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Q: The impact of CMV in the first trimester of pregnancy ( Answered,   0 Comments )
Subject: The impact of CMV in the first trimester of pregnancy
Category: Health > Conditions and Diseases
Asked by: zidag-ga
List Price: $52.00
Posted: 29 May 2006 00:14 PDT
Expires: 28 Jun 2006 00:14 PDT
Question ID: 733253
I am currently 10 weeks pregnant and was diagnosed with CMV on May
2nd. It seems to be a primary infection (I do not seem to have had CMV
beforehand), but they are unsure as to whether it occurred right
before I got pregnant, or during the early stages of the first
trimester itself. Blood tests on May 24th showed my Avidity to be 21%,
my IGG to be 4.90 IU/ML and my IGM to be positive...Is there any way
to know definitively when I became infected? Does it even make a
difference? And what are the chances/percentages that the baby will be
affected by the CMV? And if it is infected, what are the chances of
possible birth defects, and what are those potential birth defects? We
can't seem to get a straight answer. Do most doctors suggest aborting
in these cases? We really hope not, but we don't know what to do.
Thank you so much for all your help. It really means a lot to us.
(Please also include any relevant referances.)
Subject: Re: The impact of CMV in the first trimester of pregnancy
Answered By: crabcakes-ga on 29 May 2006 11:43 PDT
Hello Zidag,

   First, congratulations on your pregnancy! Please also keep in mind
that this answer offers some grim statistics, and is for informational
purposes only, and not intended to diagnose, treat, or replace the
advice of a licensed physician. I urge you to consult with a
perinatologist and be tested further before making any decisions.

   While impossible to determine exactly when you were infected, your
avidity test, also called AI, indicates that you may have been
infected early in your pregnancy or shortly before. Studies indicate
that anywhere from 5% to  40% of babies born to infected mothers
suffer from hearing and vision loss, mental retardation, and other
maladies described in this answer. The reason CMV infection affects
fetuses is that CMV crosses the placental barrier and affects the
fetus directly.

   ?The recommended diagnostic threshold (DT) for exclusion of a
recent infection (within the past 3 months) was an avidity index (AI)
?80%. A comparative study of the performances of the Vidas method and
an in-house denaturation assay was described previously?

   ?IgG avidity measures how tightly antibody binds to antigen and
increases with time after initial infection; high avidity indicates
that infection occurred at least several months previously, although
avidity may remain low for many months. Interpretation depends on
individual test methods and should be discussed with a clinical
microbiologist, as should any other doubts about diagnosis.?

?Most congenitally infected infants are apparently normal at birth,
but long-term sequelae, most commonly deafness and mild intellectual
impairment, occur in up to 40% (10%?15% of all infants of women with
primary infection during pregnancy). Symptomatic multisystem disease,
characterised by growth retardation, microcephaly, intracranial
calcification, thrombocytopenia and hepatitis, is uncommon.?

?If recent CMV infection is likely or cannot be excluded, especially
in the first trimester, amniocentesis should be considered to
determine whether the fetus is infected. It should be done at about 19
weeks' gestation, or at least six weeks after the likely time of
infection. CMV isolation or positive nucleic acid test results from
amniotic fluid indicate fetal infection, but not necessarily
morbidity, while negative results indicate that severe fetal morbidity
is extremely unlikely. If fetal infection is confirmed, the stage of
pregnancy at which it occurred, viral load in the amniotic fluid and
evidence of fetal abnormality or growth retardation on ultrasound
examination may aid in considering termination of pregnancy.?

   ?Thus, low avidity in the in-house ELISA was defined as an AI of 
50%, whereas high avidity was defined as an AI of  60%.?

?Defined as the strength with which the IgG attaches to antigen, IgG
avidity matures with the length of time following primary infection.
Thus, IgG produced within the first 3 to 5 months following primary
infection exhibits low avidity, whereas IgG produced several months or
years later exhibits high avidity (3-5, 9-12). Detection of
low-avidity CMV IgG in a pregnant woman indicates that primary CMV
infection may have occurred since conception, and the fetus may be at
increased risk for congenital CMV.?

