Intapartum Assessment & Interventions Flashcards
Maternal Factors that may Trigger Labor
stretching -> release of prostaglandins
pressure on cervix -> release of oxytocin -> UC
estrogen increases
oxytocin and prostaglandins work together -> activating UC
Fetal Factors that may Trigger Labor
placental age
prostaglandins made by fetal membrane -> UC
fetal cortisol rises and acts on placenta to reduce progesterone that quiets uterus -> increases prostaglandins that stimulate UC
Premonitory Signs of Labor
lightening: descent of the fetus into the true pelvis (2wks before term in first pregnancies, during labor in subsequent pregnancies)
Braxton-Hicks contractions: irregular UC that coordinate the many muscle layers of the uterus preparing them for labor
Bloody show: blood tinged cervical mucus as the cervix is changing
Rupture of membranes (ROM): rupture more than hour before onset of contractions
*GBS-: can give them time after water breaks if they want to wait at home as long as fluid was clear (no meconium)
GBS+: pt needs to come to hospital so you can start with prophylactic antibiotics to treat before birth
Assessing for Rupture of Membranes (ROM)
- sterile speculum exam to assess for vaginal pooling
- nitrazine: paper turns blue/black when in contact w/ amniotic fluid
- ferning: sample of fluid is taken and allowed to dry on a microscope slide if it has amniotic fluid will exhibit ferning pattern
Factors Affecting Labor
5 Ps Power (the contraction) Passage (the pelvis) Passenger (the fetus) Psyche (the response of woman) Position (maternal postures and physical positions to facilitate labor
Powers
UC -> cervical dilation (opening) and effacement (thinning) in the first stage of labor
Passage
greatest determinant in vaginal delivery of a fetus
true pelvis (inlet, midpelvis, and outlet)
size and type of maternal pelvis
ability of cervix to dilate and efface
ability of vaginal canal to distend
Passenger
Fetus and its relationship to the passageway, includes:
- fetal skull
- fetal attitude (chin tucked preferred)
- fetal lie
- fetal presentation (cephalic is preferred)
- fetal position
- fetal size
Fetal Head
biparietal diameter: largest transverse measurement and an important indicator of head size
molding: overlapping bones that allow skull to pass through narrow parts of maternal pelvis
sutures: membranous joints uniting cranial bones, allow for molding, used to identify positioning of the fetal head during a vaginal exam
Fetal Head Landmarks
Sagittal suture
fontanelles (anterior, diamond shape is larger)
vertex: area between anterior and posterior fontanelles
occiput: occipital bone, beneath the posterior fontanelle
Fetal Attitude
relationship of fetal body parts to one another (flexion or extension)
normal attitude = general flexion
- head flexed, chin on chest
- arms crossed over chest
- legs flexed at knee, thighs on abdomen
Fetal Lie
relationship of long axis (spine) of fetus and long axis (spine) of mother or cephalocaudal axis
- longitudinal: vertical (parallel relationship)
- transverse: horizontal (perpendicular relationship) *cannot be delivered in this lie
- oblique: diagonal
Fetal Presentation
presenting part (part or pole that enters the pelvis first)
- cephalic ~95% of births
- breech
Relationship of Maternal Pelvis and Presenting Part
station: narrowest part of pelvis between ischial spines = 0 station
- presenting part moves from -5 to +5
engagement: largest diameter of presenting part through pelvic inlet (for vertex this is the biparietal diameter)
- floating
- dipping
Fetal Position
describe the fetal position is the relation of the denominator or reference point to the maternal pelvis
6 positions for each presentation (right and left anterior, posterior, and transverse)
1st letter = R or L of woman’s pelvis (which side fetal spine is on)
2nd letter = fetal part presenting (occiput, mentum, sacrum, acromion)
3rd letter = position that the above fetal part is facing (anterior, posterior, or transverse)
