In this article month’s blog I’ll discuss one of the various uterine causes of infertility, focusing specifically on a condition in which the uterus is congenitally very small in size—the hypoplastic uterus.
CLINICAL PRESENTATION
Patients usually present during puberty with absent menses. Secondary sexual characteristics are usually present, suggesting that normal ovarian activity may also be present.
TYPES
- Simple hypoplasia: form of the uterus is normal, but is small in size.
- Elongated hypoplasia: fundus is normal, but the length is normal or more than normal.
- Malformative hypoplasia: uterus is arcuate or T- or Y-shaped.
IMAGING
Sonography and MRI are best imaging tools for the diagnosis of hypoplasia of the uterus.
In an ultrasound, hypoplasia of the uterus is usually indicated if the distance between the cornu or intercrual is less than 2 cm or if the distance from the internal os to the fundus is less than 3 to 5 cm.
Sonographic Imaging Features
Vaginal stenosis or aplasia (vagina may be small or absent)
Cervical stenosis (small, narrow cervix)
Small uterus with poorly developed fallopian tubes
(Sometimes a definitive diagnosis may not be possible on ultrasound imaging)
Small uterus with no normal zonal anatomy
In extreme cases, absence of the uterus (aplasia of the uterus)
Constriction bands (focal thickenings of the junctional zone) may be present in the uterus (better seen on MRI)
T-shaped configuration may be seen at times (better seen on MRI)
Endometrial thickness, endometrial cavity area, and endometrial cavity length may be markedly reduced.
Markedly reduced cervical length may be noted
Reduced uterine perfusion may be seen on color Doppler imaging of the uterus.
Mayer Rokitansky Kuster-Hauser syndrome (vaginal agenesis with partial or complete absence of the uterus) is the most common manifestation of uterine hypoplasia/ aplasia
Others have absent vagina with a small rudimentary uterus caused by the failure of the sinovaginal bulb to develop during the embryonic stage.
Small or reduced myometrial volume
Case Presentation 1
Patient was a middle-aged female with h/o primary infertility.
(Images are reproduced from: http://www.ultrasound-images.com/)
Transabdominal sagittal section ultrasound image of uterus
The uterus is small, measuring just 3.8 x 1.2 cm
Transvaginal sagittal section ultrasound image of uterus
The endometrium appears markedly thin.
Transvaginal transverse section ultrasound image of the uterus
Note that the fallopian tubes are visualized (FALL) but appear small and thinned out. The ovaries are poorly visualized in this case.
Case Presentation 2
Here we could only obtain transabdominal ultrasound images of the uterus. Sagittal and transverse ultrasound images, show a markedly hypoplastic uterus, measuring less than 4.8 x 1.6 x 2.7 cm in a middle-aged female patient with primary infertility.
The patient had secondary sexual characteristics in both the above cases, implying the presence of functional ovarian tissue.
