Principles of Obstetrics and Terminology Flashcards
what are some maternal causes of dystocia (4)
-Abnormalities of the pelvis (size, fracture),
-Cervix (ringwomb), Vagina (vaginal
prolapse)
-Uterine torsion
-Uterine inertia
what is ringwomb + what happens
-Failure of cervical dilation
-Genetic link – runs in certain bloodlines
-Normal hormonal changes don’t happen
-No signs of impending labour
-Presents as fetal membranes hanging from vulva
what causes failure of cervical dilation in cows
-In association with uterine torsion
-Or if the calf is dead and does not enter pelvic canal (lack of Fergusson reflex)
what is uterine inertia
Inability to trigger uterine contractions
primary uterine inertia
– Hypocalcemia
– Overstretching – due to hydrops, multiple fetuses
secondary uterine inertia
Exhaustion of the myometrium after prolonged and unsuccessful delivery attempt– inability to continue uterine contractions
fetal causes of dystocia (4)
-Fetal maternal disproportion (Fetus too big or pelvis too small)
-Fetal malalignment (Presentation, posture or position)
-Multiple fetuses (twins, triplets…)
-Fetal monsters
what is the most common cause of dystocia in cattle
Fetal-maternal disproportion
causes of Fetal-maternal disproportion
– Heifers with insufficient pelvic size
– Large fetus too big for normal pelvis
– Large bulls
– Double muscled breeds
– Consider calving ease in bull selection
when can you see Fetal-maternal disproportion in dogs
single pup litter, puppy grows too big for birth canal
what is the most common cause of dystocia in horses and alpacas
Fetal malalignment
what is fetal malalignment
Abnormalities of presentation, posture or position
what is a Congenital abnormalities in cows / what do we see
Schistosomus reflexus
-Spinal curvature
-Thoracic/ abdominal walls
not fused
-ankylosis
what is Perosomus elumbus and what does it look like
-congenital abnormality
-Vertebral agenesis and arthrogryposis
-Front half relatively normal
-Flexure and ankylosis of hindlimbs
-No vertebrae caudal to thorax
-Pelvis is flat
what is an autosomal recessive issue in angus
Neuropathic hydrocephalus
hydrocephalus in horses cause
-Hydrocephalus in Friesian and Belgian horses associated with nonsense mutation in B3GALNT2
-Autosomal recessive
what is Fetal Anasarca and who do we see it in
- Generalized edema
- Esp. bulldogs
what is Fetal ascites
- Abdomen full of fluid
- Assoc. with organ abnormalities
first and second most common causes of dystocia in cows
-Fetopelvic disproportion
-Fetal malalignment
main causes of fetal malalignment in mares
– Head and/or limb deviation; 40-61%
– Posterior presentations; 11 - 50%
– Contracted tendons; 8%
– Transverse; 10-16%
most common cause of dystocia in the bitch and queen
Uterine inertia (complete)
most common causes of dystocia in the ewe
-Fetal malalignment
-Obstruction of birth canal
most common causes of dystocia in the sow
-Uterine inertia
-Fetal malalignment
three features of Describing the Fetal Alignment
- Presentation
- Position
- Posture
what does presentation describe and options
-Describes the relative association of the LONG AXIS of the fetus with the maternal birth canal
-Which half of the fetus is presented first at the entry to the birth canal
Normal is:
– Anterior longitudinal
-or posterior in the cow
how to tell difference between anterior and posterior position
-anterior = These joints bend
in same direction. fetlock and carpus
-posterior = These joints bend
in different direction. fetlock and hock
anterior vs posterior presentation
-Anterior Presentation; palmar aspects of forelimb hooves should be pointing down (unless fetus is upside-down) – feel for head
Posterior Longitudinal;
-Two hindlimbs (hooves) and tail are presented
-Plantar aspects of hooves should bepointing UP
-Careful palpation of joints
-Considered “normal” in cows but usually requires assistance for delivery – PULL!
