ultrasound diagnosis of fatal anomalies

INFECTIONS
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Toxoplasmosis
Definition: This is a parasite infection with Toxoplasma
gondii. Maternal infection follows consumption
of raw meat, raw milk products, or
contamination through cat excrement. There is
transplacental infection of the fetus, most severe
during the first and second trimesters. Most congenital
infections result after transmission in the
third trimester.
Incidence: One in 100–1000 pregnancies. Fetal
transmission occurs in 40% if it is a primary infection
of the mother during the pregnancy.
Seventy-five percent of these fetuses show no
symptoms, whereas 10% are severely affected.
Origin: Fetal cells are destroyed by this infection.
Clinical features: Chorioretinitis, hydrocephalus,
cataract, thrombocytopenia, anemia, and hydrops.
Ultrasound findings: Intracranial calcifications
are a typical feature, and are distributed randomly
(in contrast to cytomegalovirus infection).
Hepatosplenomegaly with echogenic structures
within the liver is detected. Dilation of cerebral
ventricles, the posterior horns of the lateral
ventricles are the first to be affected. Ascites,
pleural effusion, and full-fledged hydrops may
result. Following this, hydramnios, placentomegaly
with echogenic structures and growth
restriction are frequent findings.
Differential diagnosis: Cytomegalovirus infection.
Clinical management: Toxoplasmosis serology
from maternal and fetal blood samples: the fetal
IgM is first detectable after 20 weeks of gestation.
Amniotic fluid PCR. Antibiotics should be
given to the mother.
Procedure after birth: Blood and other secretions
of the newborn may be infectious. Moderate
jaundice, anemia, and hepatosplenomegaly
are often present. The infant should be
treated with antibiotics for a period of 1 year.
Prognosis: Most congenital toxoplasmosis infections
do not show any clinical symptoms. In
severe cases, the mortality may be as high as
12%. The central nervous system and eyes are affected
in about 80% of infants, with severe infection
causing mental impairment, fits, cerebral
palsy, hydrocephalus and sensorineural hearing
loss. Infections at an early stage of gestation affect
the fetus most severely and often result in
intrauterine fetal demise or severe central
nervous system anomalies. Even in asymptomatic
children, chorioretinitis and neurological
injury may develop during the later course (up
to the age of 10).
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