NM704 EXAM 1
What is the true pelvis vs the false pelvis?
-true pelvis is the clinically significant portion of the pelvis that the fetus must be
able to pass through and is much smaller than the perception of the false pelvis
What is the inlet? How does the fetus negotiate this during labor?
-upper entry into the true pelvis
-defined by sacral promontory around to the superior posterior pubis symphysis
-the fetus passes through this part of the pelvis with the biparietal diameter (the
largest transverse diameter of the fetal head) aligned with the long AP diameter
of the inlet
-asynclitism may present a smaller diameter--this is normal
What is the midplane? How does the fetus negotiate this during labor?
-the plane of least dimensions
-defined by S4 to ischial spines to the bottom of the symphysis pubis
-the fetus passes through this part of the pelvis by flexion to present the
suboccipitobregmatic diameter (smaller than BPD) & internal rotation to align the
AP diameter of the fetal head with the long AP diameter of the pelvis
What is the outlet? How does the fetus negotiate this during labor?
-defined by S5 to ischial tuberosities to the bottom of the symphysis pubis
,-the fetus passes through this part of the pelvis by extending the head in order to
negotiate the curve of carus
What is important to remember about the pelvic types?
-most women have a "mixture" of the different pelvic types
Gynecoid pelvis:
-inlet is rounded
-inlet transverse diameter is slightly longer than AP diameter
-outlet AP diameter is long
-inlet, mid-plane, and outlet diameters adequate
-prognosis for vaginal delivery is good
Android pelvis:
-inlet is heart-shaped
-inlet adequate
-mid-plane is reduced in both diameters
-outlet AP diameter is short and transverse diameter narrow
-prognosis for a vaginal delivery poor
Anthropoid pelvis:
-inlet is oval-shaped in the AP
-inlet AP diameter is long and transverse diameter short but adequate
-mid-plane AP diameter is long and transverse diameter adequate
-outlet AP diameter is long and transverse diameter adequate
, -prognosis for a vaginal delivery is good
Platypelloid pelvis:
-inlet is flat --transverse oval
-inlet AP diameter short and transverse diameter long
-mid-plane AP diameter short and transverse diameter wide
-outlet AP diameter short and inadequate and transverse diameter wide
-prognosis for a vaginal delivery is poor
What is fetal lie?
-relationship of the long axis of the fetus to the long axis of the mother
-longitudinal, transverse, oblique
What is fetal presentation?
-part of the fetus that presents first to maternal pelvis
-cephalic, shoulder, breech
What are the three things that impact the outcomes of home births?
-qualifications of birth attendants
-integration into maternity system for safe transfers
-appropriate criteria to determine eligibility
What is the true pelvis vs the false pelvis?
-true pelvis is the clinically significant portion of the pelvis that the fetus must be
able to pass through and is much smaller than the perception of the false pelvis
What is the inlet? How does the fetus negotiate this during labor?
-upper entry into the true pelvis
-defined by sacral promontory around to the superior posterior pubis symphysis
-the fetus passes through this part of the pelvis with the biparietal diameter (the
largest transverse diameter of the fetal head) aligned with the long AP diameter
of the inlet
-asynclitism may present a smaller diameter--this is normal
What is the midplane? How does the fetus negotiate this during labor?
-the plane of least dimensions
-defined by S4 to ischial spines to the bottom of the symphysis pubis
-the fetus passes through this part of the pelvis by flexion to present the
suboccipitobregmatic diameter (smaller than BPD) & internal rotation to align the
AP diameter of the fetal head with the long AP diameter of the pelvis
What is the outlet? How does the fetus negotiate this during labor?
-defined by S5 to ischial tuberosities to the bottom of the symphysis pubis
,-the fetus passes through this part of the pelvis by extending the head in order to
negotiate the curve of carus
What is important to remember about the pelvic types?
-most women have a "mixture" of the different pelvic types
Gynecoid pelvis:
-inlet is rounded
-inlet transverse diameter is slightly longer than AP diameter
-outlet AP diameter is long
-inlet, mid-plane, and outlet diameters adequate
-prognosis for vaginal delivery is good
Android pelvis:
-inlet is heart-shaped
-inlet adequate
-mid-plane is reduced in both diameters
-outlet AP diameter is short and transverse diameter narrow
-prognosis for a vaginal delivery poor
Anthropoid pelvis:
-inlet is oval-shaped in the AP
-inlet AP diameter is long and transverse diameter short but adequate
-mid-plane AP diameter is long and transverse diameter adequate
-outlet AP diameter is long and transverse diameter adequate
, -prognosis for a vaginal delivery is good
Platypelloid pelvis:
-inlet is flat --transverse oval
-inlet AP diameter short and transverse diameter long
-mid-plane AP diameter short and transverse diameter wide
-outlet AP diameter short and inadequate and transverse diameter wide
-prognosis for a vaginal delivery is poor
What is fetal lie?
-relationship of the long axis of the fetus to the long axis of the mother
-longitudinal, transverse, oblique
What is fetal presentation?
-part of the fetus that presents first to maternal pelvis
-cephalic, shoulder, breech
What are the three things that impact the outcomes of home births?
-qualifications of birth attendants
-integration into maternity system for safe transfers
-appropriate criteria to determine eligibility
