Congenital uterine anomalies are changes in the location, shape, size, or proportions of an organ that occur as a result of developmental disorders in the prenatal period. It is often accompanied by functional disorders of the reproductive system, can be combined with malformations of other genitals. Infertility, miscarriage and pregnancy complications are possible. In some cases, congenital uterine anomalies are asymptomatic. The diagnosis is made taking into account complaints, anamnesis, results of gynecological examination and additional research data. Therapeutic tactics are determined depending on the type and severity of the defect.
Q51 Congenital anomalies [malformations] of the development of the body and cervix
Congenital uterine anomalies – changes in the anatomical structure of the organ due to disorders of intrauterine development. They make up 1-2% of the total number of congenital anomalies of the female genital organs. They differ significantly in the manifestations and degree of functional disorders. They are often combined with malformations of the vagina and fallopian tubes. Uterine abnormalities often occur asymptomatically and are detected only during ultrasound or gynecological examination. They can provoke menstrual disorders, cause infertility and miscarriage. They increase the likelihood of complications of pregnancy and childbirth. Treatment of congenital uterine anomalies development is carried out by specialists in the field of operative gynecology.
Congenital uterine anomalies development occur under the influence of adverse factors during various periods of pregnancy. The type and severity of the birth defect depends on the time of exposure. Among the unfavorable factors provoking abnormalities of the development of the uterus in a female fetus include:
- bacterial and viral infections of a pregnant woman;
- endocrine and somatic diseases;
- exchange violations;
- genetic abnormalities;
- occupational hazards;
- taking certain medications;
- drug addiction, alcoholism;
- severe psychological stress;
- poor environmental conditions.
The uterus is formed from the middle part of the paired Muller channels that have merged with each other. Channels are formed in the first month of pregnancy, their fusion occurs during the second month of pregnancy. At the same time, the lower parts of the channels also merge, forming a vagina, and the upper ones remain disconnected and subsequently transform into fallopian tubes. Violation of the fusion process entails all possible variants of abnormalities in the development of the uterus in the form of partial or complete duplication. It is also possible that one of the channels is underdeveloped with a corresponding asymmetry of the organ. A fairly common pathology is the general underdevelopment of the uterus, due to later effects on the process of mutual regulation of the maturing endocrine and reproductive systems of the fetus.
Symptoms of uterine abnormalities
One – horned uterus
It is formed when the growth of one Muller duct stops or slows down and the other develops normally. It is approximately 13% of the total number of uterine abnormalities caused by a violation of the development of the Muller ducts. In almost half of cases, it is combined with congenital defects of the urinary system. There are four main variants of this anomaly of uterine development: without a rudimentary horn; with a horn without a cavity; with a horn whose cavity communicates with the uterine cavity; with a horn having an isolated cavity.
Usually accompanied by primary algomenorrhea. Amenorrhea or uterine bleeding are possible. Some patients with this abnormality of uterine development complain of soreness during sexual intercourse. Infertility is observed in some patients. In other women, pregnancy is possible, but the outcome of gestation depends on the size of the uterus. According to statistics, in half of cases pregnancy ends with spontaneous abortion.
Premature birth is observed in 15% of patients with this abnormality of uterine development. The survival rate of the fetus is approximately 40%. Intrauterine development delay and incorrect presentation are often diagnosed. Emergency conditions with a one-horned uterus can occur when blood accumulates in the horn that does not communicate with the uterine cavity. Another danger of this abnormality of uterine development is pregnancy in a rudimentary horn. Due to the small size of the horn, such a pregnancy ends with a rupture of the uterus and massive bleeding.
Two – horned uterus
It is formed with incomplete fusion of the middle part of the Muller ducts. It has two cavities and one neck, less often – two necks connecting with one normal vagina or with a vagina separated by a partial septum. In 20% of cases of abnormal uterine development, a complete two–horned uterus is detected – an organ with two separate cavities. An incomplete two-horned uterus resembles a symbolic image of the heart, has a common cavity and a modified bottom, separated by a more or less pronounced protrusion.
Saddle – shaped uterus
It makes up 23% of the total number of abnormalities in the development of the uterus, it is an organ with a saddle-shaped depression in the bottom area. It can be separated by a full or partial intrauterine septum. It often proceeds asymptomatically. Some patients have a normal course of pregnancy and a successful delivery. In other cases, with this abnormality of uterine development, miscarriage of pregnancy, pelvic presentation of the fetus, pathology of the placenta, premature birth, weak or discoordinated labor activity is observed.
