MOTHER-TO-CHILD DISEASES
MOTHER-TO-CHILD DISEASES
CYTOMEGALOVIRUS (CMV)
GENERAL OVERVIEW OF MOTHER-TO-CHILD DISEASES
The mother-to-child disease is an umbrella-term to refer to several infectious diseases that can be
transmitted from the mother to her child. The transmission may occur in the placenta (congenital, or
in-utero infection), during parturition (perinatal
infection), or during the first days of child life
(newborn infection).
There are different pathogens that may cause
mother-to-child diseases, and the most
common types are three, which are:
• Viruses: they are CMV, parvovirus B19,
rubella virus, measles, HSV-1, HSV-2,
VZV, coxsackie B virus, and mumps.
• Bacteria: they are group B Streptococci
(S. agalactiae), L. monocytogenes, E. coli, Gardnerella vaginalis, C. trachomatis, Treponema
pallidum, and Ureaplasma urealyticum.
• Parasites: they are Toxoplasma gondii, Trypanosoma cruzi (Chagas disease), and Malaria spp.
For some infections during pregnancy, the mother is minimally, if at all, affected, but transmission to
the foetus is a major concern, and the consequences of foetal infection can be devastating. In many
infections, growth of the foetus may be affected
(intrauterine growth retardation) or the infant
may be delivered prematurely (miscarriage,
preterm birth), even in the absence of congenital
infection. Note that the risk of foetal infection is
higher in case of primary infections compared to
reactivation of previous infection or infection from
other variants. Therefore, it is important to
determine whether the maternal infection is
recent, previous, or related to reactivation.
In the later years it was observed an increased in these infections, even in the ones that can be
prevented via vaccination (e. g. VZV).
VIRUS AND TRANSMISSION
The cytomegalovirus (CMV), or human herpesvirus 5 (HHV-5) is the most common congenital viral
infection in the world, with a prevalence rate among all live births of approximately 0.5%-2%. It is the
leading cause of permanent
sequelae, responsible for 25% of
cases of congenital sensorineural
hearing loss, 10% of cases of cerebral
palsy, and severe other neurological
manifestations. As the other
herpesviruses, it is associated with
infections that have a persistent and
latent pattern.
The primary infection is associated
with or without any clinical manifestations, while CMV reinfection is caused by other viral strains. The
viral reactivation is observed when the patient’s immune status is compromised (e. g. pregnancy).
The CMV contamination occurs through direct contact of the mucous membrane with contaminated
body fluids, such as urine, saliva, blood, genital secretions, tears, contaminated breast milk, solid
, organ transplants, and stem cells. The major risk for maternal infection is contact with children
younger than 2 years, who can shed the virus in saliva and urine for more than 24 months. Another
significant route is the sexual transmission.
Note that the congenital infections are more severe compared to neonatal infections. A way to
differentiate them is to search for CMV in the urine within a week from parturition. However, the
major risk of contamination occurs during the first 2 years.
SYMPTOMS
The infection acquired during pregnancy is asymptomatic in about 90% of women, while it may cause
a mononucleosis-like symptoms (e. g. mild illness, fever, rhinitis, myalgia, fatigue). The main difference
compared to EBV infection is that there is a heterophile-
negative profile. Abnormal liver function tests (elevated
liver enzymes), atypical lymphocytosis, haemolytic
anaemia, and thrombocytopenia may be developed. Other
symptoms include pneumonia, encephalitis, neuropathy,
hepatitis, digestive, and urinary tract diseases.
Similarly to pregnant women, 80%-90% of children develop
an asymptomatic infection. The risk pf vertical transmission
of CMV in utero increases with advancing gestation, but the
risk of foetal complications is directly proportional to the
trimester. The main symptoms are:
• Congenital hearing loss.
• Mental retardation.
• Congenital inclusion disease.
• Long-term sequelae.
TESTS
The main recommendations for CMV are hygienic measures since no efficient treatments are present.
Examples are handwashing in case of contact with children’s saliva or urine or avoiding intimate
contact, such as kissing and sharing utensils.
The diagnosis for CMV is based on serological
testes. However, IgM alone cannot be used since
they may present cross-reactivity with EBV, VZV,
and autoimmune disease; moreover, they are
long-lasting. Therefore, they cannot be used to
determine a primary infection. Conversely, the
IgG avidity should be checked. Different scenarios
can be present, which are:
• No infection: there is nonreactive IgG,
IgM, and IgG avidity.
• Past infection: there is reactive IgG,
nonreactive IgM, and high avidity IgG;
there is low risk of in-utero transmission.
• Primary infection: there is reactive IgG,
reactive IgM, and low avidity IgG; there
is a high-risk of in-utero transmission.
• Ongoing infection: there is reactive IgG,
reactive IgM, and high avidity IgG; there
is a low-risk for in-utero transmission.
Therefore, based on the serology it is possible to evaluate the type of infection that is present and the
risk of congenital infection. The problems are that about 30% of women present IgG in the grey zone.
