Obstetrics

Fetal Sonographic Parameters

  • Crown-rump length (CRL)
  • Biparietal diameter (BPD)
  • Head circumference (HC)
  • Abdominal circumference (AC)
  • Femur length (FL)

Hormone Changes During Pregnancy

Item Hormones Sources
W Human chorionic gonadotropin (hCG) Placenta
  17-Hydroxyprogesterone Corpus luteum
X Human placental lactogen (hPL) Placenta
  Progesterone Corpus luteum
Placenta
  Estriol Placenta
Y Corticotropin-releasing hormone (CRH) Placenta

Stages of Labor

Stage Phase Events Primipara Multipara
1 Latent Effacement
Dilation: 0 → 6 cm
Engagement
Descent: high → 0
< 20 hours < 14 hours
  Active Dilation: 6 → 10 cm
Descent: 0 → +2
> 0.7 cm/h > 1 cm/h
2 - Expulsion :: fetus < 2 hours
< 3 hours if epidural
< 1 hours
< 2 hours if epidural
3 - Expulsion :: umbilical cord & placenta < 30 minutes < 30 minutes

Stages of Labor

Stage Phase Events Primipara Multipara
1 Latent Effacement
Dilation: 0 → 6 cm
Engagement
Descent: high → 0
< 20 hours < 14 hours
  Active Dilation: 6 → 10 cm
Descent: 0 → +2
> 0.7 cm/h > 1 cm/h
2 - Expulsion :: fetus < 2 hours
< 3 hours if epidural
< 1 hours
< 2 hours if epidural
3 - Expulsion :: umbilical cord & placenta < 30 minutes < 30 minutes

Bishop Score

  • Position
  • Consistency
  • Effacement
  • Dilation
  • Station

Factors Affecting the Duration of Labor {3P}

  • Passenger
  • Pelvis
  • Power

Passenger

  • Attitude: flexed & neutral & extended
  • Lie: longitudinal & oblique & transverse
  • Presentation
    • Cephalic: vertex [occiput] & sinciput & brow & face & chin
    • Breech: complete & incomplete & frank & footling
    • Shoulder: arm & shoulder & trunk
  • Positions
    • Anterior: right anterior & anterior & left anterior
    • Transverse: right transverse & left transverse
    • Posterior: right posterior & posterior & left posterior

Pelvis

Class Shape Ischial Spines Favorable Positions
Gynecoid Round Non-prominent All
Android Heart Prominent None
Anthropoid Vertical ellipse Prominent OA & OP
Platypelloid Horizontal ellipse Non-prominent Tranverse