The arcuate uterus is a form of a uterine anomaly or variation where the

uterine cavity The uterine cavity is the inside of the uterus. It is triangular in shape, the base (broadest part) being formed by the internal surface of the body of the uterus between the openings of the fallopian tubes, the apex by the internal orifice of the ...

displays a concave contour towards the fundus. Normally the uterine cavity is straight or convex towards the fundus on anterior-posterior imaging, but in the arcuate uterus the myometrium of the fundus dips into the cavity and may form a small septation. The distinction between an arcuate uterus and a

septate uterus A uterine septum is a form of a congenital malformation where the uterine cavity is partitioned by a longitudinal septum; the outside of the uterus has a normal typical shape. The wedge-like partition may involve only the superior part of the cavi ...

is not standardized.

Signs and symptoms

The condition may not be known to the affected individual and not result in any reproductive problems; thus normal pregnancies occur. Indeed, there is no consensus on the relationship of the arcuate uterus and

recurrent pregnancy loss Recurrent miscarriage is three or more consecutive pregnancy losses. In contrast, infertility is the inability to conceive. In many cases the cause of RPL is unknown. After three or more losses, a thorough evaluation is recommended by American S ...

. Accordingly, the condition may be a variation or a pathology. One view maintains that the condition is associated with a higher risk for

miscarriage Miscarriage, also known in medical terms as a spontaneous abortion and pregnancy loss, is the death of an embryo or fetus before it is able to survive independently. Miscarriage before 6 weeks of gestation is defined by ESHRE as biochemical lo ...

premature birth Preterm birth, also known as premature birth, is the birth of a baby at fewer than 37 weeks gestational age, as opposed to full-term delivery at approximately 40 weeks. Extreme preterm is less than 28 weeks, very early preterm birth is between 2 ...

, and

malpresentation In obstetrics, the presentation of a fetus about to be born specifies which anatomical part of the fetus is leading, that is, is closest to the pelvic inlet of the birth canal. According to the leading part, this is identified as a cephalic, b ...

. Thus a study that evaluated women with uterine bleeding by hysteroscopy found that 6.5% of subjects displayed the arcuate uterus and had evidence of reproductive impairments. A study based on hysterosalpingraphic detected arcuate lesions documented increased fetal loss and obstetrical complications as a risk for affected women. Woelfer found that the miscarriage risk is more pronounced in the second trimester. In contrast, a study utilizing 3-D ultrasonography to document the prevalence of the arcuate uterus in a gynecological population found no evidence of increased risk of reproductive loss; in this study 3.1% of women had an arcuate uterus making it the most common uterine anomaly; this prevalence was similar than in women undergoing sterilization and lower than in women with recurrent pregnancy loss.

Cause

The uterus is formed during

embryogenesis An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm ...

by the fusion of the two

Müllerian duct Paramesonephric ducts (or Müllerian ducts) are paired ducts of the embryo that run down the lateral sides of the genital ridge and terminate at the sinus tubercle in the primitive urogenital sinus. In the female, they will develop to form the fal ...

s. During this fusion a resorption process eliminates the partition between the two ducts to create a single cavity. This process begins caudally and advances cranially, thus an arcuate uterus represents an in the final stage incomplete absorption process.

Diagnosis

A transvaginal ultrasound can reveal the condition. Helpful techniques to investigate the uterine structure are

transvaginal ultrasonography Vaginal ultrasonography is a medical ultrasonography that applies an ultrasound transducer (or "probe") in the vagina to visualize organs within the pelvic cavity. It is also called transvaginal ultrasonography because the ultrasound waves go '' ...

and

sonohysterography Gynecologic ultrasonography or gynecologic sonography refers to the application of medical ultrasonography to the female pelvic organs (specifically the uterus, the ovaries, and the fallopian tubes) as well as the bladder, the adnexa, and the rec ...

hysterosalpingography Hysterosalpingography (HSG), also known as uterosalpingography, is a radiologic procedure to investigate the shape of the uterine cavity and the shape and patency of the Fallopian tubes. It is a special x-ray using dye to look at the womb (uter ...

MRI Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...

, and

hysteroscopy Hysteroscopy is the inspection of the uterine cavity by endoscopy with access through the cervix. It allows for the diagnosis of intrauterine pathology and serves as a method for surgical intervention (operative hysteroscopy). Hysteroscope A hyst ...

. More recently 3-D ultrasonography has been advocated as an excellent non-invasive method to delineate the condition.

Differential diagnosis

The major differential diagnosis is the uterine septum. The lack of agreement to separate these two entities makes it difficult to assess the results in the literature.

Management

Many patients with an arcuate uterus will not experience any reproductive problems and do not require any surgery. In patients with recurrent pregnancy loss thought to be caused by an arcuate uterus hysteroscopic resection can be performed.

Epidemiology

Most studies of

uterine malformation A uterine malformation is a type of female genital malformation resulting from an abnormal development of the Müllerian duct(s) during embryogenesis. Symptoms range from amenorrhea, infertility, recurrent pregnancy loss, and pain, to normal func ...

s are based on populations of women who have experienced a

and thus do not address the issue of the prevalence in the general population. A screening study by Woelfer et al. of women without a history of reproductive problems found that about 5% of women had an arcuate uterus when they defined an arcuate uterus any fundal protrusion into the cavity that had an apical angle of more than 90 degrees. Accordingly, it was the most common uterine anomaly, followed by

(3%) and

bicornuate uterus A bicornuate uterus or bicornate uterus (from the Latin ''cornū'', meaning "horn"), is a type of mullerian anomaly in the human uterus, where there is a deep indentation at the fundus (top) of the uterus. Pathophysiology A bicornuate uterus ...

(0.5%).

References

External links

{{DEFAULTSORT:Arcuate Uterus Anatomical pathology Congenital disorders of female genital organs