   ?Because CMV-specific IgM may be produced in low levels in
reactivated CMV infection, its presence is not always indicative of
primary infection. Only virus recovered from a target organ, such as
the lung, provides unequivocal evidence that the current illness is
caused by acquired CMV infection. If serologic tests detect a positive
or high titer of IgG, this result should not automatically be
interpreted to mean that active CMV infection is present. However, if
antibody tests of paired serum samples show a fourfold rise in IgG
antibody and a significant level of IgM antibody, meaning equal to at
least 30% of the IgG value, or virus is cultured from a urine or
throat specimen, the findings indicate that an active CMV infection is
Recently, IgG avidity assays, which measure antibody maturity, have
been shown in most cases to reliably identify primary CMV infection.
These assays may be used in conjunction with IgG and IgM assays, but
are not yet commercially available in the United States.?

   ?This study assessed the diagnostic value of the cytomegalovirus
(CMV)-specific IgG avidity index (AI) for pregnant women without a
history of CMV seroconversion. Sera were studied from 40 women with
CMV seroconversion (group I), 70 with past CMV infection (group II),
10 (20 sera) with serologic reactivation (group III), and 41 with
CMV-specific IgM without proven seroconversion (group IV). Sera from
women in group I collected <14 weeks after seroconversion had a low AI
(mean, 30% +/- 12%), whereas all sera from women in group II had an AI
>60% (mean, 88% +/- 9%). Among the 41 babies born to group IV women,
only 4 were infected with CMV (all born to mothers with a low [<30%]
AI early in pregnancy). These results suggest that AI determination
may help to date a primary CMV infection in pregnant women who lack
seroconversion history.?

   ?Defined as the strength with which the IgG attaches to antigen,
IgG avidity matures with the length of time following primary
infection. Thus, IgG produced within the first few months following
primary infection exhibits low avidity, whereas IgG produced several
months or years later exhibits high avidity. Several groups of
investigators have shown that detection of CMVspecific IgG of low
avidity is a reliable indicator of infection within the previous 6-8
months. However, detection of CMV-specific IgG of high avidity is
actually more informative from a clinical standpoint; the presence of
high avidity IgG essentially excludes the possibility that infection
occurred within the previous 4 months.?

   ?Diagnosis of primary CMV infection in immunocompetent adults is
accomplished by serological methods (3). CMV-specific immunoglobulin M
(IgM) is a sensitive indicator of an ongoing or recent infection.
However, it is not a specific indicator of primary infection, as it is
often produced during nonprimary infections (2, 10, 15). Another
serological procedure useful in identifying primary infections is the
determination of IgG avidity?

   ?CMV is a member of the herpes virus family and is ubiquitous in
the environment. It is associated with a mononucleosis-like illness
that may be indistinguishable from other viral illnesses.

Between 1-4% of non-immune pregnant women have a primary CMV infection
during pregnancy. Forty percent of the time, the infection is
transmitted to the fetus. The risk for congenital infection appears to
be highest when the maternal infection has occurred in the first half
of pregnancy. Of those fetuses that are infected, 10"-1"5% have
clinically apparent disease at birth, typically including
microcephaly, hepatosplenomegaly and chorioretinitis. The mortality in
symptomatic newborns is 20-30%. The 85-90% with inapparent disease
have a 5"-1"5% chance for long-term sequelae (most commonly hearing

   ?Congenital CMV often results in hepatosplenomegaly,
chorioretinitis, microcephaly, periventricular calcifications,
hydrocephaly, sensory neural hearing loss, mental retardation, and
intrauterine growth retardation. Ninety percent of affected newborns
are asymptomatic at birth, however, 5-17% of these babies may develop
symptoms within two years. Children that develop symptoms later are at
risk for sensorineural hearing loss, chorioretinitis, and neurologic
deficits (Grose et al., 1989). Of the 10% of infants affected at
birth, 90% have central nervous system (CNS) damage.

Primary infections result in an array of sequelae including
hepatosplenomegaly, chorioretinitis, microcephaly, hydrocephalus,
deafness, and mental retardation. Recurrent infections may be
associated with hearing loss (usually not bilateral), chorioretinitis,
and perhaps other neurologic sequela but do not appear to increase the
risk for mental retardation.?

?There exist differing opinions as to if there is a relationship
between the trimester in which the mother was infected and infant
outcome. Some researchers have found an association between infection
in the first half of pregnancy and more severe abnormalities, while
others have not found no such association.?

   ?CMV is the most common congenital viral infection in this country.
Each year in the United States, 30,000 to 40,000 infants are born
prenatally infected with the disease, meaning that the virus was
transmitted from mother to unborn baby.This constitutes approximately
1% of all babies born in this country. Of these infected newborns,
3,000 to 4,000 are symptomatic at birth and up to 10% of this group
die. An additional 4,500 to 6,000 babies with Congenital CMV, while
seemingly without health problems at birth, go on to develop
significant disabilities as they grow into early childhood.?

