Hydrops Fetalis

Comprehensive Guide to Hydrops Fetalis

Hydrops fetalis refers to fluid accumulation in multiple fetal compartments, serous cavities, or soft tissues. It is a serious symptom of various congenital diseases that cause anemia in the fetus. Hydrops fetalis can be diagnosed sonographically.

What is hydrops fetalis?

According to abbreviationfinder, hydrops fetalis is a term used in prenatal diagnosis and describes a generalized accumulation of fluid in the fetus. The fluid or edema is located in at least two fetal compartments, in serous body cavities such as the pleura, peritoneal cavity and pericardium, or in the soft tissues.

The edema may have spread over large parts of the unborn child’s body. Hydrops fetalis occurs with a frequency of 1:1500 to 1:4000 pregnancies. Depending on the cause, a distinction is made between immunological and non-immunological hydrops fetalis, but an assignment is only possible in about 50 percent of cases.

Since the occurrence of fluid accumulation in the child indicates a chromosome peculiarity, an organic malformation or a serious disease of the fetus, hydrops fetalis is one of the sonographic soft markers during pregnancy. These can be used to diagnose serious illnesses in the child even prenatally.


Fetal anemia is almost always the cause of hydrops fetalis. This results in hypoxic damage to the capillary walls, which increases their permeability and allows fluid to flow from the intravascular space into the extravascular space. These anemias can be immunological or non-immunological.

One of the immunological causes is Rhesus incompatibility between mother and child. This leads to massive haemolysis and anemia in the unborn child in the second mother. Rarer immunological causes include fetofetal transfusion syndrome and thalassemia.

In the meantime, predominantly non-immunological causes cause hydrops fetalis. Congenital malformations of the heart often result in fetal anemia. Increasing cardiac output to compensate for anemia can result in heart failure and increased fluid retention.

Infections with toxoplasmosis, syphilis connata, ringworm or cytomegalovirus are also among the non-immunological causes. Furthermore, hydrops fetalis is frequently observed in a number of diseases such as Turner syndrome, trisomy 18 or Down syndrome.

Symptoms, Ailments & Signs

The unborn child shows fluid accumulation or edema in the fetal compartments, the serous cavities or in the soft tissues. The most common are ascites, pleural effusions and polyhydramnios.

Ascites is the accumulation of water in the abdominal cavity. The pleura is a two-sheeted membrane that encases the lungs and lines the thorax. A pleural effusion is a buildup of fluid in the small space between the lungs and the chest wall.

Polyhydramnios refers to an above-average amount of amniotic fluid with an amniotic fluid index of over 20 centimeters or an amniotic fluid depot of more than eight centimeters. The accumulation of fluid in the soft tissues occurs relatively early.

In most cases, the fetus shows a pumping weakness of the heart with an increased cardiac output. After birth, the children suffer from increased neonatal jaundice; the anemia and edema are still present.

Diagnosis & disease progression

The presence of hydrops fetalis is determined intrauterine by ultrasound. The lifting of the skin from the body due to the edema is clearly recognizable in the child. If a risk factor for the development of fetal anemia is known, the pregnancy can be monitored by regular sonographic examinations in order to be able to counteract hydrops fetalis if necessary.

Blood samples from the umbilical cord can indicate anemia early on. A heart defect can be identified using echocardiography. Thanks to modern diagnosis and therapy options, around 85 percent of children can survive hydrops fetalis of immunological origin. However, if there is a non-immunological cause, the fetal mortality rate is over 80 percent.


Hydrops fetalis can cause various symptoms. In many cases, the disease affects the fetus. The affected person suffers from a so-called abdominal dropsy, whereby water accumulates in the abdominal cavity. This accumulation can later lead to difficulty breathing and further to shortness of breath.

There is also accumulation of water in the soft tissues of the affected person. Hydrops fetalis puts a lot of strain on the heart, which can lead to damage and restrictions on the heart. The liver is also damaged, so most children are born with neonatal jaundice. If the symptoms are not treated, the patient usually dies prematurely.

The treatment of hydrops fetalis is causal and symptomatic in most cases. The symptoms can often be reduced by a blood transfusion. In serious cases, however, the termination of the pregnancy is necessary if the health of the mother is also endangered. After birth, children may need mechanical ventilation to survive. It is usually not possible to predict whether the course of the disease will be positive.

When should you go to the doctor?

The presence of hydrops fetalis is usually determined during ultrasound examinations during pregnancy. At the latest after birth, the disease can be recognized based on the typical external features. Whether further medical examinations are required after the diagnosis depends primarily on the severity of the disease. Slight accumulations of fluid sometimes go away on their own. In severe cases, treatment must be initiated during pregnancy.

