Oligohydramnios sequence represents the description of the effects of insufficient amniotic fluid production. These are severe malformations that develop due to low amniotic fluid volumes during embryogenesis. The condition is fatal.
What is an oligohydramnios sequence?
Oligohydramnios sequence refers to the effects of insufficient amniotic fluid production during pregnancy. Due to constricted space because of low amniotic fluid, the embryo cannot develop normally. Severe malformations of the internal and external organs occur. Initially, the syndrome was described by the American pathologist Edith Potter in bilateral absence of kidneys (bilateral renal agenesis). Therefore, it is also called Potter syndrome. Potter performed about 5000 autopsies on 3 female and 17 male embryos or newborns. However, since the malformations are not limited to the absence of kidneys, it is referred to as oligohydramnios sequence. The lack of amniotic fluid during pregnancy is also called oligohydramnios. By definition, this is when the amount of amniotic fluid is less than 200 to 500 ml. The amniotic fluid index is less than 5.1 cm or the amniotic fluid deposits are less than 2 cm between the placenta (placenta), uterine wall and fetus. Oligohydramnios occurs in up to four percent of pregnancies and can have several causes. Rarely does it develop into an oligohydramnios sequence.
Causes
The cause of an oligohydramnios sequence is insufficient amniotic fluid. Most commonly, premature rupture of the membranes results in loss of amniotic fluid. However, this is not the cause of an oligohydramnios sequence because the amniotic fluid loss here happens just before birth. The oligohydramnios sequence can only develop if there is a long-term oligohydramnios. This mainly results from decreased urine production by the embryo. Furthermore, severe growth retardation of the baby can lead to it. Dysfunction of the placenta due to high blood pressure or nicotine consumption also sometimes causes oligohydramnios. Other causes can be obstructive urinary tract diseases or chromosomal aberrations. As a result of insufficient amniotic fluid, there is a lack of space for the embryo, as it can only develop within the amniotic fluid. These constricted space conditions result in abnormal growth conditions for the fetus. All malformations are due to this. However, in some cases, pre-existing malformations of the kidneys or urinary tract may also limit urine production and excretion. This results in decreased amniotic fluid production, which in turn impedes the development of the remaining organs. Overall, it is therefore not entirely clear whether the clinical picture of the oligohydramnios sequence can also be genetically determined or is really only due to growth disorders caused by the oligohydramnios. It is also possible that there are multiple causes.
Symptoms, complaints, and signs
The oligohydramnios sequence is characterized by severe internal and external dysplasia. The most important symptom is malformation of the genitourinary tract. In particular, both kidneys are affected. Either they are completely absent (renal agenesis) or they are severely underdeveloped. In addition, there is hypoplasia (underactivity) of the lungs. In addition to clubfeet, there may be other malformations of the extremities or the spine. Particularly striking are the malformations of the face, known as Potter facies. These dysmorphias are similar to those seen in Down syndrome. The auricles are particularly shaped in low-set and flat ears. The cartilage substance of the auricles is missing. Another symptom is an epicanthus medialis. This is a double fold of the eyelid similar to the Mongolian fold at the inner edge angle of the eye. In addition, the interocular distance is comparatively large, and this is referred to as hypertelorism. Finally, the lower jaw is underdeveloped. It therefore appears shortened. The prognosis of the disease is very poor. Due to renal agenesis alone, death occurs either before the child is born or shortly thereafter.
Diagnosis and course of the disease
Potter syndrome or oligohydramnios sequence can be diagnosed prenatally during a prenatal ultrasound examination.From the 17th week of pregnancy, a Potter’s syndrome is clearly recognizable. In this case, it can be detected by the significant growth retardation and the unusual forced posture due to the lack of space caused by the absence of amniotic fluid.
Complications
Due to the oligohydramnios sequence, the children suffer from very severe malformations and deformities. In severe cases, the children may be born dead or even die shortly after birth. As a rule, the parents and relatives of the child also suffer from severe psychological symptoms and depression. Furthermore, the kidneys can be completely missing in the patient, so that the child is directly dependent on dialysis. Down’s syndrome can also occur and significantly reduce the quality of life of the affected person. The lower jaw is shortened and there are also hearing difficulties and impaired vision. In most cases, however, the child dies shortly after birth as a result of the oligohydramnios sequence. Unfortunately, treatment of oligohydramnios sequence after birth is not possible. However, the condition can be diagnosed relatively early, so early treatment of this condition is also possible. The deficits of the amniotic fluid can be compensated, so that the malformations can be avoided. For the mother, the oligohydramnios sequence does not pose any health risk and there is no reduction in life expectancy.
