Pregnancy diagnosis and management of twin pregnancy in the mare

Question 1

Pregnancy diagnosis in the mare is done (earlier/later) than other species comparatively? Why?

Answer 1

Earlier, because of the presence of the embryonic capsule that maintains the embryo in a round shape for the first 20 days.

Question 2

Pregnancy diagnosis can be done as early as ____ days, but in general it’s more reliable between ___-__ days post ovulation

Answer 2

10

14-16

Question 3

Early pregnancy examination allows us to:

1.
2.
3.

Answer 3

1. Detect the normality of estrous cycle on non-pregnant mares
2. Identify mares with abnormal pregnancies
3. Timely intervention when there are multiple pregnancies or pregnancies are at risk

Question 4

Morphological aspects of the blastocyst:

1.
2.
3.
4.

Answer 4

1. Blastocle
2. Internal cellular mass
3. Capsule (Gly-Prot. Shape)
4. Trophoblast (placenta)

Question 5

Movement of the embryonic vesicle between day ____-____ results in maternal recognition of pregnancy

Answer 5

5.5-16

Question 6

How to distinguish vesicle on U/S?

Answer 6

Hyperechoic embryonic disc on top and bottom of hypoechoic circular vesicle

Question 7

The morphology of the embryonic vesicle allows us to:

1.
2.
3.

Answer 7

1. Diagnose the normalcy of the pregnancy
2. Predict early embryonic death
3. Estimate gestational age

Question 8

What age can you perform diagnostic tests to sex the fetus? What are you looking to identify?

Answer 8

1. 55-65 days

2. Identify the genital tubercule

Question 9

Abnormal vesicle morphology:

1.
2.
3.
4.

Answer 9

1. absence of heartbeat at 30 days
2. Collapsed membranes
3. Diffuse uterine edema during early pregnancy
4. Irregular borders prior to 16 days

Question 10

Twin Pregnancies:

1. __% reach term
2. ___% both are born dead
3. ___% one born alive
4. ___% both are born alive
5. ___% die in the first week

Answer 10

1. 09
2. 64.5
3. 21
4. 14.5
5. 90

Question 11

What kind of repro problems do twins cause in the mare:

1.
2.
3.

Answer 11

1. Dystocia
2. Retained placenta
3. Fertility problems and subsequent heats

Question 12

Why do we miss twin pregnancies?

1.
2.
3.
4.
5.
6.
7.
8.

Answer 12

1. Endometrial cysts
2. Undetected double ovulations
3. Too early pregnancy checks
4. Not scanning the entire uterus
5. Poor quality ultrasounds
6. Inadequate facilities
7. Superimposed vesicles
8. Owners don’t care

Question 13

Twins generally occur due to ____.

Answer 13

Double ovulations

Question 14

Triplets occur naturally in ___% of cases.

Usually due to ____

Answer 14

< 1%

Superovulation

Question 15

Monozygotic twins occur via:

Answer 15

spontaneous division of ICM (inner cell mass)

Question 16

Methods for Twin Reduction: ***

1.
2.
3.
4.
5.
6.
7.
8.

Answer 16

1. Spontaneous reduction
2. Manual reduction (twin crush)
3. Transvaginal aspiration
4. Manual trauma with membrane rupture
5. Craneo-cervical dislocation
6. Intracardial KCL injection

Question 17

When to perform manual crush of twin?

Answer 17

between days 13 to 15. Can separate them manually or with an ultrasound.

Question 18

1. Survival rate after manual reduction of twin if done before the 16th to 20th day?
2. What two things should you give to a mare after twin reduction procedure?

Answer 18

1. > 90%

2. progesterone and flunixin

Question 19

If you notice a twin pregnancy between 20-35 days, what should you do if the twins are:

1. Unilateral?
2. Bilateral?

Answer 19

1. Wait until 30-32 days

2. Reduce one manually

Question 20

Perform transvaginal twin reduction if what age?

Answer 20

35-50 days

Question 21

T/F: Transvaginal twin reduction can be used if unilateral OR bilateral?

Answer 21

T

Question 22

Describe Ultrasound guided transvaginal puncture:

Answer 22

After sedation, uterus is held up against the probe via direct contact with vagina. Guide will indicate where the needle will go through the vagina.

Question 23

Cranio-cervical disolcation:

1. Performed in what age range?
2. Two approaches?

Answer 23

1. 60-100 days

2. Flank or Colpotomy

Question 24

1. When to perform trans-abdominal cardiac puncture?
2. What are you injecting to induce fetal death?
3. Can alternatively inject ___ to reduce twins

Answer 24

1. after 100 days
2. 5 mLs of KCL
3. Potassium Progain Penicllin (PPG)

Question 25

Advantages of injecting PPG over KCL for trans-abdominal cardiac puncture?

1.
2.
3.
4.

Answer 25

1. Reduction in bacterial contamination
2. Visualize PPG
3. Fetal death with pericardial injection
4. Higher success between 115-130 days of gestation (30-60%)