Lesson 1: Labor and Delivery

What is LABOR?

Labor is a series of events by which uterine contractions and abdominal pressure expel a fetus and a placenta from the uterus.

What are the theories of Labor?

1. Uterine Stretch Theory

2. Prostaglandin Theory

3. Oxytocin Theory

4. Progesterone-deprived Theory

5. Aging Placenta Theory

What are the 4 components of Labor?

1. PASSAGE

2. PASSENGER

3. POWERS

4. PSYCHE

2 components of PASSAGE?

Bony Passage:

• PELVIS

Soft Passages:

• CERVIX

• VAGINA

• PERINEUM

What are the 4 pelvic types:

1. GYNECOID

2. ANDROID

3. ANTHROPOID

4. PLATYPELLOID

What are the 3 planes of PELVIS?

1. PELVIC INLET

2. MIDPELVIS

3. PELVIC OUTLET

PELVIC INLET: Diameter? Landmarks?

1. ANTERIOPOSTERIOR DIAMETER

2. SYMPHISIS PUBIS

3. SACRAL PROMONTORY

What are the AP diameters of the pelvic inlet?

1. TRUE CONJUGATE

2. DIAGONAL CONJUGATE

3. OBTETRIC CONJUGATE

TRUE CONJUGATE: Landmarks? Measurements?

Upper border of symphisis pubis to sacral promontory.

11-11.5 cm

DIAGONAL CONJUGATE: Landmarks? Measurements?

• WIDEST AP DIAMETER

• Lower border of symphisis pubis to sacral promontory

• 12.5 cm or mpre

OBSTETRIC CONJUGATE: Landmarks? Measurement?

• Smallest, MOST IMPORTANT AP DIAMETER

• Inner surface of symphisis pubis to sacral promontory.

• Subtract 1.5-2 cm from DC

MIDPELVIS: Diameter? Landmarks?

• TRANSVERSE DIAMETER

• Distance between 2 ischial spines

PELVIC OUTLET: Landmarks?

• ISCHIAL TUBEROSITIES

• SUBPUBIC ANGLE = 90°

Who is the Passenger?

FETUS

8 cranial bones

• Frontal Bone

• 2 Parietal bones

• Occipital Bone

• Ethmoid bone

• Sphenoid bone

• 2 temporal bones

What are the main suture lines?

1. CORONAL

2. SAGITTAL

3. LAMBOID

What are the 2 fontanelles?

• ANTERIOR FONTANELLE

• POSTERIOR FONTANELLE

What is Vertex, Siciput, and Occiput?

Vertex - Space b/w 2 fontanelles

Siciput - Area over the frontal bone

Occiput - Area over the occipital bone

What are the diameters od fetal skull?

• Suboccipitobregmatic

• Occipitofrontal

• Occipitomental

• Biparietal

What is FLOATING ENGAGEMENT?

FLOATING - Fetal head is above pelvic inlet

ENGAGEMENT - The BPD of fetal head aligns with the AP diameter of pelvis.

What is Fetal Attitude?

Degree of flexion a fetus assumes during labor; Relation of fetal part to each other.

Types of Fetal Attitude

• Complete Flexion

• Moderate Flexion

• Partial Extension/Poor Flexion

• Complete Extension

What about fetal lie?

Relationship between the cephalocaudal axis of the fetal body and the cephalocaudal axis of a woman’s body.

Types of Fetal Lie

• Longitudinal Lie

• Transverse Lie

• Oblique Lie

Fetal Presentation?

Denotes the body part that will first contact the cervix or be born first; Combination of fetal lie and fetal attitude.

Types of Fetal Presentation:

• Cephalic

• Breech

• Shoulder

Fetal Position?

Relationship of the presenting part to a specific quadrant of a woman’s pelvis.

What is Power?

Force supplied by the fundus of uterus and implemented by uterine contractions.

Types of Power?

PRIMARY (uterine contraction) and SECONDARY POWER (mother’s voluntary pushing efforts)

3 Phases of Uterine Contraction? 3 descriptors?

Phases of Uterine Contraction:

• Increment

• Acme

• Decrement

3 Descriptors of Uterine Contraction:

• Intensity

• Duration

• Frequency

What is Intrapartum?

From the onset of true labor to expulsion of placenta.

Signs of Impending Labor

• Lightening

• Bloody show/Mucus plug

• Rupture of membranes

• Regular Uterine Contractions

Difference b/w False and True Labor?

Stages of Labor?

• Dilatation Stage

• Delivery Stage

• Placental stage

• Recovery Stage

Active vs Latent Labor?

7 Cardinal Movements of Labor

EDFIEEE

• Engagement

• Descent

• Flexion

• Internal Rotation

• Extension

• External Rotation

• Expulsion

Signs of Placental Seperation?

• Sudden gush of blood

• Uterus becomes globular and firmer

• Lengthening of the umbilical cord

• Rise of the uterus into the abdomen

2 Mechanisms of Placental Expulsion?

• SCHULTZE

• DUNCAN

How to write CTG interpretation?

1. Baseline FHR. Normal Range?

2. Variability (has 4 types)

3. Acceleration

4. Deceleration (has 4 types)

5. Uterine Contractions

6. Category