Re: BU and SU - the difference between them

[Guest guest]

> Can anybody tell me the difference between a BU and a SU?

Hi,

Well, let's see if I can remember this.

BU: is a uterus which failed to " fuse " during embryonic development.

This means there are 2 seperate uterine cavities, also called horns,

divided by a uterine wall. This dividing wall can support a

pregnancy, because it is the same type of endometrial tissue as the

outer walls of the uterus. From the outside view, a BU has an

obvious dip in the fundus (top of the uterus). It is commonly

referred to as a heart shaped uterus - picture the dip in the top of

the heart. How deep the dip is depends on the severity of the

division.

SU: in the normal embrological develpment of the uterus, there is a

septum in the middle of the uterus that is supposed to dissolve.

With SU, this doesn't happen. So, this dividing tissue is unlike BU

(in BU, as I said, the dividing tissue is endometrium and can support

pregnancy). In SU, the tissue is avascualr - with little or no blood

flow - and so if a pregnancy implants here it will most likely not

thrive. This will depend, of course, on the severity of the septum

(sometimes the failure of the septum to dissolve was only partial, so

the septum is small). Also, in some cases a pregnany can implant

away from the septum and be fine.

In SU, from the outside view, the fundus has a very slight indent or

none at all (although some MA's can be a BU/SU combo with both a

deeper fundal indent and a septum).

This is why when diagnosing between BU and SU it is important NOT to

rely upon HSG alone, which only examines the inner contour of the

uterus. If only the inside is looked at, and the outer fundal

contour is ignored, many women who actually do have SU are

misdiagnosed as BU. From the inside, viewed by HSG, BU and SU look

the same. The lap/hyst is the gold-standard because it presents the

entire picture - inner and outer uterus.

Below is an excerpt from an article found on the links page - I

basically said the same thing above.

Hope that helps.

SU rsected, bicollis (2 cervices), vag. septum, one kidney

This comes from the following article:

http://www.hygeia.org/poems24.uterine%20anomalies.htm

IV) Bicornuate

This is the most common congenital uterine anomaly (45% - Patton et

al., '94). It results from a failure of fusion between the mullerian

ducts at the 'top'. This failure may be " complete " which results in a

two separate single horn uterine bodies sharing one cervix.

Alternatively, in a " partial " bicornuate uterus fusion between the

mullerian ducts occurred at the 'bottom', but not the 'top'. Thus,

there is a single uterine cavity at the bottom with a single cervix,

but it branches into two distinct horns at the top. Since the ducts

never fused at the top, these two horns are separate structures when

seen from the outside of the uterus.

(V)Septate

A septate uterus results from a problem in stage 2 or 3 of uterine

development. The two mullerian ducts fused normally; however, there

was a failure in degeneration of the median septum. If this failure

was " complete " , a median septum persists in the entire uterus

separating the uterine cavity into two single-horned uteri which

share one cervix. If this failure was " partial " , resorption of the

lower part of the median septum occured in stage 2, but the top of

the septurn failed to dissolve in stage 3. Hence, there is a single

cervix and uterine cavity at the bottom, but at the top that cavity

divides into 2 distinct horns. Since this uterine anomaly occurs

later in uterine development after complete duct fusion, the external

shape of the uterus is a single unit (normal appearing). This is

distinct from the bicornuate uterus which can be seen branching into

two distinct horns when viewed from the outside.

[Guest guest]

> Can anybody tell me the difference between a BU and a SU?

Hi,

Well, let's see if I can remember this.

BU: is a uterus which failed to " fuse " during embryonic development.

This means there are 2 seperate uterine cavities, also called horns,

divided by a uterine wall. This dividing wall can support a

pregnancy, because it is the same type of endometrial tissue as the

outer walls of the uterus. From the outside view, a BU has an

obvious dip in the fundus (top of the uterus). It is commonly

referred to as a heart shaped uterus - picture the dip in the top of

the heart. How deep the dip is depends on the severity of the

division.

SU: in the normal embrological develpment of the uterus, there is a

septum in the middle of the uterus that is supposed to dissolve.

With SU, this doesn't happen. So, this dividing tissue is unlike BU

(in BU, as I said, the dividing tissue is endometrium and can support

pregnancy). In SU, the tissue is avascualr - with little or no blood

flow - and so if a pregnancy implants here it will most likely not

thrive. This will depend, of course, on the severity of the septum

(sometimes the failure of the septum to dissolve was only partial, so

the septum is small). Also, in some cases a pregnany can implant

away from the septum and be fine.

In SU, from the outside view, the fundus has a very slight indent or

none at all (although some MA's can be a BU/SU combo with both a

deeper fundal indent and a septum).

This is why when diagnosing between BU and SU it is important NOT to

rely upon HSG alone, which only examines the inner contour of the

uterus. If only the inside is looked at, and the outer fundal

contour is ignored, many women who actually do have SU are

misdiagnosed as BU. From the inside, viewed by HSG, BU and SU look

the same. The lap/hyst is the gold-standard because it presents the

entire picture - inner and outer uterus.

