Uterine Variants

Question 1

What structure forms the uterus?

Answer 1

Mullerian ducts

Question 2

What should you first look at when scanning the uterus for a variant?

Answer 2

outer surface of the uterus

Question 3

How many main uterine variants are there?

Answer 3

• 6 main variants but anything in between can occur
• many more variants

Question 4

What structures do the uterine variants impact?

Answer 4

cavity or fundus

Question 5

How does the uterus form?

Answer 5

• starts as 2 mullerian ducts that come together & fuse
• fusion pulls upward to create 1 cavity
• wall disappears to create 1 outer cervix & 1 canal

Question 6

How can uterine variants cause fertility issues?

Answer 6

usually can get pregnant, variant can make it difficult to keep the pregnancy

Question 7

Which variant has the best fertility chances?

Answer 7

• variant w/ highest septum b/c it is closest to a “normal” uterus
• can surgically remove septum for better chance at pregnancy, but risk of scar tissue

Question 8

Are uterine variants genetic?

Answer 8

embryological development, not really genetic

Question 9

Can variants cause someone to have more than 1 period?

Answer 9

still just 1 period & 1 hormonal cycle

Question 10

6 main uterine variants

Answer 10

• uterus unicornis (unicornuate)
• uterus subseptus
• uterus septus
• uterus bicornis unicorn
• uterus duplex bicornis
• uterus didelphys (uterus duplex separatus)

Question 11

Uterus unicornis (unicornuate)

Answer 11

• 1 cornua (1 half uterus)
• coronal to body but transverse to uterus
• fudus should be wider towards the top, if it stays round = unicornuate
• endo cavity will be round

Question 12

Uterus subseptus

Answer 12

• not complete separation, below complete
• subtle shortening of endo cavity in sagittal
• single cavity divides only at most superior aspect

Question 13

Uterus septus

Answer 13

• 1 uterus, 2 endo cavities (possibly 2 cervical canals)
• separates entire cavity (most common)
• inferior: single cavity inferiorly
• superior: singular myometrium
• deep division w/single myometrium
• 3D reconstruction much easier to obtain w/single myometrium

Question 14

Uterus bicornis unicorn

Answer 14

• 2 corners, 1 cervix
• 2 half uterine bodies
• cervical anatomy nor demonstrated well due to separated uterine bodies
• look transversely at cervix to confirm

Question 15

Uterus duplex bicornis

Answer 15

• 2 corners, 2 cervix
• 2 half uterine bodies
• cervical anatomy not demonstrated well due to separated uterine bodies
• look transversely at cervix to confirm

Question 16

Uterus didelphys (uterus duplex separatus)

Answer 16

• completely separate, 2 half uteri
• note disconnect of the cavity
• 2 cervices shown in inferior, 2 uterine bodies shown in superior
• can only differentiate from duplex bicornis if 2 sides are really far away
• best confirmed in surgery
• difficult to do 3D reconstruction

Question 17

What type of variant would the uterus be if there are 2 cavities?

Answer 17

• 2 cavities doesn’t mean it’s bicornuate
• pay attention to myometrium

Question 18

What is 3D surface rendering used for?

Answer 18

• variable depth fields
• can’t see baby’s face if no fluid around it, or if face is pressed against wall/placenta

Question 19

What is multiplanar reconstuction used for?

Answer 19

looking at cavity of uterus

Question 20

Arcuate uterine variant

Answer 20

• small indentation of fundal endometrium
• heart-shaped uterus
• fundal cleft <1cm w/in single myometrium
• babies can be born early

Question 21

Uterine variant imaging

Answer 21

• multiple images/planes required
• distinction btwn. bicorn/sept is imperative
• 3D/multiplanar reconstruction required