aapko basic science video topic mullerian anomalies mullerian anomalies are the incomplete or abnormal formation and/or fusion of the mullerian or para music network ducts congenital anomalies of the uterus affect two to four percent of women with normal reproductive outcomes for one with adverse reproductive outcomes malaria anomalies occur at greater prevalence from 5 to 25% of women the true incidents can be difficult to determine since many women with uterine anomalies are often asymptomatic and as a result go unrecognized they have a wide range of impact on women and can affect a woman's of centrical outcomes the objectives of this video are described the embryologic origins of the reproductive tract identified genes and hormones involved in sexual differentiation and to understand the pathophysiology of mullerian anomalies let's meet our patient she's a 34 year old gravity' one at 35 weeks gestational age who presents an active labor her pregnancy has been uncomplicated she's 5 centimeters dilated and the fetus is known to be in the frank breech presentation you counseled her that since she is in preterm labor and since the baby is breech you recommend a caesarean section after discussing the risks and benefits she consents to the surgery in the operating room the fuse is mostly on the maternal right when you explore the uterus you feel an indentation in the upper cavity consistent with 2 uterine horns this is most consistent with a bicornuate uterus what causes a bicornuate uterus to understand the pathophysiology is important to remember the embryologic origins of the reproductive system the embryonic disc transported into ectoderm mesoderm and endoderm during the third week between the third and fifth week development of the urogenital tract begins as intermediate musa germ on either side of the fetus the intermediate musa germ gives rise to the urogenital Ridge the urogenital Ridge is further divided into the genital Ridge which ultimately gives rise to the ovary or testes the nephrogenic cord which gives rise to the kidneys and the parameter nephron or malaria ducts in the music metric or wolffian ducts labeled in this image are the gonads the parameter network ducts and the music network ducts the Ducks contact the urogenital sinus which gives rise to the bladder urethra and distal vagina the parameter nefra or malaria ducts give rise to the fallopian tubes uterus and the upper two-thirds of the vagina the music Neff rector wolffian ducts give rise to the uterus which are not demonstrated in this image as well as the male genital ducts including the epididymis and vast difference and seminal vesicles let's look at them side-by-side the mullerian duct structures are shown on the left and the ovary comes from the genital Ridge as an undifferentiated gonna add the wolffian ducts structures are seen on the right as well as the testes which again is from the gentle Ridge from here let's take a closer look at how sexual differentiation occurs on the short arm of the Y chromosome lights the sry gene located in the sex-determining region of the Y chromosome the sry gene encodes for sry protein previously known as testes determining factor or TDF the sry protein leads to good natal differentiation of the testes and produces anti-mullerian hormone and testosterone anti-mullerian hormone causes regression of the parameter network ducts and testosterone drives the persistence and differentiation of the music network ducts let's pause read and apply how does female sexual differentiation occur there is no y chromosome and therefore no sry protein let's take a closer look to see what happens from there if there is no y chromosome there's no production of sry protein and therefore no production of testosterone and anti-mullerian hormone this leads the regression of the music network ducts and persistence of the parameter nefra Cox the parameter network ducts extend downward immediately to fuse in the midline the uterus is formed by this fusion around the 10th week the septum is reabsorbed creating the uterine cavity which is completed at around 20 weeks errors can occur with both fusion and resorption at the distal end the fuse ducts contact the urogenital sinus again the urogenital sinus gives rise to the bladder urethra and distal vagina when the fused pyramids and network ducts contact the urogenital sinus formation of the synovial bulbs is induced the synovial bulbs proliferate and form the vaginal plate canalization occurs to form the vaginal lumen in the second trimester so with our patient what caused the bicornuate uterus there are three main types of bearer the first type of error is an error in fusion with the bicornuate uterus there's a partial fusion of the ducts creating an indent in the fundus with a unicorn uterus there's an asymmetric lateral fusion defect one cavity is usually normal while the other duct is poorly developed uterine didelphis or double uterus is when two mullerian ducts fail diffuse causing duplication of the reproductive structures there can also be errors in septal resorption with a septate uterus there's a normal external surface of the fundus with incomplete resorption of the midline septum between the two mullerian ducts another septal resorption defect is in arcuate uterus there's a slight midline septum with minimal and often broad fundal cavity indentation the last type of error is an error in organogenesis mullerian agenesis also known as MRKH or mire rokitansky kustra Howser syndrome is when all are part of the mullerian tract fails to form or is underdeveloped this typically means an absent vagina with variable uterine development in this laparoscopy image the white arrows are pointing at bilateral uterine remnants let's take a look at a few of these side-by-side bicornuate septate and arcuate uterine anomalies can be difficult to differentiate with bicornuate uterus there is a cleft in the outer contour of the fundus the septate uterus has a normal the outer contour and the septum is usually fibrous between a muscular components in an arcuate uterus there's also a normal outer contour there's a mild indent of the endometrium at the uterine fundus let's take a moment to review errors that can affect the vagina they can be present with uterine anomalies and remember that the parameter network ducts account for the upper two-thirds of the vagina transverse vaginal septa are believed to arise from failed mullerian duct fusion or failed canalization of the vaginal plate they can develop at any level of the vagina another vaginal defect is a longitudinal vaginal septum this results from defective lateral fusion or incomplete reabsorption of the caudal portion of the mullerian ducts these can be partial or extend the complete length of the vagina and can often be seen with uterine didelphis as seen in this drawing let's pause read and apply how-do mullerian anomalies effect breast development is important to remember that the ovaries are derived separately so that women with mullerian anomalies typically have functionally normal ovaries and are phenotypic females with normal breast development alternatively the renal system forms closely with the parameter nephron ducts and as a result renal anomalies are found in 20 to 30 percent of women with mullerian defects once a mullerian anomaly is confirmed women must be evaluated for renal anomalies renal anomalies can be diagnosed with MRI ultrasound or intravenous pyelogram like our patient many women are asymptomatic symptoms can vary greatly depending on the defect some women will present with pelvic pain either cyclic or non cyclic and can develop endometriosis if there's an on communicating functioning horn which can see the peritoneum through retro menstruation women can present with menstrual abnormalities including minimal bleeding or amenorrhea with a Genesis there are also many obstetric complications associated with mullerian anomalies let's review the etiology recurrent pregnancy loss occurs because of impaired uterine distension or implantation and a septum with decreased vascularity entry and growth restriction may occur secondary to abnormal uterine blood flow causing you drove essential insufficiency or a small uterine cavity male presentation is thought to occur secondary to a decreased size of the uterine cavity in addition the decreased uterine size is also postulated to cause an increase in preterm labor retained placenta can occur when the placenta is partially trapped in an upper tapered section of a narrow uterine horn and rarely uterine rupture can occur from pregnancy and obstructed or rudimentary horn how do we diagnose malaria anomalies certainly surgery can diagnose malaria anomalies but imaging modalities such as hysterosalpingogram hysteroscopy ultrasound are helpful and less invasive however these modalities can miss some anomalies including in our patient MRI is still considered the gold standard this MRI image demonstrates a septate uterus this concludes the aapko basic science video on mullerian anomalies we've discussed the unreal adjutant of the reproductive system the role of the sry gene anti-mullerian hormone and testosterone on sexual differentiation and the errors that result in mullerian anomalies [Music] you