MOTHER-TO-CHILD DISEASES
CYTOMEGALOVIRUS (CMV)
GENERAL OVERVIEW OF MOTHER-TO-CHILD DISEASES
The mother-to-child disease is an umbrella-term to refer to several infectious diseases that can be
transmitted from the mother to her child. The transmission may occur in the placenta (congenital, or
in-utero infection), during parturition (perinatal
infection), or during the first days of child life
(newborn infection).
There are different pathogens that may cause
mother-to-child diseases, and the most
common types are three, which are:
• Viruses: they are CMV, parvovirus B19,
rubella virus, measles, HSV-1, HSV-2,
VZV, coxsackie B virus, and mumps.
• Bacteria: they are group B Streptococci
(S. agalactiae), L. monocytogenes, E. coli, Gardnerella vaginalis, C. trachomatis, Treponema
pallidum, and Ureaplasma urealyticum.
• Parasites: they are Toxoplasma gondii, Trypanosoma cruzi (Chagas disease), and Malaria spp.
For some infections during pregnancy, the mother is minimally, if at all, affected, but transmission to
the foetus is a major concern, and the consequences of foetal infection can be devastating. In many
infections, growth of the foetus may be affected
(intrauterine growth retardation) or the infant
may be delivered prematurely (miscarriage,
preterm birth), even in the absence of congenital
infection. Note that the risk of foetal infection is
higher in case of primary infections compared to
reactivation of previous infection or infection from
other variants. Therefore, it is important to
determine whether the maternal infection is
recent, previous, or related to reactivation.
In the later years it was observed an increased in these infections, even in the ones that can be
prevented via vaccination (e. g. VZV).
VIRUS AND TRANSMISSION
The cytomegalovirus (CMV), or human herpesvirus 5 (HHV-5) is the most common congenital viral
infection in the world, with a prevalence rate among all live births of approximately 0.5%-2%. It is the
leading cause of permanent
sequelae, responsible for 25% of
cases of congenital sensorineural
hearing loss, 10% of cases of cerebral
palsy, and severe other neurological
manifestations. As the other
herpesviruses, it is associated with
infections that have a persistent and
latent pattern.
The primary infection is associated
with or without any clinical manifestations, while CMV reinfection is caused by other viral strains. The
viral reactivation is observed when the patient’s immune status is compromised (e. g. pregnancy).
The CMV contamination occurs through direct contact of the mucous membrane with contaminated
body fluids, such as urine, saliva, blood, genital secretions, tears, contaminated breast milk, solid
, organ transplants, and stem cells. The major risk for maternal infection is contact with children
younger than 2 years, who can shed the virus in saliva and urine for more than 24 months. Another
significant route is the sexual transmission.
Note that the congenital infections are more severe compared to neonatal infections. A way to
differentiate them is to search for CMV in the urine within a week from parturition. However, the
major risk of contamination occurs during the first 2 years.
SYMPTOMS
The infection acquired during pregnancy is asymptomatic in about 90% of women, while it may cause
a mononucleosis-like symptoms (e. g. mild illness, fever, rhinitis, myalgia, fatigue). The main difference
compared to EBV infection is that there is a heterophile-
negative profile. Abnormal liver function tests (elevated
liver enzymes), atypical lymphocytosis, haemolytic
anaemia, and thrombocytopenia may be developed. Other
symptoms include pneumonia, encephalitis, neuropathy,
hepatitis, digestive, and urinary tract diseases.
Similarly to pregnant women, 80%-90% of children develop
an asymptomatic infection. The risk pf vertical transmission
of CMV in utero increases with advancing gestation, but the
risk of foetal complications is directly proportional to the
trimester. The main symptoms are:
• Congenital hearing loss.
• Mental retardation.
• Congenital inclusion disease.
• Long-term sequelae.
TESTS
The main recommendations for CMV are hygienic measures since no efficient treatments are present.
Examples are handwashing in case of contact with children’s saliva or urine or avoiding intimate
contact, such as kissing and sharing utensils.
The diagnosis for CMV is based on serological
testes. However, IgM alone cannot be used since
they may present cross-reactivity with EBV, VZV,
and autoimmune disease; moreover, they are
long-lasting. Therefore, they cannot be used to
determine a primary infection. Conversely, the
IgG avidity should be checked. Different scenarios
can be present, which are:
• No infection: there is nonreactive IgG,
IgM, and IgG avidity.
• Past infection: there is reactive IgG,
nonreactive IgM, and high avidity IgG;
there is low risk of in-utero transmission.
• Primary infection: there is reactive IgG,
reactive IgM, and low avidity IgG; there
is a high-risk of in-utero transmission.
• Ongoing infection: there is reactive IgG,
reactive IgM, and high avidity IgG; there
is a low-risk for in-utero transmission.
Therefore, based on the serology it is possible to evaluate the type of infection that is present and the
risk of congenital infection. The problems are that about 30% of women present IgG in the grey zone.