Mothers who experience abdominal pain, possibly associated with unusual contractions in the baby, should speak to the gynecologist. If signs of a water belly become noticeable, the doctor must be consulted immediately. The disease must be clarified and treated immediately to rule out serious complications for mother and child. If the therapy is successful, no further treatments are required. However, the mother should continue to monitor any symptoms and, if not already done so, inform the obstetricians at the hospital about hydrops fetalis at the time of delivery. In this way, the child can be examined immediately after birth and, if necessary, given the appropriate medication.

Treatment & Therapy

Hydrops fetalis must be treated by eliminating the cause. As a rule, this is a fetal anemia that can be corrected intrauterine via the umbilical cord with blood transfusions. In feto-fetal transfusion syndrome during a twin pregnancy, the anastomoses in the twins’ blood circulation, which cause an uneven distribution of blood between the children, can be closed with laser photocoagulation.

If hydrops fetalis is the result of a cause with a poor prognosis, a medical consultation is necessary in order to discuss the therapeutic options, the consequences for the child and, above all, the risks for the mother with the parents. Under certain circumstances, an abortion for medical reasons must be considered.

If left untreated, hydrops fetalis not only has serious consequences for the child. In particularly severe cases, the mother can also develop symptoms that reflect hydrops fetalis. This clinical picture is called Maternal Hydrops Syndrome and is symptomatically very similar to severe preeclampsia.

Postnatally, children suffering from hydrops fetalis require intensive medical care. Children often require intubation and mechanical ventilation, receive blood transfusions, and are treated for jaundice with phototherapy or blood exchange. Ascites and pleural effusions are punctured for relief. The causative disease is then treated as far as possible.

Outlook & Forecast

The prognosis for hydrops fetalis is related to the cause of the water retention. If the fetus has a congenital disease or a chromosomal abnormality, it will be born with this underlying disease and it is possible that the visible water retention will not have receded by then. Depending on the health of mother and child, a section birth can make sense in such cases so that both do not injure themselves during the birth.

If, in addition to the hydrops fetalis, the child is diagnosed with such severe damage that it would only be born disabled or not viable at all, a late termination of the pregnancy can be considered. This is a very intimate and difficult decision, but it offers a way out of a life full of suffering and pain for the unborn child in the case of disease triggers with very poor prognosis. In the case of the common cause of fetal anemia, a blood transfusion can be administered via the umbilical cord in the womb, which significantly improves the baby’s prognosis.

Other triggers of hydrops fetalis can also be treated during pregnancy, so that the child is born as healthy as possible and, at best, even a natural delivery is possible if the woman wants this type of delivery and feels safe about it.


Whether hydrops fetalis can be prevented depends largely on the cause of the fetal anemia. In the case of congenital malformations, only close sonographic monitoring of the pregnancy helps in order to be able to intervene therapeutically at an early stage. Rhesus incompatibility can be counteracted by Rhesus prophylaxis during the first pregnancy.

The child’s erythrocytes in the mother’s blood are thus masked and broken down without the formation of antibodies. Vaccination protection or antibodies against infectious diseases should be checked even if you wish to have children.


It cannot generally be predicted whether special follow-up measures are available to those affected by hydrops fetalis, since these are highly dependent on the underlying disease. However, it is a serious illness that should definitely be diagnosed and treated by a doctor as soon as possible. It cannot heal on its own, and in the worst case the child can die if the hydrops fetalis is not treated.

In some cases, hydrops fetalis requires termination of the pregnancy. After such a termination, in most cases the parents need psychological support. Above all, the help and support of one’s own family or friends is very important in order to prevent depression and other mental disorders.

If the child survives the birth, it needs constant medical supervision. Even then, the parents are usually dependent on psychological support. The parents must strongly support the child in the further development in order to counteract damage and to avoid further complications. No general prediction can be made about the further life expectancy of the child.

You can do that yourself

Hydrops fetalis disease cannot be treated by self-help. In this case, a visit to a doctor is always necessary. If no treatment occurs, the unborn children can die of this disease. In some cases, a complete termination of the pregnancy must be carried out if the treatment would pose too high a risk for the mother.

For this reason, self-help is limited to the treatment of possible psychological complaints. Extensive discussions with your partner, family or, of course, friends can be very helpful in order to prevent or treat depression and other mental disorders. However, such discussions do not replace professional therapy by a therapist. If they are not helpful, a psychologist should be consulted.

Contact with other affected parents can also be helpful. This often leads to an exchange of information, which may improve the quality of life of those affected and thus make everyday life easier. It can also be worth visiting a self-help group to talk about the disease.

Hydrops Fetalis

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