Abdominal pregnancy is a pregnancy in which the fetal egg is implanted not in the uterus, but in the abdominal cavity. Risk factors are inflammatory diseases of the appendages, operations on reproductive organs, prolonged use of the intrauterine device, genital infantilism, pelvic tumors, endocrine disorders and stress. According to its manifestations before complications, abdominal pregnancy resembles normal gestation. There is a high probability of internal bleeding and damage to the abdominal organs. The diagnosis is made on the basis of complaints, anamnesis, general and gynecological examination data and the results of instrumental studies. The treatment is operative.
Abdominal pregnancy is a pregnancy in which the embryo is implanted not in the uterine cavity, but in the area of the omentum, peritoneum or on the surface of the abdominal organs. It is 0.3-0.4% of the total number of ectopic pregnancies. Risk factors for the development of abdominal pregnancy are pathological changes in the reproductive system, age, stress and endocrine disorders. The outcome depends on the location of the implantation of the fetal egg, the level of blood supply and the presence of large vessels in the area of implantation of the embryo. Fetal death, damage to large vessels and internal organs are possible. Abdominal pregnancy is an indication for urgent surgical intervention. The treatment of this pathology is carried out by obstetricians and gynecologists.
The sperm penetrates into the egg in the ampullary part of the fallopian tube. As a result of the introduction, a zygote is formed, covered with a shiny egg shell. Then the zygote begins to divide and simultaneously moves along the fallopian tube under the influence of peristaltic contractions and vibrations of the cilia of the tubal epithelium. In this case, the undifferentiated cells of the embryo are held by a common shiny shell. Then the cells are divided into two layers: the inner (embryoblast) and the outer (trophoblast). The embryo enters the blastocyst stage, enters the uterine cavity and “sheds” the shiny shell. The villi of the trophoblast sink deep into the endometrium – implantation takes place.
Abdominal pregnancy occurs in two cases. The first is if the fetal egg is in the abdominal cavity at the time of implantation (primary abdominal pregnancy). The second is if the embryo is first implanted in the fallopian tube, then rejected by the type of tubal abortion, enters the abdominal cavity and is re–implanted on the surface of the peritoneum, omentum, liver, ovary, uterus, intestine or spleen (secondary abdominal pregnancy). It is often not possible to distinguish between the primary and secondary forms, since a scar is formed at the site of primary implantation after rejection of the embryo, which is not detected during standard studies.
Risk factors for the development of abdominal pregnancy are inflammatory diseases of the ovaries and fallopian tubes, adhesions and contractility disorders of the tubes as a result of surgical interventions, lengthening of the tubes and slowing down of tubal peristalsis in genital infantilism, mechanical compression of the tubes by tumors, endometriosis of the fallopian tubes, IVF and prolonged use of the intrauterine device. In addition, the likelihood of abdominal pregnancy increases with diseases of the adrenal glands and thyroid gland and with an increase in the level of progesterone, which slows down tubal peristalsis. Some authors point to a possible connection between abdominal pregnancy and premature activation of the trophoblast.
In women who smoke, the risk of abdominal pregnancy is 1.5-3.5 times higher than in non-smokers. This is due to a decrease in immunity, impaired peristaltic movements of the fallopian tubes and delayed ovulation. Some researchers point to a link between abdominal pregnancy and stress. Stressful situations negatively affect the contractile activity of the fallopian tubes, causing antiperistaltic contractions, as a result of which the embryo is delayed in the tube, attached to its wall, and then after a tubal abortion is re-implanted in the abdominal cavity.
In recent decades, the problem of ectopic pregnancy (including abdominal pregnancy) in women of late reproductive age has become increasingly urgent. The need to build a career, improve their social and financial situation encourages women to postpone the birth of a child. Meanwhile, the hormonal background changes with age, the peristalsis of the tubes becomes less active, various neurovegetative disorders occur. In women over 35 years of age, the risk of developing abdominal pregnancy is 3-4 times higher than in women under the age of 24-25 years.
The course of abdominal pregnancy depends on the characteristics of the place of attachment of the embryo. When implanted in an area with poor blood supply, the fetus dies. When attached in a place with an extensive network of small vessels, the embryo can continue to develop, as with normal gestation. At the same time, the probability of congenital malformations during abdominal pregnancy is much higher than during normal gestation, since the fetus is not protected by the uterine wall. Abdominal pregnancy is extremely rare to be carried to the due date. When large vessels germinate with chorionic villi, massive internal bleeding occurs. Invasion of the placenta into the tissue of parenchymal and hollow organs causes damage to these organs.
Before complications occur in abdominal pregnancy, the same symptoms are detected as in normal gestation. In the early stages, nausea, weakness, drowsiness, changes in taste and olfactory sensations, absence of menstruation and swelling of the mammary glands are observed. During a gynecological examination, it is sometimes possible to find that the fetus is not in the uterus, and the uterus itself is slightly enlarged and does not correspond to the gestation period. In some cases, the clinical picture of abdominal pregnancy is not recognized, but interpreted as a multiple pregnancy, pregnancy with a myomatous node or congenital abnormalities of the uterus.
Subsequently, a patient with abdominal pregnancy may complain of pain in the lower abdomen. When small vessels are damaged, increasing anemia is observed. Clinical manifestations of internal organ damage are highly variable. Sometimes such complications in abdominal pregnancy are mistaken for the threat of rupture of the uterus, premature detachment of the placenta or the threat of termination of gestation. Pronounced weakness, dizziness, fainting, loss of consciousness, darkening of the eyes, excessive sweating, pain in the lower abdomen, pallor of the skin and mucous membranes indicate the development of internal bleeding – an emergency pathology that poses an immediate danger to the life of a pregnant woman.
Diagnosis and treatment
Early diagnosis is extremely important because it allows you to avoid the development of dangerous complications, eliminate the threat to the life and health of the patient. The diagnosis is established on the basis of gynecological examination data and ultrasound results. To avoid diagnostic errors, the study begins with the identification of the cervix, then the “empty” uterus and the fetal egg located away from the uterus are visualized. During ultrasound in the late stages of abdominal pregnancy, an unusual localization of the placenta is detected. The fetus and placenta are not surrounded by the walls of the uterus.
In doubtful cases, laparoscopy is performed – a minimally invasive therapeutic and diagnostic intervention that allows to reliably confirm abdominal pregnancy and in some cases (in the early stages of gestation) to remove the fetal egg without performing a volumetric operation. In the later stages, when placental villi germinate into the abdominal organs, laparotomy is required. The volume of surgical intervention in abdominal pregnancy is determined by the localization of the placenta. It may require suturing or resection of the organ, the imposition of intestinal anastomosis, etc.
The prognosis for the mother with early detection and timely surgical treatment is usually favorable. With late diagnosis and the development of complications, there is a very high risk of an unfavorable outcome (death as a result of bleeding, severe damage to internal organs). The probability of successful completion of abdominal pregnancy is extremely low. The literature describes isolated cases of successful surgical delivery at late gestation, however, such an outcome is considered as casuistic. It is noted that infants born as a result of abdominal pregnancy often have developmental abnormalities.