Book of Medical Disorders in Pregnancy - Tintash

identifying a primary infection
accurately.
Immunity: Infection with CMV confers
immunity in the host because persistence
of the agent in a latent phase and
reactivation in response to various
stimuli occurs. Although unusual, a
woman may bear a second child with
congenital infection of the same serotype.
Since cytomegalovirus exists in
multiple serotypes, reinfection of a
woman in the childbearing age with a
different type can result, in the birth of
another infected infant to the same
mother. These occurrences nevertheless
are very rare. In general after the birth of
a congenitally infected infant the fetus in
the subsequent pregnancy is not at
significantly greater risk.
Fetal infection: Intrauterine infection
with CMV is probably the most common
viral infection of the human fetus. It has
been estimated that the prevalence of
CMV infection at birth shows a
frequency of 4 to 10 infected infants per
1,000 births. Many points of similarity
can be found between congenital CMV
and Rubella, but in general there is a
lower frequency of congenital disease in
CMV with a preponderance of damage
to the CNS in contrast to the
combination of malfor-mation and
congenital disease which is to be found
in infants with congenital Rubella.
Another common feature is that the
infant may be excreting virus at birth yet
show no symptoms. The majority remain
unaffected as they grow older.
Approximately one in 10 of congenitally
infected infant develops symptoms. The
fulminating illness may present with
hepatosplenomegaly, jaundice, petechial
rash and low birthweight. The infant
may also be premature. The mortality
168
rate is high, particularly if CNS
involvement is prominent or respiratory
distress is present. The prognosis for
infants with jaundice and thrombocytopenic
purpura alone is better than for
those who have CNS involvement. In
many infants with the former symptoms
recovery is complete in 6 to 8 weeks, but
there is always the possibility that other
symptoms may develop later. The
neurological symptoms are of the
greatest consequence both in the short
terms and long terms. Microcephaly may
be obvious at birth or become apparent
later in infancy. Cerebral diplegia,
spasticity and fits presenting early in life
usually have a bad prognosis. Henshaw
et al (1973) found a higher incidence of
CMV infection determined by the presence
of CF antibody in children with
undiagnosed seizures and microcephaly
than in patients with genetically determined
CNS disease and in a control
group of normal children.
Fig13.3: shows CMV infection rash on
the body
Toxoplasmosis: Toxoplasma gondii is a
parasite which has a proliferative
(invasive) phase and a cystic (resistant)
phase. The resistant phase is formed in
response to the immune reaction of the
host. The mode of infection is unknown.
The infection occurs in most parts of the
world but is particularly prevalent in
warm and humid climates.