Normal Labor and Delivery n Labor the process

Normal Labor and Delivery 正常分娩

n Labor : the process by which contractions of uterus expel the fetus. n Delivery : receive the neonate

1. definition Term pregnancy: 37 -42 weeks from LMP n pre-term delivery (labor): 28 - <37 weeks of gestational age n post-term delivery: 42 weeks n Abortion : <28 week n 85% of women spontaneous labor and delivery between 37 -42 weeks n

2. The four factors for labor Force ( uterine contraction) n birth canal (bony canal) n fetus (lie, position , presentation, weight) n psychical-factors n

Contractions onset, frequency, duration, intensity n increase in frequency and duration n uterus can be felt to harden during contraction n lasting about 30 -45 seconds n interval between contractions to be 5 min’ n Intensity (slight, middle, heavy) n the pain of labor is a character

n Birth canal; Bony canal Soft tissue canal (lower part of uterus, cervix, vagina

Bony pelvis The planes of pelvis n inlet plane (promontory) n mid plane of pelvis (ischia spines) n outlet plane(two intersecting triangles) n n

n fetus (lie, position , presentation, weight) Long axis of mother n LOA n Head down n Estimation of fetal weight : 2500 g - <4000 g n

3. Mechanism of labor n The process of labor and delivery is marked by change in fetal position in relation to the maternal pelvis Engagement (BPD decent to a level below the pelvic inlet An occiput below the ischial spines is engaged) n Flexion n Decent n Internal rotation n Extension n External rotation n

4. Symptoms and signs of the onset of the labor Painful uterine contraction n a show n effacement and dilation of the cervix n rupture of membranes n

The show n The mucus plug is expelled from the cervix n mixing with a little blood the rupture of the membranes n at any time during labor effacement and dilation of the cervix n to be short, taken up, dilated

The differentiation of labor n in labor: spontaneous uterine contraction with progressive dilation of the cervix interval < 5 ’ lasting >30’’ intensity is middle or heavy n False labor:

5. Three Stages of labor The first stage: n onset of labor to full cervical dilation(10 cm) n the latent phase ( onest to <3 cm, <16 h) n the active phase(>3 cm to 10 cm, <8 h) The second stage: n 10 cm to the delivery of the infant, <2 h The third stage: n delivery of the infant to delivery of the placenta, <30 m’

6. Management of normal labor The first stage: n education, eating, walking, n position(sitting, reclining, recumbent) n monitoring of the fetal heart rate , n Palpation of cervix ( effacement , dilation) n uterus contractions (palpation or electronic monitoring) n Analgesia and anesthesia

The second stage fetal heart rate n maternal conditions: pulse, blood pressure, respiratory rate , temperature, urine output, fluid intake… n evaluation of progress of labor station, position of the presenting part, status of membranes, meconium, blood n

Pushing: n with the onset of each contraction, the mother is encouraged to inhale, hold her breath, and push n increase in intra-abdominal pressure n aiding in fetal descent through the birth cacal. n

Head visible on vulval gapping n Crowning of head n Laceration or Episiotomy n Delivery of fetus n Deal with umbilical cord n

the third stage: waiting for up to 30 min n Separation indication of placenta: the fundus changes to a globular shape and firm consistency A gush of blood appears vaginally The umbilical cord appears to lengthen n n delivery of placenta (spontaneously, manually inspection of the birth canal Repair of lacerations or episiotomy

Key word and questions Labor n Delivery n Engagement n Effacement n What are the four factors in labor and delivery? n What is the mechanisms of labor ? n Explain the separation indications of placenta. n