Components of Labor
Components of Labor *The 4 P’s:
• passage
• passenger
• powers
• psyche
i. PASSAGE
• refers to pelvis & soft tissues which include: lower uterine segment, cervix, vaginal canal
• 2 pelvic measurements --Necessary to determine adequacy:
diagonal conjugate- narrowest at inlet;
transverse diameter- narrowest at outlet
• If disproportion occurs usually the pelvis (If fetus presents in unusual position); could be R/t mother:
being < 4’9” tall
being < 18 years old
Underwent pelvic dislocation
• 4 main pelvic types:
1. Gynecoid – round, wide, deeper most suitable (normal female pelvis) for pregnancy
2. Android – heart shape “male pelvis”- anterior part pointed, posterior part shallow
3. Anthropoid – oval, ape like pelvis, oval shape, AP diameter wider transverse narrow
4. Platypelloid – flat AP diameter – narrow, transverse – wider
ii. PASSENGER
• Passage of fetal head
• Fetal skull composed of:
8 bones - 2 frontal bones fused; 2 parietal bones; 2 occipital bones; 2 temporal bones. && Where these bones meet become the
Suture lines - Sagittal- separates parietal bones; Coronal- separates frontal and parietal; lamboid - separates parietal and occipital. && These suture lines allow for overlapping of bones during delivery
Fontanels - anterior (diamond shape); posterior- (triangle)
• Smallest diameter-- Smallest diameter is the SUBOCCIPITOBREGMATIC – This area must present to pelvic inlet. ----this is the part you want presenting to pelvis
• Engagement- presenting part that enters the pelvis reaches the level of the ischial spines
• Molding-- change shape of head produced by force of contractions against cervix- TEMPORARY
Definitions
• Fetal attitude- degree of flexion the fetus assumes or relation of the fetal parts to one another: ][ (relationship of fetal parts to one another)
complete flexion
moderate flexion
partial flexion
• station- relation of presenting part to the level of
• passage
• passenger
• powers
• psyche
i. PASSAGE
• refers to pelvis & soft tissues which include: lower uterine segment, cervix, vaginal canal
• 2 pelvic measurements --Necessary to determine adequacy:
diagonal conjugate- narrowest at inlet;
transverse diameter- narrowest at outlet
• If disproportion occurs usually the pelvis (If fetus presents in unusual position); could be R/t mother:
being < 4’9” tall
being < 18 years old
Underwent pelvic dislocation
• 4 main pelvic types:
1. Gynecoid – round, wide, deeper most suitable (normal female pelvis) for pregnancy
2. Android – heart shape “male pelvis”- anterior part pointed, posterior part shallow
3. Anthropoid – oval, ape like pelvis, oval shape, AP diameter wider transverse narrow
4. Platypelloid – flat AP diameter – narrow, transverse – wider
ii. PASSENGER
• Passage of fetal head
• Fetal skull composed of:
8 bones - 2 frontal bones fused; 2 parietal bones; 2 occipital bones; 2 temporal bones. && Where these bones meet become the
Suture lines - Sagittal- separates parietal bones; Coronal- separates frontal and parietal; lamboid - separates parietal and occipital. && These suture lines allow for overlapping of bones during delivery
Fontanels - anterior (diamond shape); posterior- (triangle)
• Smallest diameter-- Smallest diameter is the SUBOCCIPITOBREGMATIC – This area must present to pelvic inlet. ----this is the part you want presenting to pelvis
• Engagement- presenting part that enters the pelvis reaches the level of the ischial spines
• Molding-- change shape of head produced by force of contractions against cervix- TEMPORARY
Definitions
• Fetal attitude- degree of flexion the fetus assumes or relation of the fetal parts to one another: ][ (relationship of fetal parts to one another)
complete flexion
moderate flexion
partial flexion
• station- relation of presenting part to the level of
Bibliography: “Components of Labor.” [Online] Available http://www.scribd.com/doc/27402513/birth-process-labor-and-delivery, May 13, 2011