Dysmorphic uterus: the most omitted cause of infertility
Patsama Vichinsartvichai
MD., MClinEmbryol, EFOG-EBCOG, EFRM-ESHRE/EBCOG.
Dysmorphic uterus aka. T-shaped uterus is a congenital malformation of the uterus that involve the abnormally thick side wall muscle of uterus that constricted the uterine cavity into the shape of letter T (instead of triagle). It is a common cause of infertility. I conducted a research collecting data in all infertility patients who began to be treated with 3D ultrasound (3D-TVUS) and found that up to 27% of infertile women had dysmorphic uterus. Moreover, the congenital malformatoin of the uterus is the most common cause of infertility that overlooked by infertility physician. Eventhough the surgical correction nowaday is simple and straight forward and the result of the treatment is very promising.
What is Normal Uterus?
The normal uterus can be defined by three characteristics. Firstly, the uterus consists of two sheets of flat pear-shaped muscle (aka. myometrium) overlying each other in front-back arrangement. The potential space inside these two sheets of muscle is called the uterine cavity which lined by endometrium which regenerate every menstrual period to acccommodate the implantation of the embryo as shown in Figure 1A.
Secondly, the length of the uterus is about 7 cm in reproductive age women where 4-5 cm top part belongs to body of the uterus while the 2-3 cm botton belongs to the cervix. This determine the proportion of normal uterus in body:cervix to 2:1 (Figure 1B).
Figure 1 A. Show the layer of tissue in the uterus, which consists of 2 rough elements, namely the uterine lining (endometrium) and uterine muscles (myometrium) B. Show various parts of the uterus that develop from the Müllerian tube, including the cervix (cervix), uterus (corpus uteri) and fallopian tubes (fallopian tubes).
Thirdly, the shape of the uterine cavity when we look at the front-back axis (midcoronal view) is an inverted triangle shape (Figure 2A.). And the uterine muscles flank the uterine cavity on three sides (left, right, and top) should be homogeneous in the thickness.
What is Dysmorphic Uterus?
Dysmorphic uterus or T-shaped uterus is characterized by the thickening of the side wall muscle of the uterus that deform the uterine cavity from triangle to shape of letter 'T' (Figure 2B).
Figure 2 A. The normal uterus characterized by homogenously thick side and top wall and triangle shape cavity B. The dysmorphic uteurs characterized by thick side wall and narrowing cavity in the shape of letter 'T'.
Dysmorphic uterus associates with decrease blood supply to the endometrium and limited the expansion capacity of uterus to accommodate the growing fetus after implantation.
What are the symptoms of dysmorphic uterus? Are you at risk?
A woman with dysmorphic uterus does not have specific symptom unless you want to have a baby. The problem is about embryo implantation and fetal growth in utero so these following might be only the clue that you might have dysmorphic uterus as shown in Figure 3.
Figure 3 shows symptoms or common symptoms in patients with dysmorphic T-shaped uterus.
- You have LIGHT but REGULAR period
From my tirelessly interview with patient and record some statistics, this is the figure that urge you to have a serious check. If you use THREE or LESS sanitary pads on your heavy flow day, it might indicate that you have dysmorphic uterus.
- Miscarriage especially in the first trimester more than once
Only if you just have a positive pregnancyt test (from blood) and it's gone just a little after that, you see the sac but later it's still empty or you see the fetal heartbeat but it stops later on, these are all count as miscarriage. The time when you miscarriage in woman with dysmorphic uterus is usually at the similar gestational age.
Reproductive age woman bleed every month when you have period so the red blood cell concentration (hematocrit) is usually around 34-38%. If your results is over 40%, you might have light period which listed no. 1 here.
4. You did IVF and transfer good quality blastocyst (especially with normal chromosome result) but you still fail.
You invested a sh*t load of money to do an IVF cycle, biopsy and do chromosome test. There are many utilizable embryos but none of them implant when you put it back. If this happens to you, there's a significant risk that you might have dysmorphic uterus. Bringing home a baby requires TWO parts that are equally essential; good embryo and good uterus. You already fix the first, the true problem might come from the latter.
Diagnosis of T-shaped uterus
The good diagnostic tool for congenital malformatoin of the uterus must provide the accurate information of these features.
Generate the image of the uterus in the front to back view (midcoronal view)
External contour of the uterus.
Shape of internal uterine cavity
These following are the diagnostic techniques of choice for the detection of dysmorphic uterus:
Diagnostic hysteroscopy
The use of the endoscope that diameter < 3.5 mm is the gold standard to diret visualization of the vagina, cervix and uterine cavity without causing surgical wounds. Additionally, the vaginoscopy technique where the hysteroscope was applied into vagina, cervix and uterine cavity without the insertion of vaginal speculum or tenaculum. Both size and insertion technique contribute to the era of office hysteroscopy due to less pain and more comfort of patients The characteristics of the uterus detected through the endoscope as shown in the Figure 4
Figure 4 shows the wide-angle uterus (panoramic view) of the uterine cavity through the hysteroscope. A. Normal uterus (normal uterus) sees a wide uterine cavity. Pink uterine lining and the opening of tubal ostia were demostrated (⬆︎ arrow shows the fallopian tube opening) B. Dysmorphic uterus represents the narrow uterine cavity ascending into a tunnel. Pale uterine lining And do not see the fallopian tube opening.
