Lecture 8: Diagnosis of Pregnancy (Macpherson) Flashcards
Methods for pregnancy dx
- behavioral assessment
- vaginal speculum exam
- transrectal palpation*
- transrectal ultrasound*
- hormonal assays
insensitive indicator of pregnancy**
progesterone (can be pregnancy or diestrus!)
vaginal speculum exam
- looks at cervix
- indicator of progesterone
- insensitive indicator of preg.
what does cervix under influence of progesterone look like?
closed, white, tight
uses/advantages of transrectal palpation
- useful at all stages
- rapid
- economical
- often paired with ultrasound
uses/advantages of ultrasound
- earlier detection of preg.
- detect twins, EED
- age estimation
- fetal sexing
pregnancy dx usually done at what gestation?
13-18d
what should you expect to see/feel at 13-18d gestation?
- 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
Are mare ovaries active throughout pregn?
Y
Dx of twins
-ultrasound at 13-15d. If you ultrasound sooner, you may miss a twin pregnancy
synchronous vs. asynchronous ovulation
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
best time to do manual embryo crush. success rate?
16-17d (90%)
what should you expect to see/feel at 20-25d gestation?
- 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
what surrounds embryo at around day 22-40?
yolk and allantoic sacs
what should you expect to see/feel at 30-35d gestation?
- toned uterus
- narrow, elongated cervix
- Hen’s egg bulge at base of uterine horn
yolk vs. allantoic sac
embryo eats yolk sac and excretes waste into allantoic sac
when can you first hear embryonic heartbeat?
day 24
what should you expect to see/feel at 35-40d gestation?
- good uterine tone
- narrow, elongated cervix
- tennis ball-shaped bulge
majority of EED occurs by day ___
35
when is good time to check for EED?
day 38.
What will you see in EED?
membranes separate away, loss of heartbeat.
-ALWAYS re-check to make sure!
what should you expect to see/feel at 45-50d gestation?
- good uterine tone
- narrow, elongated cervix
- softball shaped vesicle
- fetus suspended by umbilicus
when does embryo become fetus?
~40 days
endometrial cups
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
why do you want to detect twins before form. of endometrial cups?
they persist after fetal death and will prevent mare from coming back into heat quickly; makes it hard to re-breed
management of fetal twins and success rates
- transvaginal ultrasound-guided aspiration (30%)
- cranio-cervical dislocation (60%)
- transabdominl ultrasound-guided cardiac puncture (60-65%)
what should you expect to see/feel at 60d gestation?
- vesicle expands into uterine body
- small football shape
- less tone in gravid horn
- non-gravid horn toned
genital tubercle differentiates into:
- external genitalia of female under tailhead (vulv and clitoris)
- prepuce of male
what should you expect to see/feel at 75-120d gestation?
- uterus pulled ventrally
- size of basketball
- differentiate from bladder (palpate to cervix)
- ovaries closer to midline
- difficult to image transrectally
gender ID at how many days?
100
HR should be what until last 30 days of gestation?
75 BPM
what should you expect to see/feel at 150-200d gestation?
- uterine descent complete
- fetal ballottment consistent
- transabdominal ultrasound approach best
why can’t use membrane slip in mares
due to diffuse epitheliochorial type placenta
sensitive indicators of pregnancy
- transrectal ultrasound**
- transrect. palpation
insensitive indicators of preg.
- behavior
- cervical changes
- hormonal assays
when is progesterone false indicator of preg?
diestrus
when is eCG false + of preg?
dead fetus (up to 200 days of gestation)
when can estrogens be measured in gestation? What is there use?
between 80-100 and mid-200s days of gest.
- measure of fetal viability
- prod. by fetal placental unit
T/F: progesterone, eCG, and estrogens are all minimally useful for preg. dx**
T!
fetal orbit measurement
used to approx. gestation (i.e. 5.8=300 days)
- only used in late gestation
- transrectal
CTUP
combined thickness of uterus and placenta
-elevation indicates abnormality such as inflamm, infection, etc.
