Parturition

Question 1

What fetal endocrine axis is required for triggering the onset of parturition?

Answer 1

(The fetal hypothalamic-pituitary-adrenal/HPA axis)

Question 2

What does space limitation stimulate in the fetus that eventually induces parturition?

Answer 2

(ACTH secretion by the fetal pituitary)

Question 3

What triggers the fetal pituitary to start producing ACTH which then triggers parturition?

Answer 3

(Space limitation, triggers parturition through the cortisol released from the adrenals in response to the ACTH)

Question 4

What effect does fetal cortisol have on the progesterone and estrogen levels in the mother?

Answer 4

(Induces the enzymes that form progesterone to instead start making estrogen so progesterone levels fall while estrogen levels rise; also triggers the release of PGF to lyse any luteal structures to further reduce progesterone)

Question 5

Decreasing what hormone removes the block it has on uterine contractions and is a necessary step for the initiation of parturition?

Answer 5

(Progesterone)

Question 6

The rising levels of estrogen close to parturition induce an increase in receptors to what hormone in the reproductive tract?

Answer 6

(Oxytocin receptors)

Question 7

What hormones are important for pelvic ligament relaxation (presents as gluteal muscles sinking, tailhead becoming more prominent, and sacrosciatic ligament softening) and expansion of the birth canal? Two answers.

Answer 7

(Relaxin and estrogen)

Question 8

Fetal cortisol is not only important for triggering parturition, it also is important for final maturations of what structure in the fetus?

Answer 8

(The lungs, specifically cortisol enhances surfactant production which is important for the babies first breath)

Question 9

What hormone is important for synthesis versus ejection of milk from the dam?

Answer 9

(Prolactin is important for synthesis and oxytocin is important for letdown)

Question 10

What is the location of the chorioallantoic membrane in the first stage of parturition?

Answer 10

(It is entering the vagina at this time)

Question 11

What occurs to the chorioallantoic membrane in the second stage of parturition?

Answer 11

(It ruptures after the fetus enters the birth canal)

Question 12

What is the purpose of the uterine contractions in the first stage of parturition (which are mediated by oxytocin, PGF, and estrogen)?

Answer 12

(Aids the fetus in adopting the birthing posture)

Question 13

A failure of what reflex related to parturition can result in dystocia?

Answer 13

(Ferguson reflex → failure of the cervix to dilate may result from malpositioning of the fetus or conditions that prevent stimulation of the ferguson reflex)

Question 14

What is the status of the cervix during the second stage of parturition?

Answer 14

(Cervix will be completely dilated)

Question 15

What other contractions join the uterine contractions in the second stage of parturition?

Answer 15

(Abdominal contractions)

Question 16

Which stage of parturition does placental dehiscence, separation, and expulsion occur within?

Answer 16

(The third stage of parturition)

Question 17

Which of the stages of parturition is the longest?

Answer 17

(The first stage)

Question 18

Change in temperature as a way to predict parturition is most commonly used in what species?

Answer 18

(Dogs, will see a drop to 98-9.5 degrees F)

Question 19

In what time frame will foaling occur if the mare’s milk has transitioned from mildly basic to mildly acidic?

Answer 19

(Foaling will occur within 24 hours)

Question 20

What is the issue with using the appearance of the mammary glands to predict parturition in swine?

Answer 20

(Typically mammary glands become enlarged 1-2 days prior to farrowing in swine but this time frame can be different in sows versus gilts)

Question 21

What disease of the placenta leads to overstretching of the endometrium which can predispose a mom for dystocia?

Answer 21

(Hydrops allantois)

Question 22

If the cervix is closed in a case of uterine torsion, what is the best treatment?

Answer 22

(Perform a c-section as it is rare the cervix will dilate if there is uterine torsion)

Question 23

After what day of gestation can you induce parturition in a cow?

Answer 23

(270 days and beyond)

Question 24

When should a cow calve after the administration of dexamethasone when inducing parturition? Answer is a range.

Answer 24

(24-72 hours later, average is 48 hours)

Question 25

What should be administered with dexamethasone in cattle if you want to shorten the time to calving?

Answer 25

(Prostaglandins, can expect calving within 24-48 hours, average is 36 hours, as opposed to 24-72 with dexamethasone alone)

Question 26

What is a common sequela of induction of parturition in cattle?

Answer 26

(Retained placenta)

Question 27

After what day of gestation can you induce parturition in a ewe?

Answer 27

(137 days and beyond)

Question 28

Why do you only need to use prostaglandins to induce parturition in a doe?

Answer 28

(Does are dependent on their CL for progesterone so once you lyse the CL with PGF, their progesterone falls enough for parturition)

Question 29

After what day of gestation can you induce parturition in a doe?

Answer 29

(144 days and beyond)

Question 30

After what day of gestation can you induce parturition in a sow?

Answer 30

(112 days and beyond)

Question 31

What drug is used for induction of parturition in mares?

Answer 31

(Oxytocin)

Question 32

What are the three Ps in relation to parturition?

Answer 32

(Presentation, position, and posture)

Question 33

What event does stage one of parturition end with?

Answer 33

(The rupture of the chorioallantoic membrane)

Question 34

What event does stage two of parturition end with?

Answer 34

(Passage of the fetus)

Question 35

When should a cow pass the placenta in whole after successful parturition?

Answer 35

(On average, 8 hours)

Question 36

What time of day is preferred by mares for parturition?

Answer 36

(Night, 12-6am specifically)

Question 37

What should occur 1, 2, and 3 hours postpartum for a foal and mare?

Answer 37

(1 hour - foal should be standing; 2 hours - foal should be standing and nursing; 3 hours - placenta should be passed entirely)

Question 38

When should a mare pass the placenta in whole after successful parturition?

Answer 38

(Within 3 hours)

Question 39

When is the placenta considered retained in a small ruminant?

Answer 39

(If it has not passed by 12 hours postpartum)

Question 40

When should a camelid pass the placenta in whole after successful parturition?

Answer 40

(6 hours)

Question 41

Stage II of parturition in camelids can be what duration before you should intervene?

Answer 41

(30-45 minutes)

Question 42

Retained placentas are common or rare in dogs?

Answer 42

(Rare)

Question 43

Retained placentas are common or rare in pigs?

Answer 43

(Rare)

Question 44

What is the position of a fetus if someone tells you they are dorsosacral?

Answer 44

(The fetuses dorsum/spine is towards the dam’s sacrum)

Question 45

What is the position of a fetus if someone tells you they are dorsopubic?

Answer 45

(The fetsuses dorsum/spine is towards the dam’s pubis, tummy is towards the dam’s sacrum)

Question 46

What is the normal presentation of a fetus upon parturition?

Answer 46

(Anterior presentation)

Question 47

What is the normal position of a fetus upon parturition?

Answer 47

(Dorsosacral position)