?Anyone seeking more information about CMV will soon discover the
puzzling contradictions of this insidious disease. Most Americans,
both male and female, have been infected with CMV by the time they
reach adulthood, with no ill effects. Some medical texts refer to CMV
as "the silent virus" because for the vast majority of those persons
who contract the illness, including those who are pregnant, there will
be no symptoms to alert the carrier that she has an active infection.?
The National CMV Registry may be able to send you further information.

The National CMV Registry 
Clinical Care Center, Suite 1150 
1102 Bates Street, MC 3-2371 
Houston, TX 77030 
Fax-(713) 770-4347

   ?An infected mother can transmit CMV to her unborn baby. The risk
to a baby is greatest if the mother has a primary infection,
particularly during early pregnancy. The risk is thought to be lower
if the mother has a reactivated infection.

Only about 10% of babies with congenital CMV have symptoms at birth.
These include small head size, enlarged liver and spleen and vision
and hearing loss. Many of these infants will have life-long
disabilities of varying degrees, including intellectual disability and
deafness. The majority of infants with congenital CMV do not have
symptoms at birth. However, about 10-15% of these children will
develop disabilities later in childhood, such as hearing loss,
learning difficulties and developmental delay.

?Cytomegalovirus (CMV) is a virus that can be transmitted to a
developing child before birth. CMV infection is usually harmless and
rarely causes illness. For most healthy persons who acquire CMV after
birth there are few symptoms and no long-term health consequences.
Once a person becomes infected, the virus remains alive, but usually
dormant within that person?s body for life. There are two differnet
types of infection: primary CMV and recurrent CMV infection. Primary
infection can cause more serious problems in pregnancy than recurrent
infection can.However, if a person's immune system is seriously
weakened in any way, the virus can become active and cause CMV
disease. For the majority of people who have CMV infection, it is not
a serious problem.?

?Transmission of CMV occurs from person to person and is not
associated with food, water, or animals. CMV is not highly contagious
but has been shown to spread in households and among young children in
day care centers. The infection is spread through close intimate
contact with a person excreting the virus in their saliva, urine,
breast milk or other bodily fluids.?

?If a pregnant women is diagnosed with the CMV infection, there are a
few ways that the fetus can be checked for infection. Amniocentises
can be done to check fetal fluids or blood for signs of infection.
Symptoms that could signify possible infection include low amniotic
fluid levels, Intrauterine growth restriction, and enlarged tissues in
the brain. Once the baby is born, testing can be done by saliva, urine
or blood.?

?Pregnant women who are infected with CMV rarely have symptoms, but
rather their developing baby may be at risk for congenital (meaning
from birth) CMV disease. CMV is the most common cause of congenital
viral infection in the United States. The transmission rate to the
fetus are between 24-75 % according to the Organization of Teratology
Information Service(OTIS), with an average transmission rate of 40%.
Of the 40 % of babies who become infected, only 10% show signs of
congenital CMV after primary maternal infection?

There are some statistics following this paragraph, but I did not pot
them here due to copyright restrictions. Please read the entire
informative site for compete information.

   ?Intrauterine transmission of cytomegalovirus (CMV) can occur
whether a mother has prior immunity or acquires CMV for the first time
during pregnancy. Most serious sequelae, however, have been noted only
after primary maternal infection.?

?approximately 5% to 25% of infected newborns develop cytomegalic
inclusion disease with intrauterine growth retardation, neonatal
jaundice, purpura, hepatosplenomegaly, microcephaly, brain damage,
intracerebral calcifications, and chorioretinitis. Acquired infections
at birth or shortly thereafter from mothers' milk or cervical
secretions are not associated with clinical neonatal illnesses.?

?Fortunately, congenital CMV infections in fetuses of women with
immunity acquired before pregnancy are less likely to be clinically
serious than those resulting from primary infection. Although the
presence of antibodies in the mother before conception does not
prevent transmission of CMV to her fetus, it helps prevent serious
harm because it protects the newborn against symptoms and against late
sequelae. The extent of this protection is not currently known.?

   ?The degree of protection afforded an infected infant by the
presence of antibody in the mother before conception is uncertain.?

