Lecture 8: Diagnosis of Pregnancy (Macpherson)

Question 1

Methods for pregnancy dx

Answer 1

• behavioral assessment
• vaginal speculum exam
• transrectal palpation*
• transrectal ultrasound*
• hormonal assays

Question 2

insensitive indicator of pregnancy**

Answer 2

progesterone (can be pregnancy or diestrus!)

Question 3

vaginal speculum exam

Answer 3

• looks at cervix
• indicator of progesterone
• insensitive indicator of preg.

Question 4

what does cervix under influence of progesterone look like?

Answer 4

closed, white, tight

Question 5

uses/advantages of transrectal palpation

Answer 5

• useful at all stages
• rapid
• economical
• often paired with ultrasound

Question 6

uses/advantages of ultrasound

Answer 6

• earlier detection of preg.
• detect twins, EED
• age estimation
• fetal sexing

Question 7

pregnancy dx usually done at what gestation?

Answer 7

13-18d

Question 8

what should you expect to see/feel at 13-18d gestation?

Answer 8

• good tubular tract tone
• distinct uterine bifurcation
• active ovaries
• tightly closed cervix
• false positives can occur (i.e. uterine cysts diagnosed as vesicles)
• can NOT palpate vesicle yet

Question 9

Are mare ovaries active throughout pregn?

Answer 9

Y

Question 10

Dx of twins

Answer 10

-ultrasound at 13-15d. If you ultrasound sooner, you may miss a twin pregnancy

Question 11

synchronous vs. asynchronous ovulation

Answer 11

asynchronous: ovulate first follicle, then ovulate second a few days later
- one follicle will be larger than the other
synchronous: ovulate both follicles at the same time

Question 12

best time to do manual embryo crush. success rate?

Answer 12

16-17d (90%)

Question 13

what should you expect to see/feel at 20-25d gestation?

Answer 13

• toned uterus
• narrow, elongated cervix
• rarely detectable with palpation
• guitar pick shape
• embryonic heartbeat (DAY 24)
• ovarian activity
• capsule lost as vesicle fixes at base of one of the uterine horns

Question 14

what surrounds embryo at around day 22-40?

Answer 14

yolk and allantoic sacs

Question 15

what should you expect to see/feel at 30-35d gestation?

Answer 15

• toned uterus
• narrow, elongated cervix
• Hen’s egg bulge at base of uterine horn

Question 16

yolk vs. allantoic sac

Answer 16

embryo eats yolk sac and excretes waste into allantoic sac

Question 17

when can you first hear embryonic heartbeat?

Answer 17

day 24

Question 18

what should you expect to see/feel at 35-40d gestation?

Answer 18

• good uterine tone
• narrow, elongated cervix
• tennis ball-shaped bulge

Question 19

majority of EED occurs by day ___

Answer 19

35

Question 20

when is good time to check for EED?

Answer 20

day 38.

Question 21

What will you see in EED?

Answer 21

membranes separate away, loss of heartbeat.

-ALWAYS re-check to make sure!

Question 22

what should you expect to see/feel at 45-50d gestation?

Answer 22

• good uterine tone
• narrow, elongated cervix
• softball shaped vesicle
• fetus suspended by umbilicus

Question 23

when does embryo become fetus?

Answer 23

~40 days

Question 24

endometrial cups

Answer 24

trophoblastic structures that form from cells of the chorionic girdle of embryo migrating over to the uterus

• secrete equine chorionic gonadotropin (eCG), which causes 2ary CL to secrete additional progesterone to maintain pregnancy
• form around day 36

Question 25

why do you want to detect twins before form. of endometrial cups?

Answer 25

they persist after fetal death and will prevent mare from coming back into heat quickly; makes it hard to re-breed

Question 26

management of fetal twins and success rates

Answer 26

- transvaginal ultrasound-guided aspiration (30%) - cranio-cervical dislocation (60%) - transabdominl ultrasound-guided cardiac puncture (60-65%)

Question 27

what should you expect to see/feel at 60d gestation?

Answer 27

- vesicle expands into uterine body - small football shape - less tone in gravid horn - non-gravid horn toned

Question 28

genital tubercle differentiates into:

Answer 28

- external genitalia of female under tailhead (vulv and clitoris) - prepuce of male

Question 29

what should you expect to see/feel at 75-120d gestation?

Answer 29

- uterus pulled ventrally - size of basketball - differentiate from bladder (palpate to cervix) - ovaries closer to midline - difficult to image transrectally

Question 30

gender ID at how many days?

Answer 30

100

Question 31

HR should be what until last 30 days of gestation?

Answer 31

75 BPM

Question 32

what should you expect to see/feel at 150-200d gestation?

Answer 32

- uterine descent complete - fetal ballottment consistent - transabdominal ultrasound approach best

Question 33

why can't use membrane slip in mares

Answer 33

due to diffuse epitheliochorial type placenta

Question 34

sensitive indicators of pregnancy

Answer 34

- transrectal ultrasound** | - transrect. palpation

Question 35

insensitive indicators of preg.

Answer 35

- behavior - cervical changes - hormonal assays

Question 36

when is progesterone false indicator of preg?

Answer 36

diestrus

Question 37

when is eCG false + of preg?

Answer 37

dead fetus (up to 200 days of gestation)

Question 38

when can estrogens be measured in gestation? What is there use?

Answer 38

between 80-100 and mid-200s days of gest. - measure of fetal viability - prod. by fetal placental unit

Question 39

T/F: progesterone, eCG, and estrogens are all minimally useful for preg. dx**

Answer 39

T!

Question 40

fetal orbit measurement

Answer 40

used to approx. gestation (i.e. 5.8=300 days) - only used in late gestation - transrectal

Question 41

CTUP

Answer 41

combined thickness of uterus and placenta | -elevation indicates abnormality such as inflamm, infection, etc.