Delivery in improper fetal position

Breech

  • About 3% of all deliveries
  • Abnormal position requiring the medical aid
  • Average mortality 6-12%

Types

A- complete breech,
B- incomplete breech:
frank breech
footling breech

  • More frequently in:
    preterm deliveries (<32nd week)
    too big or too small fetuses (fetal proportions, big head)
    fetal malformations (hydrocephaly, amelia)
    abnormal uterine shape (unicornual or bicornual uterus, fibroids)
    multifetal pregnancy

course of breech delivery

5 stages

1

  • Engagement of breech into the bony canal 
and passage to the pelvic outlet
  • The intertrochanteric diameter pass the inlet 
with the intertrochanteric diameter 
into the transverse diameter of the bony pelvis
  • After the 2nd rotation one of the buttocks is called 
„anterior” and the other one „posterior”

2

3

  • After passage of the vaginal canal curve, 
buttocks turn to set the intertrochanteric diameter into the a-p diameter of the vaginal canal
  • The lateral flexion of the fetal vertebral column up to the pubic symphysis
  • Buttocks present themselves between vulvar labias
  • Delivery of the trunk:
    With lateral flexion of the vertebral column
    Both limbs fall out free
    Shoulders become engaged in the „inlet” 
– their transverse diameter in the transverse pelvis diameter

4

  • Shoulders delivery:
    Turn to the a-p pelvis diameter
    The „anterior” shoulder presents first
    The „posterior” shoulder afterwards

5

  • Delivery of the head:
    When lower angles of scapulas can be seen, the head becomes engaged in „inlet”
    Its a-p diameter in the transverse pelvic diameter
    Internal rotation
    Head delivery after it touches the pubic symphysis

Diagnosis

external exam – head palpable in uterine fundus 
as rigid and oval structure

Differentiation in external exam

Breech is smaller than head
Rigid and elastic parts of breech
Are not oval
Heart beat auscultated above umbilicus of pregnant woman

Vaginal examination

the presenting part is smaller than head 
without sutures and fontanellae
palpable sacral vertebrae
palpable fisssura between buttocks
no characteristic plane cranial bones

Medical aid

  • Manual assistance - assistance applied after fetal scapulas present themselves between vulvar labias;
  • Manual fetal extraction – manouvers delivering fetus irrespectively to his advancement in the birth canal; usualy assisting doctor hand have to be introduced 
to the vaginal canal or to the uterus.

procedure

Perineum disinfection, Urinary bladder emptying, Local anaesthesia;
Intravenous fluid infusion into which Oxytocine is added during delivery or at least during delivery of shoulders;
Pressure on uterus above pubic symphysis to facilitate 
the engagement of fetal head to the „inlet”
When the fetus is delivered up to the lower brims of scapulas the medical assistance is applied: Bracht manouver, Classical manouver, Lövset manouver, Müller manouver, Veit-Smellie manouver, Wiegand-Martin-Winckel manouver

Classical manouver

  • Right fetal hand is liberated by the right obstetrician’s hand 
and left fetal hand by the left obstetrician’s hand;
  • The „posterior” hand is liberated first;
  • Fetal legs are grasped by the hand corresponding to fetal abdomen and pulled to the opposite side of the liberated hand;
  • The liberated hand is pulled down by sweeping it in front of fetal face
  • Rotation of fetus to make the „anterior” hand the „posterior” one like in Lövset manouver
  • Any traction is forbidden during rotation

Transverse position

  • Delivery cannot be completed without any medical assistance
  • Unassisted delivery lead to the fetal and maternal death
  • The real threat begins after rupture of membranes followed by the intrusion of shoulder to the „inlet” blocking the fetal advacement to the birth canal

assistance

Cesarean section

Internal rotation

  • Can be performed before rupture of membranes 
or when membranes are just ruptured;
  • If membranes are intact - they have to be broken before hand insertion;
  • Obstetrician’s hand inserted into the vagina and uterus;
  • Fetal „anterior” foot (only one) has to be found, grasped and pulled down;
  • Then the fetal manual extraction has to be performed;
  • The assisting person can exert some force above pubic symphysis to facilitate the engagement of fetal head 
to the pelvic inlet.

Improper head position

Vertex - intermediate type

„Deflexion” type

Asynclitic position

High straight station

Low transverse station

stages

Parietal

  • Lead typically to improper „second rotation” 
– forehead to the pubic symphysis
  • In „cheak position” the „proper second rotation” stops 
the delivery progress
  • anterior fontanellum – „leading point”
  • head circumference – 34 cm
  • delivery possible if:
    improper „second rotation”, small fetus, fetus dead, huge pelvic diameters, in multiparas, second twin
  • 3rd rotation
– the rotation point – forehead-hair border
  • huge flexion
  • occipital part delivered first
  • deflexion
  • delivery of face

Frontal

  • leading point – space between nose and greater fontanellum
  • the greatest head circumference – 35-36 cm
  • delayed or absent second rotation
  • delivery possible if:
    improper „second rotation”, small fetus, fetus dead, huge pelvic diameters, in multiparas, second twin
  • 3rd rotation – the rotation point – nose or zygomatic bone
  • huge flexion
  • face & chick delivered first
  • flexion – delivery of face
  • slight deflexion – delivery of cheek

Face

  • leading point – nose and chick
  • the greatest head circumference – 34 cm.
  • deflexion increases during head advancement
  • sequence of delivery:
    cheek, mouth, nose, eyes
  • delivery may become impossible
    if „proper” 2nd rotation – chick to the back – delivery impossible
  • 3rd rotation – the rotation point – space under chick
    flexion, forehead delivered first
  • non axial head engagement 
– usualy due to contracted pelvis
  • anterior asynclitism: favorable
  • posteriori asynclitism: unfavorable
  • no proper engagement of fetal head into inlet
  • delivery not possible, unless:
    small head, huge pelvis
  • no 2nd rotation
  • delivery not possible, unless:
    small head, huge pelvis