?After a mean follow-up of 4.7 years, one or more sequelae were seen
in 25 percent of the primary-infection group and in 8 percent of the
recurrent-infection group. Thirteen percent of infants whose mothers
had primary infection during pregnancy had mental impairment (IQ less
than or equal to 70), as compared with none of those whose mothers had
recurrent CMV infections. Sensorineural hearing loss was found in 15
percent of those in the primary-infection group and in only 5 percent
of those in the recurrent-infection group. Bilateral hearing loss was
identified only among children in the primary-infection group (8
percent). CONCLUSIONS. The presence of maternal antibody to CMV before
conception provides substantial protection against damaging congenital
CMV infection in the newborn. Primary maternal infection during
pregnancy is associated with more severe sequelae of congenital CMV

   1.?Generalized infection may occur in the infant, and symptoms may
range from moderate enlargement of the liver and spleen (with
jaundice) to fatal illness. With supportive treatment most infants
with symptomatic CMV disease usually survive. However, from 80% to 90%
will have complications within the first few years of life that may
include hearing loss, vision impairment, and varying degrees of mental

2.Another 5% to 10% of infants who are infected but without symptoms
at birth will subsequently have varying degrees of hearing and mental
or coordination problems.

These risks are highest among women who previously have not been
infected with CMV and who are having their first infection with the
virus during pregnancy. Even in this case, two-thirds of the infants
will not become infected, and only10% to 15% of the remaining third
will have symptoms at the time of birth. There appears to be little
risk of CMV-related complications for women who have been infected at
least 6 months prior to conception. For this group, which makes up 50%
to 80% of the women of child-bearing age, the rate of newborn CMV
infection is approximately 1%, and significant illness or
abnormalities among these infants is infrequent.?

   ?Infants born to mothers who are infected early in pregnancy may be
more likely to be small for gestational age and to have microcephaly
and intracanial calcifications, whereas those infants who are born to
mothers infected later in pregnancy are more likely to have acute
visceral disease with hepatitis, pneumonia, purpura, and severe
thrombocytopenia. In populations in which the majority of women of
childbearing age have antibodies to CMV, there is a higher rate of
congenital CMV infection but not of clinical disease than in
populations with a lower prevalence of CMV antibodies. These
observations suggest that maternal antibody to CMV does not protect
the fetus from infection. This finding is in contrast to congenital
rubella and toxoplasmosis in which antibodies have been found to
protect the fetus against infection. Keep in mind that although
maternal antibodies do not appear to prevent transmission to the
fetus, they do prevent disease in the fetus, or alternatively, they
may be markers for another host factor that protects the fetus.
Primary infection with CMV during pregnancy is much more likely than
recurrent maternal infection to produce symptoms and sequelae in the

?It is calculated that 40,000 infants are born each year congenitally
infected with CMV; up to 10% of these will have symptoms at birth that
are commonly associated with congenital CMV disease, including
intrauterine growth retardation, jaundice, hepatosplenomegaly,
petechiae or purpura, thrombocytopenia, and pneumonia. Hepatomegaly,
splenomegaly and petechiae are the most common. The liver is usually
smooth and nontender and commonly measures 5cm or more below the RCM.
Ascites may be present prenatally and persist postnatally for 1-2
weeks. The hepatomegaly usually resolves by 3 months of age, and
persistence beyond 1 year is highly unusual. A mild hepatitis is
usually present, but the transaminase levels in neonatal hepatitis due
to CMV rarely exceeds 300 IU. Hyperbilirubinemia, on the other hand,
may be quite striking, with conjugated (direct) bilirubin levels up to
30 mg/dL. The abnormal results of liver function tests gradually
resolve over the first few weeks of life.?

   ?CMV is the most common congenital (present at birth) infection in
the United States. Each year about one percent of all newborns, or
about 40,000 babies, are infected. Fortunately, the majority of these
babies are not harmed by the virus. However, about 8,000 babies a year
develop lasting disabilities resulting from congenital CMV infection.?

?About 90 percent of babies who are infected with CMV have no symptoms
at birth. But as many as 15 percent of these babies develop one or
more neurological abnormalities ? such as mental retardation, learning
disabilities, hearing or vision loss ? usually in the first year or
two of life. Congenital CMV infection is a leading cause of hearing
loss in children.

About one in 1,000 babies (about 4,000 babies each year) shows
symptoms of CMV at birth. These symptoms may include an enlarged
spleen or liver, jaundice (yellowing of the skin and eyes), and a
distinctive rash. Up to 20 percent of these babies die, and about 90
percent of the survivors suffer from serious neurological defects,
such as mental retardation.

