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Pleural effusion - accumulation of fluid in the chest cavity Pericardial effusion
- accumulation of fluid around the heart Peritoneal effusion - accumulation of fluid
in the abdominal cavity Diffuse edema (fluid in the pleurae, peritoneum and/or around
or under the fetus's skin).
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Types
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Pleural effusion is an accumulation of fluid between the lungs and the external
wall of the chest cavity. This fluid can contain:
- In most cases, lymphatic fluid - this type is known as a chylothorax.
- Watery fluid (clear, serous and noninflammatory) - this is a hydrothorax.
- Blood - this is a hemothorax. This type is very rare and usually only occurs in
adults.
Pericardial effusion only is a relatively rare intrauterine condition. If there
is a pericardial effusion, its quantity is usually small and insignificant and the
condition is usually transient. The pericardial effusion, if present, is usually
part of a general condition of edema (clear, serous fluid) of the pleurae and peritoneum,
which can affect the rest of the body as well at a later stage.
Peritoneal effusion only is also rare in the fetus. Here too, most of the fluid
in the abdominal cavity is or will be part of a general condition of edema involving
the pleurae and possibly becoming more widespread later. Diffuse edema (ana sacra)
is an extreme example of this condition. Fluid accumulates in the subcutaneous (under
the skin) tissues of the fetus and is usually accompanied by an accumulation of
clear, serous fluid in the pleurae, peritoneum and pericardium.
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Clinical signs
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In chylothorax, the fluid is milky and contains a high concentration of lipids (triglycerides),
proteins and white blood cells (lymphocytes).
As long as the newborn has not eaten, for a short time after birth the fluid drained
from the chest cavity can appear clear in spite of containing these substances.
In half of these cases there is a spontaneous recovery over time, but until this
happens, the fluid must be continuously drained through a tube inserted into the
chest cavity.
Treatment in these cases is supportive.
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There have already been successes in inserting a drain, which contains a one-way
valve, into the fetus in utero, allowing for normal development of the lungs on
the side of the effusion.
The cause is usually not known, but these effusions can be associated with certain
chromosome disorders such as Turner syndrome or Down syndrome, etc., and chromosome
analysis should be performed. Effusions can also be associated with heart defects,
intrauterine infection and other defects - tests for these should also be carried
out as they may indicate the presence of a genetic syndrome.
Where there is watery (serous) fluid in the chest cavity and/or abdominal cavity
and/or diffuse edema, this is due to the accumulation of this fluid in many parts
of the body, starting with the chest cavity and progressing to the abdominal cavity
and subcutaneous tissues. This situation is known as diffuse edema. There are many
causes:
- Severe fetal anemia. This can be caused by:
- Blood group incompatibility of various types. Hemolytic anemia, which involves destruction
of the red blood corpuscles, can be identified in the fetus by the presence of maternal
antibodies that pass through the placenta into the fetal bloodstream. These antibodies
can be demonstrated in a blood test performed on the mother's blood, known as Coombs'
test, and in this situation the result in the mother will be positive. In order
to identify the exact type of incompatibility, it is important to examine other
parameters as well, such as the mother's and fetus's blood groups (ABO and rhesus),
and also the blood subtypes. Treatment involves a blood transfusion into the fetus
by injection into the fetus's abdominal cavity, and this can be repeated if necessary.
After birth, neonatologists care for the infant and if necessary will give a blood
transfusion in order to prevent jaundice of the newborn. In the past, the main cause
of fetal edema was rhesus incompatibility. Nowadays rhesus negative women are given
injections after the delivery of every baby and after every miscarriage in order
to prevent the development of anti-rhesus antibodies in the mother. These antibodies,
when present in the mother's blood and when they enter the fetus's bloodstream via
the placenta, destroy the fetus's blood cells. Because all rhesus negative women
are now treated, it is very rare nowadays for a fetus to be affected by rhesus incompatibility
problems, and therefore nowadays most diffuse edemas are not due to severe fetal
anemia.
- Viral infection by a parvovirus. This condition usually resolves without causing
defects. It can be demonstrated in the maternal bloodstream by testing for antibodies
to this virus.
- Heart defects.
- Threatened abortion.
- Non-parvovirus
intrauterine infection.
- Many diseases, such as various metabolic disorders.
- Various genetic syndromes such as
Noonan syndrome, etc.
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Inheritance pattern
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Depends on the type. Most problems are not hereditary.
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Penetrance
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Not known
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Associated features that can be demonstrated in tests performed during pregnancy
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In these cases,
chromosome disorders such as
Turner syndrome and Down syndrome,
etc., heart defects,
intrauterine infection
(including parvovirus) and other defects that may indicate the presence of a genetic
syndrome must be looked for. Chromosome analysis and fetal echocardiography should be carried
out as well as ultrasound examination. Blood group incompatibility must also be
investigated.
In all these cases it is important to refer the couple for genetic counseling, to
which they should bring all data, including the results of other tests performed
during the pregnancy such as alpha-fetoprotein, nuchal translucency, etc.
In the case of chylothorax only, the prognosis is usually good, and the condition
usually resolves after drainage and supportive therapy after birth. Conversely,
in the case of serous edema and diffuse edema, even if the results of all tests
are found to be normal, there is still an increased risk for syndromes that cannot
be detected in pregnancy tests. Therefore it is necessary to refer the parents to
a multidisciplinary clinic in a hospital for professional counseling by a geneticist,
an expert in ultrasound
examinations and/or a pediatric cardiologist, and a neonatologist, in order
to collate all the data and discuss the various risks in each specific case, the
method of monitoring the fetus, possible intervention if indicated, etc. The decisions
taken will depend on the severity of the problem, the presence of additional findings,
etc.
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What is the risk of recurrence in a subsequent pregnancy?
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This depends on the cause. Most cases are not hereditary. The exact risk for recurrence
is determined within genetic
counseling based on the cause of the edema, the pedigree, the results of
tests such as
chromosome analysis, etc.
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Molecular genetic information
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The gene for the disease
Depends on the cause/type
Its location
Depends on the cause/type
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Genetic testing
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Diagnostic testing
Depends on the cause/type
Carrier testing
Depends on the cause/type
Fetal testing
Depends on the cause/type
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