
sinciput presentation
- moderate extension
- diameter widens making passage difficult
brow presentation
- marked extension or deflection so largest diameter
- to large to permit head to enter pelvis is presenting
primary powers
- Effacement
- Dilation
- Ferguson reflex
effacement
- shortening and thinning of the cervix during the first stage of labor
- only thin edge of cervix can be palpated when this is complete
- degree is in % from 0-100
dilation
- the enlargement or widening of cervical opening and canal that occurs once labor has begun
- diameter or cervix increases from less than 1cm to 10cm
- occurs by strong contractions
- pressure on amniotic fluid while membranes are still intact or force on the presenting part can promote this
- scarring of cervix from infection or surgery can slow this
full dilation
- cervix is completely retracted and cant be palpated
- marks the end of the first stage of labor
- 10 cm
- cranial bones over lap and membranes still intact
ferguson reflex
- in 1st and 2nd stage of labor increased intauterine pressure caused by contractions exerts pressure on the descending fetus and cervix
- when presenting part reaches perineal floor, mechanical stretching of cervix occurs
- stretch receptors cause release of oxytocin that triggers the maternal urge to bear down aka _______
uterine contractions
- independent of external forces
- may decrease in frequency and intensity temporarily if narcotics are given early in labor
- epidural
epidural
- lengthen the first and second stages of labor
- slows the rate of fetal descent
secondary powers
- Bearing-down efforts
- has no effect on dilation
- important in the expulsion of infant from uterus and vagina after cervix is fully dilated
bearing down efforts
- woman uses these to aid in expulsion of fetus as she contracts diaphragm and abd muscles and pushes
- these efforts result in increased intraabdominal pressure that compresses the uterus on all sides and adds the powers of expulsive forces
complete efacement
- 100%
- head is well applied to cervix