Arcuate uterus uterus is a type of two-horned uterus; a malformation in which the bottom of the uterus is split in the form of a saddle. The degree of splitting of the uterine fundus into two horns varies, but in all cases the shape of the uterus in the section resembles a saddle. The presence may not manifest any disorders or be accompanied by an increased threat of miscarriage, premature birth, weakness and discoordination of labor, postpartum bleeding. Arcuate uterus is often combined with other malformations. Disease is detected, as a rule, accidentally – during ultrasound, hysteroscopy. Surgical correction is indicated in case of violation of gestation.
Arcuate uterus is a particular manifestation of the bicornuate uterus. With arcuate uterus, a small concave depression in the form of a saddle is formed on the outer surface of the bottom of the organ. In gynecology, out of the total number of uterine abnormalities, the arcuate uterus accounts for about 23% of cases. The degree of splitting of the uterine fundus into two horns can be different: expansion of the transverse size, flattening of the bottom, weak divergence of the bottom into two horns. In all cases, the shape of the uterus in the section resembles a saddle.
Disease is often combined with defects of the urinary system, septate uterus, narrow pelvis. Therefore, the presence of arcuate uterus can be dangerous for the development of primary infertility, various pathologies of pregnancy, birth injuries, postpartum complications, stillbirth.
Pathology is formed in the period between 10-14 weeks of embryogenesis during the fusion of mesonephral ducts. At the stage of embryonic development, the uterine cavity is initially represented by two utero-vaginal cavities separated by a median sagittal septum. By the time of the birth of the female fetus, the septum gradually resolves, i.e. initially the bicornuate uterus first takes arcuate uterus, and then a normal, pear-shaped single-cavity. In cases of incompleteness of the processes of uterine formation by the time of the girl’s birth, concavity in the bottom area persists, which leads to a congenital defect – saddle uterus. In addition to splitting the bottom with an arcuate uterus uterus, there is always its expansion in diameter.
The causes of dysembriogenesis and the formation of the arcuate uterus can be various damaging factors that disrupt the proper formation of organs during pregnancy: maternal intoxication (alcohol, nicotine, narcotic, medicinal, chemical), vitamin deficiency, stress, endocrinopathy (thyrotoxicosis, diabetes mellitus), heart defects. Infectious diseases of a pregnant woman – measles, influenza, rubella, syphilis, toxoplasmosis, etc. – have an extremely unfavorable effect on organogenesis. Pregnancy in conditions of toxicosis, chronic fetal hypoxia can contribute to the formation of an arcuate uterus.
Outside of pregnancy, a woman may not guess about the presence of a saddle uterus. A slight arcuate uterus fundus does not prevent the onset of pregnancy, does not complicate fetal gestation and childbirth. With more pronounced changes, there may be a threat of spontaneous termination of pregnancy, pathology of the placenta (lateral or low location, placenta previa, premature detachment), transverse fetal position, pelvic presentation of the fetus, premature birth.
During childbirth, the arcuate uterus uterus may be a factor in the development of abnormal labor activity – weakness or discoordination. Often, with an arcuate uterus in obstetrics, it is necessary to resort to cesarean section. Anatomical and functional inferiority of the uterus can provoke postpartum bleeding. In the absence of proper monitoring of a woman during pregnancy, the risk of perinatal mortality increases. In cases of severe deformation of the uterine fundus, primary infertility may be observed.
Instrumental studies – ultrasound, hysteroscopy, hysterosalpingography, magnetic resonance imaging – play a crucial role in the diagnosis of the saddle uterus. A standard gynecological examination with a saddle uterus is uninformative.
In the process of pelvic echography (ultrasound), the saddle uterus is not always detected. With significant deformation, transverse scanning reveals an increase in the width of the uterine fundus to 68 mm, thickening of the myometrium of the fundus wall to 10-14 mm and its bulging into the organ cavity. To detect the arcuate uterus, ultrasound is preferable to carry out with a vaginal sensor in the second phase of the cycle with a sufficiently pronounced thickness of the endometrium.
The most reliably characteristic signs of arcuate uterus are found during hysterosalpingography: 2 mouths of the fallopian tubes are determined on radiographs, a small depression in the form of a saddle is clearly visible in the bottom area, extending into the uterine cavity. Similar signs are detected during MRI. Hysteroscopy is used for direct visual examination of the uterine cavity. In the course of pregnancy management in patients with arcuate uterus, dopplerography of uteroplacental blood flow is monitored, cardiotocography, phonocardiography of the fetus is performed.
Surgical tactics for arcuate uterus are used only if conception is impossible (in the absence of other reasons) or the usual miscarriage of the fetus. Reconstruction of the uterine cavity is more often performed during hysteroscopy through natural pathways, without incisions. After correcting the defect, the chances of a normal pregnancy increase tenfold.
Patients with arcuate uterus should be under the close supervision of an obstetrician-gynecologist from the early stages of pregnancy, strictly follow all recommendations, and if the slightest violations occur, be hospitalized in a maternity hospital. In case of complicated pregnancy in patients with arcuate uterus, bed rest, antispasmodics, herbal sedatives, progestogens, deproteinized hemoderivate of calves’ blood, essential phospholipids are prescribed. Tactics regarding the upcoming birth in pregnant women with arcuate uterus are decided in advance.