Module 4: Intrapartum

Intrapartum

An involuntary physiologic process whereby the contents of the gravid uterus are expelled through the birth canal into the external environment

1. Uterine Muscle Stretching

2. Pressure on the cervix

3. Oxytocin stimulation works together with prostaglandins

4. Changes in the ratio of estrogen to progesterone

5. Placental age

6. Rising fetal cortisol levels

7. Fetal membrane production of prostaglandin

Theories of why labor begins

1. Lightening

2. Slight loss of weight

3. Excess energy

4. Backache

5. Ripening of the cervix

6. Rupture of membranes

7. Show

8. Uterine contractions

Preparation for labor /Preliminary Signs of Labor (Sign or Symptom):

Lightening

Sinking of the fetal head into the true pelvis (Preparation for labor)

Slight loss of weight

As progesterone level falls, more fluid is excreted, slightly lowering body weight (Preparation for labor)

Excess energy

Burst of adrenaline to provide energy for labor (Preparation for labor)

Backache

Beginning but unrecognized uterine contractions (Preparation for labor)

Ripening of the cervix

Prostaglandins soften the cervix to allow for shortening and dilatation (Preparation for labor)

Rupture of membranes

Membranes have ruptured with release of amniotic fluid (Preparation for labor)

Show

Internal cervical mucus plug has been released (Preparation for labor)

Uterine contractions

True beginning of labor (Preparation for labor)

Preliminary Signs of Labor:

Lightening

Or descent of the fetal presenting part (usually the fetal head) into the pelvis

10 to 14

Primiparas — Occurs approximately __ days before labor begins.

on the day of labor or even after labor has begun.

Multiparas — It is not as dramatic and usually occurs _________

1. Shooting leg pains from the increased pressure on a sciatic nerve

2. Increased amounts of vaginal discharge

3. Urinary frequency from pressure on her bladder

As the fetus sinks lower into the pelvis, a woman may experience:

Slight Loss of Weight

Progesterone level falls, body fluid is more easily excreted from the body, lead to a weight loss between 1 and 3 lb

1 and 3

Progesterone level falls, body fluid is more easily excreted from the body, lead to a weight loss between ______lb

Increase in Energy

Boost in epinephrine release, initiated by a decrease in progesterone production by the placenta.

Backache

An intermittent _______ stronger than usual may be the first symptom a woman notices

Ripening of the Cervix

Internal sign seen only on pelvic examination.

earlobe

Throughout pregnancy, the cervix feels softer than usual to palpation, similar to the consistency of an __________ (Goodell's sign).

butter soft; forward

At term, the cervix becomes still softer (described as "_________"), and it tips _______.

Rupture of the Membranes

A sudden gush or as a scanty, slow seeping of clear fluid from the vagina.

settle snugly; cervical dilation; shortening labor.

Early rupture of the membranes can actually be advantageous as it can cause the fetal head to __________ into the pelvis, aiding ______and ________

1. Intrauterine infection

2. Prolapse of the umbilical cord

Risks are associated with ruptured membranes:

Show

As the cervix softens and ripens, the mucus plug that filled the cervical canal during pregnancy is expelled.

Show

The exposed cervical capillaries seep blood as a result of pressure exerted by the fetus

"show" or "bloody show."

This blood, mixed with mucus, takes on a pink tinge and is referred to as

back; abdomen

True labor contractions usually begin in the ______ and sweep forward across the _______

Uterine Contractions

Increase in frequency and intensity over a period of hours; Involuntary and come without warning

1. Starts to be irregular then becomes regular and predictable.

2. Pain starts at the lower back and sweeps around the abdomen

3. Pain continues on ambulation and at any level of activity

4. Progressive duration, frequency and intensitty

5. Progressive cervical effacement and dilatation

Signs of True Labor

1. Irregular and unpredictable 2.Confine at the lower abdomen and groin

2. Disappear with ambulation and sleep

3. No progressive increase of duration, frequency, and intensity of uterine contraction.

4. No progress of cervical effacement and dilatation

Signs of False Labor

1. Passage

2. Passenger

3. Power

4. Psyche

There are four integrated concepts that are involved in the success of labor and delivery, often referred to as the Components or 4 P's of Labor:

Passage

Refers to the route a fetus must travel from the uterus through the cervix and vagina to the external perineum

Pelvis

Serves to support and protect the reproductive organs. A bony ring formed by four united bones:

Coccyx Sacrum

Two innominate bones:

Ilium Ischium Pubis

Each Innominate bone is divided into three:

Coccyx

Is below the sacrum, composed of very small bones, fuse together.

Sacrum

Forms the upper posterior portion of the pelvic ring.

Sacral Prominence

A joint connected with the lower lumbar vertebrae which is the landmark to identify when securing pelvic measurements

sacrococcygeal joint

Between the coccyx and the sacrum is the joint called (

A. False pelvis B. True pelvis

The Pelvis is Further Divided:

A. False pelvis

the superior half

B. True pelvis

the inferior half

Inlet

It is where the fetus must first pass to be born vaginally.

Outlet

The inferior portion, bounded at the back by the coccyx, on the sides by ischial tuberosity, and in front by the inferior aspect of the symphysis pubis

Cavity

Is the space between the inlet and the outlet. It is not straight but curve.

1. The curve slows and control the speed of birth.

2. The snugness of the cavity compresses the chest of the fetus, as the fetus passes through.

Physiologic reasons for the design of cavity:

Passenger

Refers to the fetus

Cranium

The uppermost portion of the fetal skull, is composed of 8 bones

Frontal — Two fused bone anteriorly. Two Parietal One Occipital

9Other Inferior Bones: Sphenoid, Ethmoid, two temporal bones.)

