Parturition and dystocia

Question 1

What does puerperium mean?

Answer 1

Time taken to return to cyclicity.

Question 2

What does the polypeptide relaxin do?

Answer 2

— Causes relaxation of the pubic symphysis,

vulval and perineal tissues

Question 3

What happens in first stage parturition (onset of uterine contractions)?

Answer 3

Foetus produces cortisol:
Upregulation of enzymes that convert progesterone to oestradiol.
Progesterone declines removing the block on myometrial contractions
Increased basal uterine contractions
Elevated oestrogen increases reproductive tract secretions
(especially from the cervix)

Upregulation of of uterine prostaglandins

Question 4

What are signs of first stage parturition?

Answer 4

Signs include:
. Uterine (not abdominal) contractions
. Anorexia, shivering
‘ Nesting behaviour
. Vulval discharge (due to separation of
placental tissue)

Question 5

What is a sign of second stage parturition?

Answer 5

Abdominal contractions

Question 6

What is the fergusons reflex?

Answer 6

Force fetus against cervix
Neuro-hormonal reflex
Brain release of oxytocin from posterior pituitary
Causing
Myometrial contractions

Question 7

What does primigravida and multigravida mean?

Answer 7

Primi: first pregnancy
Multi: many pregnancies

Question 8

Third stage parturition is about the expulsion of the placenta. Why are myometrial contractions so important in this stage?

Answer 8

Myometrial contractions decrease in amplitude
but become more frequent and less regular
— These are important for dehiscence and expulsion of the foetal membranes
— Not only do the waves of contractions passing from
uterine tube to cervix persist, but in both the cow and
sow there is the reappearance of contractions in the
reverse direction ( a mechanism for dehiscenœ)

Question 9

How long can third stage parturition last in different species?

Answer 9

Third stage lasts from an average of 1 hour in the
mare to 6 hours in the cow.
With the exception of the mare, animals normally eat the placenta.

Question 10

How can foetal position be described?

Answer 10

. Indicates the surface (quadrant) of the maternal birth canal, to which the vertebral column of the foetus is apposed
. It can be:
— Dorsal position
— Ventral position
— Left lateral position
— Right lateral position

Question 11

How can foetal posture be described?

Answer 11

Refers to the disposition of the moveable appendages of the foetus, and involves flexion or extension of the neck and limb joints.

Question 12

How can fetal presentation be described?

Answer 12

Describes the relation between the longitudinal
axis of the foetus and the maternal birth canal
. It can be longitudinal or transverse
. It can be more specific if the part of the foetal
body which is first entering the pelvis is described
e.g.:
— Cranial longitudinal presentation (head first extended forelimbs)
— Caudal longitudinal presentation (hind limbs first)
— Dorsal transverse presentation
— Ventral transverse presentation