NCM 107 LECTURE presence can be assessed manually through

A.Y. 1st Semester 2022-2023 the cervix after the cervix has dilated
Lecturer: MS. Argie J. Cajipo, RN, MAN during labor.
 Palpating for them during a pelvic
examination helps to establish the position
PASSENGER of the fetal head and whether it is in a
 The passenger is the fetus. The body part favorable position for birth.
of the fetus that has the widest diameter
is the head, so this is the part least
likely to be able to pass through the
pelvic ring. Whether a fetal skull can pass
depends on both its structure (bones,
fontanelles, and suture lines) and its
alignment with the pelvis.
Structure of the Fetal Skull
 The cranium, the uppermost portion of the
skull, is composed of eight bones. The four
superior bones—the frontal (actually two
fused bones), the two parietal, and the
occipital—are the bones that are important Diameters of the Fetal Skull
in childbirth. The other four bones of the  The shape of a fetal skull causes it to be
skull (sphenoid, ethmoid, and two temporal wider in its anteroposterior diameter than
bones) lie at the base of the cranium so in its transverse diameter. To best fit
are of little significance in childbirth through the birth canal, a fetus must
because they are never presenting parts. present the smaller diameter (the
The chin, referred to by its Latin name transverse diameter) to the smaller
mentum, can be a presenting part. diameter of the maternal pelvis; otherwise,
 The bones of the skull meet at suture progress can be halted and birth may not be
lines. The sagittal suture joins the two accomplished.
parietal bones of the skull. The coronal  The diameter of the anteroposterior fetal
suture is the line of juncture of the skull depends on where the measurement is
frontal bones and the two parietal bones. taken. The narrowest diameter
The lambdoid suture is the line of juncture (approximately 9.5 cm) is from the inferior
of the occipital bone and the two parietal aspect of the occiput to the center of the
bones. The suture lines are important in anterior fontanelle (the
birth because, as membranous interspaces, suboccipitobregmatic diameter).
they allow the cranial bones to move and  The occipitofrontal diameter, measured from
overlap, molding or diminishing the size of the occipital prominence to the bridge of
the skull so that it can pass through the the nose, is approximately 12 cm. The
birth canal more readily. occipitomental diameter which is the widest
 Significant membrane-covered spaces called anteroposterior diameter (approximately
the fontanelles are found at the junction 13.5 cm), is measured from the posterior
of the main suture lines. The anterior fontanelle to the chin.
fontanelle (sometimes referred to as the  If a fetus presents the anteroposterior
bregma) lies at the junction of the coronal diameter of the skull (a measurement wider
and sagittal sutures. Because the frontal than the biparietal diameter) to the
bone consists of two fused bones, four anteroposterior diameter of the inlet,
bones (counting the two parietal bones) are engagement, or the settling of the fetal
actually involved at this junction so the head into the pelvis, may not occur. If the
anterior fontanelle is diamond shaped. Its fetus does not rotate so the
anteroposterior diameter measures anteroposterior diameter of the skull is
approximately 3 to 4 cm; its trans-verse presented to the transverse diameter of the
diameter, 2 to 3 cm. It closes when the outlet, arrest of progress may occur.
infant is 12 to 18 months of age.
 The posterior fontanelle lies at the
junction of the lambdoidal and sagittal
sutures. Because three bones—the two
parietal bones and the occipital bone—are
involved at this junction, the posterior
fontanelle is triangular shaped. It is
smaller than the anterior fontanelle,
measuring approximately 2 cm across its
widest part. Because of its small size, it
closes when an infant is about 2 months of
age.
 Fontanelle spaces compress during birth to
aid in molding of the fetal head. Their
1
  A fetus is in moderate flexion if the chin
Molding is not touching the chest but is in an
 is a change in the shape of the fetal skull alert or “military position”. This
produced by the force of uterine contractions position causes the next-widest
pressing the vertex of the head against the anteroposterior diameter, the occipital
not-yet-dilated cervix. Because the bones of frontal diameter, to present to the birth
the fetal skull are not yet completely canal. A fair number of fetuses assume a
ossified and therefore do not form a rigid military position during the early part of
structure, pressure causes them to overlap and labor. This does not usually interfere with
molds the head into a narrower and longer labor, because later mechanisms of labor
shape, a shape that facilitates passage (descent and flexion) force the fetal head
through the rigid pelvis. to fully flex.
 Molding is commonly seen in infants just after  A fetus in partial extension presents the
birth. “brow” of the head to the birth canal. If
a fetus is in complete extension, the back
CAPUT SUCCEDANEUM - is the swelling or edema of is arched, and the neck is extended,
the scalp in a newborn that appear as a lump on presenting the occipitomental diameter of
the head after childbirth. the head to the birth canal.
CAUSE: from external pressures on the baby’s head  This unusual position presents too wide a
during delivery. skull diameter to the birth canal for
PRIMARY SYMPTOMS: swollen, puffy area of the head normal birth. Such a position may occur if
under the skin of the scalp there is less than the normal amount of
amniotic fluid present (olighydramnios),
which does not allow a fetus adequate
movement. It also may reflect a neurologic
abnormality in the fetus causing
spasticity.

