1. Factors Affecting Labor and Delivery Process

1. FACTORS AFFECTING LABOR AND DELIVERY PROCESS

• LABOR– a coordinated sequence of involuntary uterine contractions that results in effacement and dilatation of the cervix and voluntary bearing down efforts that result in birth.
• The process of moving the fetus, placenta, and membranes out of the uterus and through the birth canal.
• DELIVERY-the actual expulsion of the products of conception (fetus and placenta).
• Uterus sinks downward and forward about 2 weeks before term, into the true pelvis.
• Low persistent backache or sacroiliac distress.
• Strong, frequent, but irregular contractions.
• Vaginal mucous increases.
• Weight loss, burst of energy, NVD.
FACTORS AFFECTING LABOR-the 5 Ps of Labor
• Passenger
• Passageway
• Powers
• Position
• Psychological response
PASSENGER-THE FETUS
Interacting considerations:
 size of fetal head
 fetal lie
 fetal attitude
 fetal presentation
 fetal position
FETAL LIE
 Relation of long axis of fetus to the long axis of mother
 Spine-to-spine
 Usually longitudinal/vertical
 Can be transverse, as in shoulder presentation
FETAL ATTITUDE
 Relationship of fetal body parts to one another.
 The fetus assumes a characteristic posture in utero partly because of growth and partly because of the way the fetus conforms to the shape of the uterine cavity.
 Usually a flexed attitude, chin on chest, arms and legs flexed, cord between arms and legs.
FETAL PRESENTATION
 What part “presents” first into the pelvic inlet and leads the way to delivery
 Cephalic [or “Vertex”] (head first)
 Breech (buttocks first)
 Shoulder (only in 1%)
 Presenting part is the part felt by an examining finger during a vag exam.

FETAL POSITION
 Relationship of the presenting part (occiput, sacrum, mentum, sinciput) to the four quadrants of the mother’s pelvis.
PASSAGEWAY
 “Birth Canal” – pelvis, soft tissues of the cervix, pelvic floor (muscles), vagina, introitus (opening).
 The size and