Intrapartum Flashcards
Station
relationship of the leading edge of the fetal presenting part to the ischial spines (in cm)
0 = the presenting part is at the level of the spines
-3, -2, -1 = the presenting part is # cm above the ischial spines
+3, +2, +1 = number of centimeters the presenting part is below the ischial spines
Dilation
cervical os dilation from 0 - 10 cm (fully dilated)
Effacement
0-100% (fully effaced, like paper)
When to do a sterile speculum exam before the SVE?
ROM suspected, frank bleeding, inspection for herpes lesions
Presenting Part
the anatomic part of the fetus that first descends into the pelvis
- Cephalic
- Breech
- Shoulder
- Face
Position
relationship between the denominator of the presenting part and the maternal pelvis
What is the denominator for cephalic presentation?
Occiput
What is the denominator for breech presentation
sacrum
What is the denominator for shoulder presentation?
scapula
What is the denominator for face presentation
mentum (chin)
What is clinical pelvimetry?
manual examination of the pelvis to determine adequacy of the pelvis - this is not evidence based
What 4 bones compose the pelvis?
Two innominate (pubic) bones - the symphysis pubis joins these two pubic bones
Sacrum
Coccyx
What is the true pelvis?
Birth canal
What are the 3 parts of the true pelvis?
inlet, midplane, outlet
What are the boundaries of the inlet?
posteriorly: sacral prominatory
laterally: the linea terminalis
Anteriorly: the upper margins of the pubic bones
What are the boundaries of the midplane?
Posteriorly: sacrum at the junction of the 4th and 5th sacral vertebrae
Laterally: ischial spines
Anteriorly: the inferior border of the symphysis pubis
What are the boundaries of the outlet?
Posterior: sacrococcygeal joint
Laterally: inner surface of the ischial tuberosities
Anteriorly: lower border of the symphysis pubis
What are the 4 pelvis types?
Gynecoid
Android
Anthropoid
Platypelloid
What are the characteristics of a gynecoid pelvis?
- round shaped
- Transverse diameter is only slightly longer than AP diameter
- Incidence: 50% white women
- excellent prognosis for vaginal birth
What are the characteristics of an android pelvis?
- heart or triangular-shaped pelvis
- Posterior pelvis is wider than anterior pelvis
- Poor prognosis for vaginal birth, many times requiring operative VB or c/s
What are the characteristics of the anthropoid pelvis?
- Oval-shaped
- AP diameter is longer than transverse diameter
- Incidence: 40.5% of non-white women
- Good prognosis of vaginal birth, higher incidence of OP
What are the characteristics of a platypelloid pelvis?
- flattened gynecoid-shaped pelvis
- Wide transverse diameter with very short AP diameter
- Incidence: 3%
- Poor prognosis for vaginal birth
What are the types of FHR monitoring (3) during labor?
- Continuous by EFM
- Continuous by internal fetal monitoring
- Intermittent monitoring
What is continuous EFM and what are the risks/benefits?
FHR is monitored by External fetal monitor (u/s piece and toco)
Benefits: determines FHR, assesses variability, determines presence or absence of periodic changes such as decels, tachycardia, bradycardia
Risks: no risks really, but disadvantages can include: limiting mobility, not getting into tub, perhaps increases unnecessary intervention while not improving outcomes in low risk pregnancies