 Molding is recorded immediately beneath the

state of amniotic fluid or liquor. Engagement- refers to the settling of the
presenting part of a fetus far enough into the
pelvis to be at the level of the ischial spines, a
midpoint of the pelvis.

 Descent to this point means that the widest

Four ways of recording molding part of the fetus (the biparietal diameter
in a cephalic presentation; the
intertrochanteric diameter in a breech
presentation) has passed through the pelvis
inlet or the pelvic inlet has been proved
adequate for birth.
 The degree of engagement is assessed by
vaginal and cervical examination. A
Fetal Presentation and Position presenting part that is not engaged is said
 Attitude - describes the degree of flexion to be “floating.” One that is descending
a fetus assumes during labor or the but has not yet reached the ischial spines
relation of the fetal parts to each other is said to be “dipping.”
 A fetus in good attitude is in complete
flexion: the spinal column is bowed
forward, the head is flexed forward so much
that the chin touches the sternum, the arms
are flexed and folded on the chest, the
thighs are flexed onto the abdomen, and the
calves are pressed against the posterior
aspect of the thighs.
2
 breech, with the breech, or buttocks, as
the first portion to contact the cervix.

Types of Fetal Presentation

Fetal presentation denotes the body part that will
first contact the cervix or be born first. This is
determined by a combination of fetal lie and the
degree of fetal flexion (attitude).
1. Cephalic presentation - is the most
frequent type of presentation
- With this type of presentation, the fetal
head is the body part that will first contact the
cervix.

4 TYPES OF CEPHALIC PRESENTATION

Station - refers to the relationship of the 1. Vertex - is the ideal presenting part because
presenting part of a fetus to the level of the the skull bones are capable of effectively molding
ischial spines. to accommodate the cervix.
2. Brow - moderately extended head, with the brow
 At a 3 or 4 station, the presenting part is presenting
at the perineum and can be seen if the 3. Face - sharply extended fetal neck that the
vulva is separated (i.e., it is crowning). occiput and back come in contact and the face is
nearest the birth canal
MINUS STATIONS (-): Presenting part above the 4. Mentum
levels of the ischial spines  During labor, the area of the fetal skull
Station -1 : 1cm above the level of the ischial that contacts the cervix often becomes
spines edematous from the continued pressure
Station -2 : 2 cm above the level of the ischial against it. This edema is called a caput
spines succedaneum. In the newborn, the point of
Station -3 : 3 cm above the ischial spines presentation can be analyzed from the
PLUS STATIONS (+) : Presenting part below the location of the caput.
ischial spines
Station +1: 1 cm below the level of the ischial
spines
Station +2: 2 cm below the ischial spines
Station +3: 3 cm below the level of the ischial
spines

In station +3, the presenting part can be seen at

the perineum (Cunningham et al., 2001).
2. Breech presentation - means that either the
buttocks or the feet are the first body parts that
will
contact the cervix.
Three types of breech presentation
1. Complete
2. Frank
3. Footling

Lie - is the relationship between the long

(cephalocaudal) axis of the fetal body and the
long (cephalocaudal) axis of a woman’s body; in
other words, whether the fetus is lying in a
horizontal (transverse) or a vertical
(longitudinal)position.
 Longitudinal lies are further classified as
cephalic, which means the head will be the
first part to contact the cervix, or
3
  Rupture of uterus
 Hemorrhage & Shock
 Maternal death
FETAL
 Cord prolapse
 Hand prolapse
 Intrauterine Demise (IUD)
 Fetal distress
EXTERNAL CEPHALIC VERSION  Still birth
 Performed after 36 or 37 weeks of pregnancy TREATMENT
 Non-surgical method  CS should be performed in persistent
 Medicine is given to relax the uterus transverse lie
 Ultrasound is done before & after the ECV  Internal podalic version in delivery of the
to check baby’s heart beat and position second twin
 Success rate is 40% to 50%  External cephalic version may be tried in
 Procedure usually lasts for a few minutes selected cases before labor or early in
 ECV can be uncomfortable and painful at labor
times  In advanced labor or in case of ruptured
membranes CS is safer even in case of fetal
death.

3.Shoulder Presentation (Transverse Lie) - a fetus

lies horizontally in the pelvis so that the
longest fetal axis is perpendicular to that of the
mother. The presenting part is usually one of the
shoulders (acromion process), an iliac crest, a
hand, or an elbow.

CAUSES OF TRANSVERSE LIE

 relaxed abdominal walls from grand
multiparity, which allow the unsupported
uterus to fall forward.
 pelvic contraction, in which the horizontal
space is greater than the vertical space.
 Placenta previa - in which the placenta is
located low in the uterus, obscuring some
of the vertical space
 With a transverse lie, the usual contour of
the abdomen at term is distorted or is
fuller side to side rather than top to
bottom.
 If an infant is preterm and smaller than
usual, an attempt to turn the fetus to a
horizontal lie may be made.
POSITION
1. Dorsoanterior – which is common (60%). The
flexor surface of the fetus is better adapted to
the convexity of the maternal spine.
2. Dorsoposterior
3. Dorsosuperior
4. Dorso-inferior

DANGER OF TRANSVERSE LIE

MATERAL
 Prolong labor
 Obstructed labor
4