• Birth canal
• Fetus
• Birth force

Birth canal

• Hard birth canal – bony pelvis
• Soft birth canal – muscles, ligaments, fascia and pelvic floor

Hard birth canal

• Bony pelvis
  • Great
  • Lesser

• Distantia bispinalis 25-26 cm
• Distantia bicristalis 28-29 cm
• Distantia bitrochanterica 31-32 cm
• Conjugata externa 18-20 cm

• Pelvic inlet
  • Anteroposterior 11 cm
  • Transverse diameter 13 cm
  • Oblique diameter 12 cm
• Pelvic width
  • Anteroposterior 12 cm
  • Transverse diameter 12 cm
• Pelvic isthmus 
  • Anteroposterior 11 cm
  • Transverse diameter 10,5 cm
• Pelvic outlet
  • Anteroposterior 9,5 cm, after retraction of the coccyx 11-11,5 cm
  • Transverse diameter 11 cm

    

Soft birth canal – pelvic floor

• Pelvic diaphragm 
• Urogenital diaphragm

  

Birth force


Uterine contractions:

1. Before birth:
   1. brixton-hiks contraction – stronger isolated contractions during pregnancy
   2. dolores praesagientes - “messengers“
2. During birth:
   1. dolores praeparantes – contractions dilating 
   2. the cervix
   3. dolores ad partum – contractions expelling the fetus
   4. dolores ad secundinas – contractions expelling the placenta
3. After birth:
   1. dolores postpartum – contractions wrapping the uterus

Fetus

• Posterior fontanelle
• Anterior fontanelle
• Arrow-shaped seam

  

Fetal lie


4 basic types of fetus lie: 
 

• Longitudinal cephalic (head) presentation - physiological
• Longitudinal breech presentation - physiological
• Oblique - pathological
• Transverse - pathological

the relationship of the fetal back to the uterine margin

4 basic positions:
 

• Left position (first) 
• Anterior – 60%, fetal head rotates 45 degrees
• Posterior – 5 %, fetal head rotates 135 degrees
• Right position (second) 
• Anterior – 5 %, fetal head rotates 45 degrees
• Posterior – 30 %, fetal head rotates 135 degrees

Fetal attitude = relation of the individual parts of the fetus to one another 

the relation of the pressing part of the fetus to the pelvic inlet

Physiological presentation of the fetus:

• Indifferent – lesser and greater fontanelles are at the same height
• centrical – the head is placed symmetrically in the center of the pelvic inlet
• synclitic – the arrow-shaped seam is between the sacral promontory and the pubic symphysis

  

Obstetrical examination

• External
  • Assesses the type of pelvis and the relationship of the fetal head to the plane of the pelvic inlet, measuring pelvic dimensions
• Internal

  

• Internal = vaginal examination
  • It helps to determine the degree of readiness of the birth canal for birth -> dilation of the birth canal
  • Assessment of fetal position
  • Evaluation of the entrance of the fetus in the birth canal
  • Assessment of the fetal press
  • Amniotic fluid – preserved, drains clear / cloudy
  • Bleeding from the birth canal, prolapse of the umbilical cord and small parts of the fetus

The course labor

I. stage
 = opening  

Regular uterine contractions with an opening effect -> disappearance of the birth cervix (10 cm)

Duration:

•  Primipara: 10 – 12 hours
• Multipara: 6 – 8 hours

II. stage = pushing phase

Disappearance of the birth cervix ->  the birth of the fetus

Duration:

•  Primipara: 30 – 40 minutes
• Multipara: 20 – 30 minutes

III. stage = to hospital bed

Child birth -> birth of fetal membranes and placenta

Duration: 10 – 60 minutes

Prevention of postpartum bleeding = active management of the III. stage of labour

Administering uterotonics or utero-kinetics after ligation of the umbilical cord -> reduces postpartum blood loss, contributes to better separation of the placenta and retraction of the uterus after childbirth.


Period of two hours after birth of the fetus = woman in the delivery room, under increased observation

• Control of uterine retraction
• Control of the rate of bleeding from the birth canal
• Measurement of blood pressure, pulse and body temperature

https://youtu.be/dYu-0rOnLpA