3D Vaginal Ultrasound (3D-TVUS)
3D-TVUS can easily generate mid-coronal image of the uterus, demarcating external contour and internal cavity. The ultrasound is inexpensive, zero turnaround time.However, the optimization of 3D-TVUS image require additional practice. The characteristics of the uterus from the three-dimensional ultrasound examination of the vagina as shown in the Figure 5.
Figure 5 shows the characteristics of the uterus from the three-dimensional ultrasound examination of the vagina (3D-TVUS) A. Normal uterussaw 1 uterus, one uterus cavity. The uterus is a triangle. B. Dysmorphic uterus (dysmorphic uterus) sees 1 uterus, a single cavity. The side of the uterus has a thick uterine muscle, making the uterus shape like the letter T.
Two-Dimensional Ultrasound (2D-TVUS)
Can see the side uterus image (saggital veiw) only, making it not very suitable for diagnosis. Because the examiner must have high ultrasound skills And must rely on the imagination of the examiner, unable to measure the angle in the coronal view, causing poor accuracy
Hysterosalpingography (HSG)
Is the same examination as the fallopian tube examination Can see the internal cavity, but cannot tell the external contour, making low accuracy
Treatment
Hysteroscopic Metroplasty
Currently, there is no universally accepted treatment. And still lack of study of the results of research treatment with a comparative group (RCT). However, experts around the world agree that women with dysmorphic uterus who wants to have children should have surgery to adjust the uterus to normal aka. 'hysteroscopic metroplasty' . After surgery, the patient will have a much better pregnancy outcomes. Reduce miscarriage and preterm birth.
Figure 6 shows the treatment of dysmorphic T-shaped uterus with hysteroscopic metroplasty.
Hysteroscopic metroplasty can be operated during the early follicular phase because the uterine lining (endometrium) is not thick. And the uterus contraction naturally work with us in synchromy. There is a principle shown in Figure 6, that is, it is a cut of the left-right uterine muscle in a straight line. And gradually cut the uterine muscle in such lines to go deeper until seeing the opening point of the fallopian tube (tubal ostium) from looking up from the isthmus of the uterus without cutting any parts of the uterus, except for other pathologies found in the uterine cavity, such as polyps in the uterus. Or submucous uterine tumors
Postoperative care
After surgery, patients can often return to daily life almost normal. Because the surgery is inserting the cervical camera into the uterus No wound on the abdomen May have a little vaginal bleeding, especially within the first 1 week
It is recommended to refrain from sex 1 month after surgery or until the next menstrual cycle comes. Because it may cause endometritis to infect
Fibrosis in the uterine cavity after surgery can be prevented by the orientation of the wound to the left-right area, which is very likely to cause scars. Inserting a protective gel to prevent fibrosis in the uterine cavity immediately after surgery. Eating high estrogen to stimulate the endometrium to cover the surgical area Preventing infection after surgery wit B or vaginal three-dimensional ultrasound (3D-TVUS) to assess the shape of the uterus after surgery whether it has returned to normal or not.
Examination with diagnostic hysteroscopy with vaginoscopy technique can be done at the outpatient. It does not take long. The patient feels a little pain or no pain at all (Picture 7)
Figure 7 shows the uterine cavity from diagnostic hysteroscopy in patients with the same dysmorphic uterus. A.Uterine cavity before surgery, observe the pale color of the uterine lining, the uterine cavity is narrow, deep and the fallopian tube opening is not seen. B. The uterine cavity after hysteroscopic metroplasty 5 weeks shows the normal wide uterine cavity. The uterine lining has normal blood and sees the opening of the fallopian tubes on both sides.
Postoperative planning can be allowed to have children naturally or start stimulating eggs to make IVF after the postoperative examination.
In the case of planning to move frozen embryos, it is recommended to rest at least 2 menstrual cycles, then start preparing the uterine wall to move the frozen embryo.
Patient's instruction before and after hysteroscopy
Results of the surgery
The reproduction of dysmorphic uterus woman after hysteroscopic metroplasty is shown in Figure 8. The surgery significantly improves the pregnancy rate and alleviates the abortion rate. Almost 70% of the pregnancy is spontaneous and mean time-to-pregnancy is around 5-6 months.
Figure 8 The reproduction of dysmorphic uterus patients after hysteroscopoic metropalsty. A. The cumulative pregnancy rate 1 year after surgery B. How they get pregnant and C. Average time to pregnancy
Summary
Dysmorphic T-shaped uterus (dysmorphic T-shaped uterus) is a congenital abnormality of the uterus that is common in infertility and is the cause of infertility and miscarriage.
Patients often have little menstruation. (A lot of days, use no more than 3 tampons, less than 4 days), frequent abortions, making IVF and moving embryos that are normally not pregnant.
Diagnosis using three-dimensional ultrasound (3D-TVUS) or hysteroscopy.
Treatment with hysteroscopic metroplasty
Surgery clearly increases the chance of pregnancy and reduces the chance of miscarriage.
Reference
Patsama Vichinsartvichai. Chapter 11 Dysmorphic uterus. In Patsama Wijinsart Research. Congenital malformation of the uterus Congenital malformation of uterus. 1st edition of May Prof. 2565
Coelho Neto MA, Ludwin A, Petraglia F, Martins WP. Definition, prevalence, clinical relevance and treatment of t-shaped uterus: Systematic review. https://doi.org/10.1002/uog.23108. Ultrasound in Obstetrics & Gynecology. 2021/03/01 2021;57(3):366-377.