COMPONENTS OF LABOR

P’S IN LABOR & DELIVERY1. PASSAGEWAY

Woman’s pelvis and the birth canal2. PASSENGER

the fetus and placenta3. POWERS OF LABOR

force of uterine contractions4. POSITION OF THE MOTHER

5. PSYCHE/PSYCHOLOGIC RESPONSE of the mother

preserved so that afterward, labor can be viewed as a positive experience

1. PASSAGEWAY (BIRTH CANAL) THE PELVIS

FUNCTIONS OF FEMALE PELVIS allows movement of the body, especially

walking and running. permits the person to sit and kneel. adapted for child bearing, and because of

its increased width and rounded brim women are less speedy than men.

Pelvic bones

four pelvic bones Two

innominate( nameless) or hip bones

One sacrum One coccyx

Innominate bones:

1. Ilium2. Ischium3. Pubis

ILIUM the upper

flattened part of the hip bone

larger flared out part.

When the hand is placed on the hip it rests on the iliac crest, which is the upper border.

ISCHIUM thick lower part. has a large

prominence known as the ischium tuberosity, on which the body rests when sitting.

Behind and a little above the tuberosity is an inward projection, the ischial spine.

in labour the station of the fetal head is estimated in relation to the ischial spines.

PUBIS the anterior or front part

of the hip bone has a body and two oar

like projections, the superior ramus and the inferior ramus

The two pubic bones meet at the symphysis pubis and the two inferior rami from the pubic arch, merging into a similar ramus and the ischium.

The space enclosed by the body of the pubic bone, the rami and the ischium is called the OBTURATOR FORAMEN.

SACRUM a wedge shaped bone

consisting of five fused vertebrae

The upper border of the first sacral vertebra juts forward and is known as the sacral promontory

The anterior surface of the sacrum is concave and is referred to as the hollow of sacrum. Laterally the sacrum extends into a wing or ala.

COCCYX: a vestigial tail. A small bone

consists of four fused vertebra forming a small triangular bone.

During labor it moves backward, having more space for the delivery of the fetus this is called nodding.

Pelvic jointsThere are four

pelvic joints One symphysis

pubis Two sacroiliac

joints One sacro-

coccygeal joint

SYMPHYSIS PUBIS

formed at the junction of the two pubic bones, which are united by a pad of cartilage.

SACROILIAC JOINTS

these are the strongest joints in the body.

Joins the sacrum to the ilium and thus connect the spine to the pelvis.

SACRO COCCYGEAL JOINT

formed where the base of the coccyx articulate with the tip of the sacrum.

PELVIC BONE

Ligaments of the Pelvis

a short band of tough, flexible, fibrous connective tissue that connects two bones or cartilages or holds together a joint.

DIVISIONS OF THE PELVIS:FALSE PELVIS

superior half; upppet, larger but shallow division that supports the uterus in the abdominal cavity during pregnancy

divided by the linea terminalis into the false pelvis above this demarcation and the true pelvis below it.

the portion above the pelvic brim

TRUE PELVIS inferior half; lower, curved,

smaller portion constitutes the bony

passage /canal through which the fetus must pass through to be born vaginally.

L INEA TERMINALIS imaginary line that

separates the upper or false pelvis from the lower or true pelvis

DIVISIONS/PLANES OF THE PELVIS1. Pelvic Inlet

Upper portion;first pelvic plane; entrance to the true pelvis

Bounded by the upper border of the symphysis pubis,sacral promontory and linea terminalis

The anteroposterior(AP) points being the back side of the symphysis pubis and the sacral promontory, the smallest AP diameter called obstetrical Conjugate

2. Midpelvis(Pelvic Cavity) Between the boundaries for the

pelvic inlet and outlet The smallest diameter of the

midpelvis is the transverse or intraspinous diameter(between the 2 ischial spines)

3. Pelvic Outlet The plane of the pelvis that

lies at the level of the ischial tuberosities, the lower border of the symphysis pubis and coccyx

PELVIC DIAMETERS

1.Pelvic Inlet or Pelvic brim

Pelvic Inlet1. Palpation of pelvic brim:• The index & middle fingers are moved

along the pelvic brim.

IMPORTANT PELVIC

MEASUREMENTS AT 3 PLANES

1.Pelvic Inlet or Pelvic brim

DIAGONAL CONJUGATE (DC)

Widest anteroposterior diameter distance from the lower/ inferior

margin of the symphysis pubis to sacral promontory

measured by internal examination

ADEQUATE = 12.5 TO 13 CMS or more