Below is an excerpt from an article found on the links page - I

basically said the same thing above.

Hope that helps.

SU rsected, bicollis (2 cervices), vag. septum, one kidney

This comes from the following article:

http://www.hygeia.org/poems24.uterine%20anomalies.htm

IV) Bicornuate

This is the most common congenital uterine anomaly (45% - Patton et

al., '94). It results from a failure of fusion between the mullerian

ducts at the 'top'. This failure may be " complete " which results in a

two separate single horn uterine bodies sharing one cervix.

Alternatively, in a " partial " bicornuate uterus fusion between the

mullerian ducts occurred at the 'bottom', but not the 'top'. Thus,

there is a single uterine cavity at the bottom with a single cervix,

but it branches into two distinct horns at the top. Since the ducts

never fused at the top, these two horns are separate structures when

seen from the outside of the uterus.

(V)Septate

A septate uterus results from a problem in stage 2 or 3 of uterine

development. The two mullerian ducts fused normally; however, there

was a failure in degeneration of the median septum. If this failure

was " complete " , a median septum persists in the entire uterus

separating the uterine cavity into two single-horned uteri which

share one cervix. If this failure was " partial " , resorption of the

lower part of the median septum occured in stage 2, but the top of

the septurn failed to dissolve in stage 3. Hence, there is a single

cervix and uterine cavity at the bottom, but at the top that cavity

divides into 2 distinct horns. Since this uterine anomaly occurs

later in uterine development after complete duct fusion, the external

shape of the uterus is a single unit (normal appearing). This is

distinct from the bicornuate uterus which can be seen branching into

two distinct horns when viewed from the outside.

[Guest guest]

> Can anybody tell me the difference between a BU and a SU?

Hi,

Well, let's see if I can remember this.

BU: is a uterus which failed to " fuse " during embryonic development.

This means there are 2 seperate uterine cavities, also called horns,

divided by a uterine wall. This dividing wall can support a

pregnancy, because it is the same type of endometrial tissue as the

outer walls of the uterus. From the outside view, a BU has an

obvious dip in the fundus (top of the uterus). It is commonly

referred to as a heart shaped uterus - picture the dip in the top of

the heart. How deep the dip is depends on the severity of the

division.

SU: in the normal embrological develpment of the uterus, there is a

septum in the middle of the uterus that is supposed to dissolve.

With SU, this doesn't happen. So, this dividing tissue is unlike BU

(in BU, as I said, the dividing tissue is endometrium and can support

pregnancy). In SU, the tissue is avascualr - with little or no blood

flow - and so if a pregnancy implants here it will most likely not

thrive. This will depend, of course, on the severity of the septum

(sometimes the failure of the septum to dissolve was only partial, so

the septum is small). Also, in some cases a pregnany can implant

away from the septum and be fine.

In SU, from the outside view, the fundus has a very slight indent or

none at all (although some MA's can be a BU/SU combo with both a

deeper fundal indent and a septum).

This is why when diagnosing between BU and SU it is important NOT to

rely upon HSG alone, which only examines the inner contour of the

uterus. If only the inside is looked at, and the outer fundal

contour is ignored, many women who actually do have SU are

misdiagnosed as BU. From the inside, viewed by HSG, BU and SU look

the same. The lap/hyst is the gold-standard because it presents the

entire picture - inner and outer uterus.

Below is an excerpt from an article found on the links page - I

basically said the same thing above.

Hope that helps.

SU rsected, bicollis (2 cervices), vag. septum, one kidney

This comes from the following article:

http://www.hygeia.org/poems24.uterine%20anomalies.htm

IV) Bicornuate

This is the most common congenital uterine anomaly (45% - Patton et

al., '94). It results from a failure of fusion between the mullerian

ducts at the 'top'. This failure may be " complete " which results in a

two separate single horn uterine bodies sharing one cervix.

Alternatively, in a " partial " bicornuate uterus fusion between the

mullerian ducts occurred at the 'bottom', but not the 'top'. Thus,

there is a single uterine cavity at the bottom with a single cervix,

but it branches into two distinct horns at the top. Since the ducts

never fused at the top, these two horns are separate structures when

seen from the outside of the uterus.

(V)Septate

A septate uterus results from a problem in stage 2 or 3 of uterine

development. The two mullerian ducts fused normally; however, there

was a failure in degeneration of the median septum. If this failure

was " complete " , a median septum persists in the entire uterus

separating the uterine cavity into two single-horned uteri which

share one cervix. If this failure was " partial " , resorption of the

lower part of the median septum occured in stage 2, but the top of

the septurn failed to dissolve in stage 3. Hence, there is a single

cervix and uterine cavity at the bottom, but at the top that cavity

divides into 2 distinct horns. Since this uterine anomaly occurs

later in uterine development after complete duct fusion, the external

shape of the uterus is a single unit (normal appearing). This is

distinct from the bicornuate uterus which can be seen branching into

two distinct horns when viewed from the outside.