Normal Labor and Delivery 正常分娩 林建华

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

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

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

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

正常曲线 异常曲线

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

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

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

3. Mechanism of labor 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) Flexion Decent Internal rotation Extension External rotation

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

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

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

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

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

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

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

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

the third stage: waiting for up to 30 min 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 delivery of placenta (spontaneously, manually inspection of the birth canal Repair of lacerations or episiotomy

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