Four Superior bones:

Sinciput

The area over the frontal bone

Occiput

Tthe area over the occipital bone

Suture lines

This is where the bones of the skull meet.

Sagittal suture

A membranous inter-space that joins the parietal bones

Coronal suture

The line of junction of the frontal bone and the two parietal bones.

Lambdoid suture

The line of junction of the occipital bone and the two parietal bones.

Fontanelles

The membranes that are found at the junction of the main suture line.

Anterior fontanelle

Also called "Bregma", lies in the junction of the coronal and sagittal sutures and in diamond shape. It measures 3-4 cm. (anterior-posterior), and 2-3 cm (transverse) in diameter.

Posterior fontanelle

Lies at the junction of the lambdoid and sagittal sutures. It measures 2 cm. across the widest part.

1. Compress during birth to aid in molding of the fetal head

2. Helps to establish the position of the fetal head and whether it is in a

3. Favorable position for birth.

Advantages of the Fontanelles:

Biparietal diameter / transverse diameter

smallest diameter; 9.25 cm. (Diameters of the Fetal Skull)

Suboccipitobregmatic diameter

Smallest anteroposterior diameter; app. 9.5 cm (Diameters of the Fetal Skull)

Occipitofrontal diamete

Approximately 12 cm. (Diameters of the Fetal Skull)

Occipitomental diamete

Widest anteroposterior diameter; approximately 13.5 cm (Diameters of the Fetal Skull)

Complete Flexion

Allows the smallest anteroposterior diameter of the head to enter the pelvis. (degree of flexion of the fetal head)

Moderate flexion

Causes a larger diameter to enter. (degree of flexion of the fetal head)

Poor flexion

Forces the largest diameter against the pelvic brim so the head is too large to enter the pelvis. (degree of flexion of the fetal head)

Molding

Is overlapping of skull bones along the suture lines, which causes a change in the shape of the fetal skull to one long and narrow (a shape that facilitates passage through the rigid pelvis)

Molding

Caused by the force of uterine contractions as the vertex of the head is pressed against the not yet dilated cervix

Molding

The overlapping that occurs in the sagittal suture line and, generally, the coronal suture line can be easily palpated on the newborn skull

Fetal Attitude

Describes the degree of flexion a fetus assumes during labor or the relation of the fetal parts to each other

1. Vertex (full flexion)

2. Sinciput (moderate flexion [military attitude])

3. Brow (partial extension)

4. Face (poor flexion, complete extension)

Fetal Attitude:

Vertex (full flexion)

The fetus presents the smallest anteroposterior diameter (suboccipitobregmatic) of the skull to the inlet in this good attitude (Fetal Attitude)

Sinciput (moderate flexion [military attitude])

The fetus is not as well flexed and presents the occipitofrontal diameter to the inlet (sinciput presentation). (Fetal Attitude)

Brow (partial extension)

The fetus in partial extension (Fetal Attitude)

Face (poor flexion, complete extension)

The fetus presents a wide (occipitomental) diameter (face presentation). (Fetal Attitude)

Fetal Lie

The relationship of the long (cephalocaudal) axis of the fetus to the long (cephalocaudal) axis of the woman's body.

Horizontal / Transverse Position Longitudinal / Vertical Position

Fetal Lie:

Cephalic Breech

Classification: (Fetal lie)

Cephalic

head is the presenting part (Vertex or Occiput, Brow and Face or mentum) (Fetal lie)

Breech

buttocks or feet are presented. [Complete, Frank, Footling (single or double)] (Fetal lie)

Fetal Presentation

Denotes the body part that will first contact the cervix or be born first

Fetal Presentation

Determined by the combination of fetal lie and the degree of fetal flexion (attitude).

Cephalic Presentation

The most frequent type of presentation, occurring as often as 96% of the time

Cephalic Presentation

Fetal head is the body part that first contacts the cervix

Cephalic Presentation

Types: vertex, brow, face, and mentum

Vertex

The head is sharply flexed, making the parietal bones or the space between the fontanelles (the vertex) the presenting part. This is the most common presentation and allows the suboccipitobregmatic diameter to present to the cervix (Cephalic Presentation)

Brow

Because the head is only moderately flexed, the _______ becomes the presenting part. (Cephalic Presentation)

Face

The fetus has extended the head to make the ______ the presenting part. From this position, extreme edema and distortion of the ______ may occur. (Cephalic Presentation)

Mentum

The fetus has completely hyperextended the head to present the ______, causing the presenting diameter (the occipitomental) to be so wide that vaginal birth may not be possible. (Cephalic Presentation)

Breech Presentation

The buttocks or the feet are the first body parts that will contact the cervix

Breech Presentation

Occur in approximately 4% of births

Breech Presentation

are affected by fetal attitude the same as vertex presentation

Complete

The fetus has the thighs tightly flexed on the abdomen; both the buttocks and the tightly flexed feet present to the cervix. (Breech Presentation)

Frank

Attitude is moderate because the hips are flexed, but the knees are extended to rest on the chest. The buttocks alone present to the cervix. (Breech Presentation)

Footling

Neither the thighs nor lower legs are flexed. If one foot presents, it is a single-____ breech; if both present, it is a double-____ breech. (Breech Presentation)

"transverse"

1. one of the shoulders (acromion process)

2. an iliac crest

3. a hand, or an elbow

presenting part: (Shoulder Presentation)