When should you go to the doctor?
The far-reaching consequences of amniotic fluid deficiency are dramatic for the expectant child. Numerous malformations occur, as a result of which the child dies. The possible causative factors of an oligohydramnios sequence are not clear, multi-causal causes are suggested. Although an oligohydramnios sequence can be diagnosed prenatally and during routine ultrasound examination. However, the presence of an oligohydramnios sequence is not detectable until after the 17th week of gestation. By then, however, it is too late to terminate the pregnancy. However, if the gynecologist recognizes the amniotic fluid deficiency in time, it can be compensated. In this case, the child will probably be born healthy or with only minor consequential damage. In the presence of a pronounced oligohydramnios sequence, the unborn child often dies before birth. Sometimes it dies shortly afterwards. The affected child has suffered such severe damage due to the lack of space in the amniotic sac that it would not be able to survive even with the best medical help. In some cases, the children are born alive but with severe kidney damage. They are immediately in need of dialysis. Such children learn that doctor visits are part of their short lives.
Treatment and therapy
Unfortunately, therapy is no longer possible in a pronounced oligohydramnios sequence. The prognosis is 100 percent fatal. If the infant is not already stillborn, he or she will die within a short time because of the renal and pulmonary malformations. However, the precipitating cause of the oligohydramnios sequence (the oligohydramnios) can be treated during pregnancy. Oligohydramnios, as mentioned earlier, is characterized by decreased amniotic fluid volume. Evidence of this comes from an unusually small uterus and reduced fetal movement. This already indicates constricted space. Sometimes it is sufficient for the pregnant woman to drink enough to return the amount of amniotic fluid to normal. This is the case when only temporary causes have led to the amniotic fluid reduction. However, if the amount of amniotic fluid cannot be compensated by drinking, maldevelopment of the child is to be expected. In this case, there is still the possibility of compensating for the amniotic fluid quantity by means of an amniotic infusion. An amniotic fluid infusion is an external replenishment of amniotic fluid. A catheter or needle is used to fill the amniotic fluid with a glucose-saline solution. This procedure is performed under ultrasound guidance. However, if the child’s general condition is poor, the method of choice is premature delivery of the child. However, lung maturation induction should be arranged beforehand.
Prospect and prognosis
If an insufficient amount of amniotic fluid is produced in a pregnancy, it can be a death sentence for the embryo. An insufficient amount of amniotic fluid means that the unborn baby cannot develop properly.It would suffer from severe malformations due to the oligohydramnion sequence, or die at birth. Obviously, the oligohydramnios sequence is multifactorial. Most children with malformations and sequelae caused by it die at birth or a short time later. Those who survive longer are severely damaged and malformed in many organ systems and limbs. Among other things, the kidneys are missing. This alone prevents many of the children from surviving. The survivors are dependent on dialysis. They also have severe deformities in other ways. Nowadays, however, prenatal examinations can determine whether or not there is enough amniotic fluid. If a deficiency is found, the amount of amniotic fluid can be increased. This can prevent the serious sequelae caused by the oligohydramnios sequence. However, it is problematic that this examination only makes sense after the 17th week of pregnancy, because the doctors cannot detect the amniotic fluid deficiency before then. It is then already too late for an abortion. However, if the amniotic fluid deficiency is detected at this stage, most children can be born healthy with a good prognosis. Some have mild malformations.
Prevention
To prevent an oligohydramnios sequence, constant attention must be paid to adequate amniotic fluid during pregnancy. If signs of oligohydramnios develop, appropriate measures to replenish the amniotic fluid should be taken immediately.
What you can do yourself
Because oligohydramnios is a fatal condition, there is very little that can be done to help yourself. To prevent oligohydramnios sequence, constant attention must be paid to a sufficiently high amniotic fluid volume during pregnancy. Sometimes it is sufficient for the pregnant woman to compensate for increased fluid loss by drinking. If an oligohydramnios sequence has already been diagnosed, the life expectancy of the unborn child is already very low due to possible lung and kidney damage. As this is an exceptional psychological situation for the parents and relatives, it is important to offer sufficient support services. As a person affected, it can help to open up to such offers of support, which are often offered by hospitals and psychological services. One’s own social environment should also not be neglected in such a situation. An intact social environment can help to cope with the stresses of an oligohydramnios sequence and its consequences. First signs of depression should be taken seriously and responded to. Alternative therapies and relaxation methods such as yoga and meditation can also help to find new courage to face life during the difficult time of one’s own or a relative’s illness.
