Components of Labor - Intrapartal Care Flashcards
is composed of the bony pelvis and the soft
tissues of the cervix, vagina, and perineum.
PASSAGE
the fetus
PASSENGER
or the uterine contractions and the use of
abdominal muscles for the pushing stage
POWERS
psychological state of the laboring woman
PSYCHE o
the route a fetus must travel from
the uterus through the cervix and
vagina to the external perineum.
Passage
bony passage:
pelvis
soft passages
cervix, vagina,
perineum.
has no obstetrical significance
False Pelvis
Linea Terminalis
Inlet
Where fetus must pass int he birth process
True Pelvis
(Inlet)well-rounded forward
& backward; wide pubic
arch; “female pelvis”
Gynecoid
The pubic arch forms an
acute angle ; lower pelvic
dimensions extremely
narrow; “male pelvis”
Android
smoothly curved oval inlet,
but AP diameter is shallow;
“flattened” pelvis
Platypelloid
Narrow transverse diameter
-AP diameter of inlet is
larger than d usual;
“ape-like” pelvis
Anthropoid
Distance between upper (superior) border
of the symphysis pubis to sacral
promontory
Adequate size: 11-11.5 cm
True Conjugate
Widest AP diameter at outlet
Distance from the lower (inferior) margin
of the symphysis to the sacral promontory
Adequate size: 12.5 cm or more
Diagonal Conjugate
Smallest AP diameter of the pelvic inlet
through which the head must pass
* Distance between the inner surface of the
symphysis pubis to sacral promontory
* To estimate: subtract 1.5 to 2 cm from the DC
Obstetric Conjugate
Smallest diameter of
midpelvis
Distance between the 2
ischial spines identified
through palpation during
Internal Examination (IE)
Curved sacrum at midpelvis
allows more room for
presenting part
Transverse diameter:
Smallest measurement in the distance
between the 2 ischial tuberosities
The narrowest transverse diameter of
the pelvic outlet though which the
widest diameter of the fetal head
(biparietal diameter) must pass
through
PELVIC OUTLET
The ____ effaces
and dilates sufficiently
to allow the first fetal
portion to descend
into the vagina
cervix
The ___ ___
(muscular layer)
helps the fetus rotate
anteriorly as it passes
through the birth
canal.
pelvic floor
The ___ _____
participates in
childbirth via passive
distention.
vaginal canal
widest diameter
Fetal head
A ________ soft
membranous gaps
(sutures) between the
cranial bones.
fontanel
the overlapping
of skull bones along the
suture lines; cause a
change in the shape of the
fetal skull to one long and
narrow (that facilitate
passage to the rigid pelvis).
Molding
To fit through the inlet of the birth canal best, a fetus must present the smallest diameter (the
transversediameter) of the head to the smallest diameter of the maternal pelvis (diagonal conjugate).
DIAMETERS OF THE FETAL SKULL
The smallest AP diameter;
measurement (approximately 9.5
cm); measured from the inferior
aspect of the occiput to the center
of the anterior fontanel
Suboccipitobregmatic
Measured from the occipital
prominence to the bridge of
the nose, is approximately 12
cm.
Occipitofrontal Diameter
The widest AP diameter
(approximately 13.5 cm);
measured from the posterior
fontanel to the chin
Occipitomental Diameter
(Transverse
Diameter) The
smallest diameter
of the fetal head
which measures
about 9.25 cm.
Biparietal
Diameter
The narrowest
diameter at the
pelvic inlet; a space
approximately 11
cm wide.
Anteroposterior
Diameter
The best presentation for birth is when the
fetus presents
a Biparietal Diameter to AP Diameter of pelvis.
At the _____, If a fetus presents one of the AP
diameters of the skull to the AP diameter of the
inlet, ENGAGEMENT, into the pelvis, may oc
Inlet
At the _____, the fetus must rotate to present this narrowest fetal head diameter (BD*) to the
maternal Transverse diameter, a space, approximately 11 cm wide
Outlet