Doubling of the uterus and vagina
Refers to cases of duplication of female genitalia. A more common variant of this abnormality of uterine development is the simultaneous doubling of the uterus and vagina, less often two uterus are detected with a common vagina. Organs usually come into more or less close contact with each other or partially fuse, but cases of queens separated by a bladder have been described. The degree of maturity of organs with this abnormality of uterine development can vary significantly – from two equally mature uterus and vaginas on both sides to extremely uneven development (a full pair of organs on the one hand and rudimentary on the other). With sufficient development of both pairs of organs, menstruation and pregnancy can occur in both one and the other uterus.
Agenesis (complete absence of the uterus) is a rare pathology and is mainly diagnosed by opening non-viable fetuses with multiple birth defects. Uterine hypoplasia is a fairly common anomaly, it can be combined with other manifestations of infantilism or be an isolated pathology. A proportional reduction in the size of the body and cervix is possible, or a reduction in the body in combination with an elongation of the cervix.
It is often accompanied by a violation of the position of the uterus (pathological bending anteriorly or posteriorly). Patients with this abnormality of uterine development may complain of algomenorrhea and amenorrhea. There are three forms of this abnormality of uterine development:
- small or hypoplastic (the length of the organ is about 8 cm, the ratio of the body and neck is not broken);
- infantile (the length of the organ is more than 3 cm, the neck is elongated);
- rudimentary (the length of the organ is less than 3 cm, the length of the cervix is more than half of the total length of the uterus). A rudimentary uterus can be functioning or non-functioning.
Sometimes, with this abnormality of uterine development, there is a lack of a cervix or cervical canal.
The type of anomaly is determined on the basis of a gynecological examination and additional research data. To clarify the features of the abnormality of uterine development, invasive studies are used – hysteroscopy and laparoscopy, which make it possible to assess the shape, volume and condition of the internal cavity of the uterus, determine the structure, identify concomitant pathology of the fallopian tubes and other disorders. A modern alternative to invasive research is non-traumatic MRI and ultrasound with high resolution.
Treatment of uterine malformations
The tactics of treatment of congenital uterine anomalies development is determined by the gynecologist individually, taking into account the type and severity of the anomaly, the age and condition of the patient’s body, her desire to have children and other factors. Indications for emergency surgery are pregnancy in a rudimentary uterine horn, accumulation of menstrual blood in an atresized vagina or in an isolated cavity of the uterine horn.
Indications for elective surgery for congenital uterine anomalies development are usually violations of childbearing function (miscarriage, infertility). With a one-horned uterus, the rudimentary horn is removed, followed by fixation of the fallopian tube to the corner of the uterus. With a double and two-horned uterus, the walls of the organ are dissected along the inner rib, and then connected, forming a single cavity. Surgical intervention is usually performed through open access (Strassmann operation), less often – using hysteroscopy. With a saddle uterus, metroplasty is usually performed through natural pathways during hysteroscopy.
The prognosis is determined by the type of pathology, the degree of maturity of the uterus and the volume of the organ cavity. There is an increased threat of spontaneous abortion, miscarriage and premature birth. The management of pregnancy with congenital uterine anomalies development includes the prevention of miscarriage, the development of bleeding and isthmic-cervical insufficiency. If there is a threat of termination of pregnancy after 26 weeks, a caesarean section is indicated.
In other cases, the tactics of obstetric care for congenital uterine anomalies development is determined taking into account the position and condition of the fetus, the presence of endocrine and somatic diseases in the mother and other factors. Surgical interventions can increase the probability of successful pregnancy from 30-40 to 90 percent or more. Women with congenital uterine anomalies development, who previously complained of painful menstruation and a violation of the general condition during menstruation, note the disappearance of pain and improvement of well-being.
In case of gross congenital uterine anomalies development and miscarriage of pregnancy, a woman may resort to the use of surrogate motherhood. Artificial insemination by ICSI, IMSI or PICSI is carried out with the participation of the patient’s own egg and her husband’s sperm (or donor sperm). Then the embryos are cultured. After the selection and full examination of the surrogate mother, the embryos are transplanted into her uterus.