The most commonly under-diagnosed cause of infertility and early miscarriage in Thai patients — how to recognize it, how to confirm it, and how it can be treated.
Adapted and translated from an original article by Dr. Patsama Vichinsartvichai, MD, EFOG, EFRM — Medium, 16 October 2023.
To recognize an abnormal uterus, first picture a normal one. Two flat sheets of uterine muscle (myometrium) sit front and back, with the uterine cavity — lined by the endometrium — sandwiched between them.
In a reproductive-age woman, the normal uterus is roughly 7 cm long overall: the corpus (body) about 4–5 cm and the cervix 2–3 cm, giving a corpus-to-cervix ratio of approximately 2 : 1. Viewed in the mid-coronal plane, the cavity looks like an inverted triangle, with fairly uniform muscle thickness on all three sides.
A dysmorphic uterus — also called a T-shaped uterus — is a congenital malformation in which the lateral walls of the corpus are abnormally thickened. The thick sidewalls squeeze the cavity into a narrow "T" shape instead of the normal inverted triangle.
Cavity forms a wide inverted triangle. Even muscle thickness on all sides.
Thick lateral walls squeeze the cavity into a narrow "T". Same outer shape — very different inside.
This shape isn't just cosmetic. It's associated with:
Many women with a dysmorphic uterus have no idea until they try to conceive. Because it rarely causes classic gynaecological complaints, it's only picked up when someone specifically looks for it. Suspect it if you have any of the following:
Different imaging methods have very different sensitivity for dysmorphic uterus. Some depend heavily on the sonographer's experience. The comparison below summarises what each tool can and cannot tell us:
| Method | External contour | Internal cavity | Suitable for diagnosis? | Notes |
|---|---|---|---|---|
| Diagnostic laparoscopy + hysteroscopy | ✅ | ✅ | ✅ | Expensive; abdominal wound |
| 3D-TVUS (3D transvaginal ultrasound) | ✅ | ✅ | ✅ | Affordable; highly accurate; immediate result |
| HSG (hysterosalpingography) | ❌ | ✅ | ❌ | Low accuracy; radiation; limited cycle-day window |
| 2D-TVUS (2D transvaginal ultrasound) | ⚠️ partial | ✅ | ❌ | Accuracy depends heavily on operator; inexpensive |
The tool used must reliably deliver:
A slim scope (3–4 mm) is passed through the cervix — no external incision. Using the vaginoscopy (no-touch) technique, we skip the speculum and tenaculum, so the exam is much more comfortable. In a normal uterus we see a wide "panoramic" cavity with pink lining and both tubal ostia visible. In a dysmorphic uterus the cavity narrows like a tunnel, the lining looks paler, and the tubal ostia are hidden.
The 3D probe reconstructs the uterus in the mid-coronal plane, showing both the external contour and internal cavity at the same time. Accuracy is high, cost is reasonable, and results are immediate — provided the operator has trained specifically in 3D uterine imaging.
Only shows the uterus from the sagittal view, so a true coronal assessment isn't possible. Diagnosis relies on the sonographer mentally "reconstructing" the shape — which is unreliable, so it is not the right test for confirming dysmorphic uterus.
Same procedure as a tubal-patency test. Shows only the internal cavity; the external contour is invisible, so accuracy is low for this specific diagnosis.
There is not yet an internationally standardized protocol, and randomized controlled trials are still limited. Nevertheless, specialists worldwide agree that women with a dysmorphic uterus who want to conceive should be offered hysteroscopic metroplasty. Every published series has pointed the same way: after surgery, pregnancy rates rise and miscarriage rates fall.
Metroplasty is best done in the early follicular phase — the endometrium is thin, the uterus isn't contracting against the instrument, and visibility is optimal. Under hysteroscopic guidance, the thickened left and right sidewalls are incised in straight lines, and the cuts are gradually extended deeper toward each tubal ostium. The view is oriented from the isthmus upward toward the fundus. No uterine tissue is removed unless another pathology is also present (e.g. an intracavitary polyp or a submucous fibroid).
Below are outcomes for our own patients with dysmorphic uterus who underwent hysteroscopic metroplasty, followed for 12 months (N = 42).
P < 0.001 · 16 of 42 patients delivered a live infant
P < 0.001 · miscarriages fell from 13 to 1
Post-metroplasty outcomes at 12-month follow-up — internal series, LIFE by Dr. Pat (N = 42).
This article is an English adaptation and translation of the original Thai-language essay "Dysmorphic uterus 101: มดลูกวิรูปคืออะไร" by Patsama Vichinsartvichai, MD, EFOG, EFRM — published on Medium on 16 October 2023. Translated and adapted for English-speaking readers with the author's permission.
