NORMAL LABOUR AND DELIVERY Part 01

THE FETUS Fetal Lie refers to the orientation of the long axis of the fetus with respect to  the long axis of the uterus ...

THE FETUS

Fetal Lie

1. refers to the orientation of the long axis of the fetus with respect to  the long axis of the uterus
   
   • longitudinal
   • transverse
   • oblique
2. transverse/oblique often due to uterine anomalies  (C-section if they don”t convert)

Fetal Presentation

1. refers to the fetal part presenting at pelvic outlet
   
   • breech (complete, frank, footling)
   • cephalic
     
     1. vertex
     2. brow
     3. face
     4. sinciput  ( Forehead and above it )
   • shoulder
2. compound (fetal extremity prolapses along with presenting part)
3. all except vertex considered malpresentations
   

Fetal Position

1. refers to position of fetal occiput in relation to maternal pelvis
   
   • occiput anterior (OA): commonest presentation (ìnormal")
   • occiput posterior (OP): most rotate spontaneously to OA : may cause prolonged second stage of labour
   • occiput transverse (OT): leads to arrest of dilatation
2. normally, fetal head enters maternal pelvis and engages in OT position  subsequently rotates to OA position or OP (in a small percentage of cases)

Attitude

• refers to flexion/extension of fetal head relative to shoulders
  
  1. brow presentation : head partially extended (requires C-section)
  2. face presentation: head fully extended (mentum posterior always requires C-section, mentum anterior will deliver vaginally)

Station

• defined by position of presenting part relative to ischial spines

@ ischial spines = station 0 = engaged

THE CERVIX

1. Dilatation


• latent phase: 0-3 cm
• active phase: 4-10 cm


2. Effacement :  thinning of the cervix (25%-50%-100%)
3. Consistency


• soft vs. hard position
• posterior vs. anterior


4. Application : contact between the cervix and presenting part