what does position describe and what is normal
-Describes the surface of the maternal birth canal to which the dorsal part of the fetus is aligned
-Dorsal-sacral is normal (i.e. the dorsum of fetus is aligned with the sacrum of the dam)
what does posture describe and what is normal
-Describes the disposition of the
fetal head, neck and limbs
-Normal is extended head and limbs
(forelimbs if anterior; hindlimbs if posterior)
what position is breech
Breech is Posterior with Bilateral Hip Flexion
what are two abnormal presentations
-transverse
-vertical
transverse presentation; what is it, types
-fetus lies across pelvic inlet
~~dorsal - fetal back at pelvic inlet
~~ventral – all four limbs at pelvic inlet
vertical presentation; what is it, another name
-Vertical – fetus sits vertically in pelvic inlet
-also known as “Dog-Sitting”
appearance of dog sitting during parturition
-Delivery appears normal and then progress suddenly stops
-Fetal hindlimbs are also engaged in pelvis and impede delivery
abnormal positions (2)
-Dorso; pubic (ie upside-down)
-Right or left dorsal- ilial (ie lateral)
abnormal postures (4)
-Describe the abnormally positioned
body part and direction
-Lateral deviation of head and neck
-Ventroflexion of the head
-Carpal flexion; Uni – or bilateral
-Shoulder
what do you need to determine on Initial Exam and Assessment (8)
*History
* General Physical
* Cervix - ? Dilated, Torsion ?
* Fetal viability
* Fetal number
* Uterine tears
* Pelvic size /abnorm.
* Presentation, position and posture
Obstetrical Principles (6)
-Cleanliness
-Lubrication – lots!
-Care and caution
~~Use relaxed haste
~~Avoid excessive force
-Restraint and Location
~~Epidural
~~Sedation
~~General anesthesia (mare)
-Rule of 3 – must have 3 parts presented to pull
-Have a plan and timelines
Lidocaine Epidural; where, outcome
-Very useful
-Sacro-coccygeal or C1-C2 intervertebral space
-Reduces straining to allow easier manipulation of fetus
-May result in more assistance being
required
Toxicity of Polymer Lube
-Linked to acute deaths
-If it goes intraperitoneal results in peritonitis, hemolysis, renal failure and death
-Do not use if C section likely
how can you assess fetal vitality (6)
-Fetal Reflexes
-Disappear from peripheral to central as fetal depression occurs
->Interdigital claw
->Swallowing (Apply pressure to base of tongue)
->Eyeball (disappears last)
->Anal reflex is not
consistent
-Heart beat – umbilical, tail, thorax
-Ultrasound
-ECG
good signs if the calf will fit
- If the fetal fetlocks / hocks can be extended a hands width past the vulva – likely will come
- Hooves out with straining and go in when straining stops
bad signs if the calf will fit
- Prolonged labour and head still not in pelvis
- If you bring up the head and limbs and start pulling and the head goes back, likely not enough room
- Forelimbs crossed
- Volar surfaces of hooves directed medially
- In these cases, immediate C-section is best option if calf alive
Principles in Fetal
Repositioning (3)
-Control of limbs/head
-Repulsion
-Rotation
->Distal limb brought medially
->Joint rotated laterally (Eg. Carpal flexion)
why do you cup the hooves when pulling calves
to prevent trauma to dam
whats the best thing to do to try and get the calf to fit out
Rotate fetus 45 degrees through widest angle of pelvis to prevent hiplock
what is the rule of 3 in obstetrics?
Rule of 3 – must have 3 parts presented to pull
Options for Resolution of
Dystocia (4)
-Assisted Vaginal Delivery AVD (standing)
-Controlled Vaginal Delivery CVD (anesthetized)
-Fetotomy
-Caesarean Section
Assisted Vaginal Delivery; what do you do
-Performed standing (+/- sedation or epidural)
-Reposition fetus
-Deliver fetus in downward arc
-Walk fetus through birth canal one forelimb in front of the other
Traction Guidelines
Need 70 kg force to deliver a calf
-careful when using assisting devices!
Controlled Vaginal Delivery; who is it used in, allows for what
-Under general anesthesia
-Used in mares
-Often permits manipulations and
extraction that are otherwise not possible
-Easy to move quickly onto a fetotomy or C section