At present there is no treatment that can halt or reverse the effects
of congenital CMV. However, doctors are investigating whether a new
antiviral drug called ganciclovir ? which is used to treat adults with
AIDS who have CMV-related eye infections ? also may help babies with
congenital CMV.?

   ?Of the approximately 40% of fetuses that become infected, 10% of
neonates show symptoms of congenital CMV infections after primary
maternal infection at birth.  The brain, eyes, liver, spleen, blood,
and skin are at risk for problems. Long-term effects may include
sensorineural hearing loss, mental retardation, developmental delay,
and visual impairment. Of the remaining 90% with asymptomatic (no
evidence of disease at birth) congenital infection, 5-15% are at risk
to develop some of the long-term effects.  Discuss with your health
care provider whether you should see a specialist for further

   ?Nearly all women who have one baby with congenital CMV will be
protected from future CMV infections because they have developed
immunity. There have been few reports of mothers who gave birth to
more than one baby with congenital CMV. However, these cases are

 According to this page, amniotic fluid can be tested after 21 weeks gestation.

   To conclude, please discuss your concerns with your obstetrician.
S/he is most familiar with your results and your medical history. If
you don?t get answers from him/her, consider switching doctors. I'd
consider a consult with a perinatologist too, who is a specialist in
feto-maternal health.

Here?s a description of a perinatologist:
?In addition to basic obstetrics and gynecology training, the
perinatologist has completed a two-year or three-year clinical and
research fellowship. During this fellowship, he or she receives
advanced training in comprehensive diagnostic ultrasound imaging of
the fetus. These studies look for abnormalities in the head and neck
anatomy, spine, heart, chest and diaphragm, stomach, kidneys and
bladder, abdominal wall and umbilical cord, upper and lower
extremities, the placenta, and the volume of amniotic fluid. These
targeted ultrasounds are usually performed at about 18 to 20 weeks.
Further studies may be recommended later in the pregnancy if there are
problems that could affect the growth and development of the fetus,
such as problems with the volume of amniotic fluid?or the function of
the umbilical cord?that could affect blood flow.

Many perinatologists also develop diagnostic skills and can perform
complicated procedures when serious fetal disorders are suspected.
This may include sampling of the fluid surrounding the fetus
(amniocentesis), obtaining blood samples from the umbilical cord, or
placing catheters into the fetus.?
?Perhaps the most significant contribution of the perinatologist is as
a communicator. When given unsettling news about their baby, parents
need information from a knowledgeable and caring doctor who can
provide reassurance. The perinatologist can act as a sounding board
for parental concerns, provide options for care, and act as a liaison
between the referring doctor and the other members of the healthcare
team who become involved after birth. Careful collaboration among
perinatologists, neonatologists, and pediatric surgeons, or pediatric
cardiologists, improves the prospects of a healthy outcome for an
infant with special healthcare needs.

As advocates for both baby and mother, perinatologists are in a unique
position to maximize perinatal health outcomes.? 

  As far as abortion, this will have to be a decision made by yourself
and your doctors. It is a very difficult and personal decision;
hopefully made only after amniotic fluid testing. A fetal CMV
infection can, at times, itself induce a miscarriage. Should you
decide, along with advice of a perinatoogist, to continue your
pregnancy, you will likely be advised to deliver by Caesarian section,
and possibly be advised not to breastfeed.

?Pregnancy and CMV
Nov 27, 2001 
Last December my pregnancy test results came back showing that I have
CMV. My doctor recommended that I have an abortion. One year later
after another blood test they show my antibodies to still be very high
with CMV. How much longer will it take for my antibodies to go down.
Are there any medicines for curing CMV? I would like to get pregnant
again very soon. PLEASE HELP?

Dr Feinberg answers: ?If your test last year was a positive CMV IgM,
then your doctor was right to suggest an abortion. However, even if
you were CMV IgM+ last year, by now you should be CMV IgG+, and that
should not stop you from being pregnant. (If your test last year was a
positive IgG, and not a +IgM, then your doctor gave you bad advice'
and you might want to find another oBSTETRICIAN.) Good luck!?

   ?CMV: This is associated with random miscarriage but not recurrent
miscarriage. A large study conducted by Stagno et al observed 3712
pregnant patients and documented only 21 per 3712 cases of primary
maternal CMV infection during pregnancy. Only 11 of the 21 showed
neonatal infection, and SABs did not occur in this group.?

   ?In general there are three major mechanisms that an infectious
agent can affect pregnancy outcome: ascending infections,
transplacental infection and infections acquired through the birth
Ascending infections occur when microorganisms residing in the
external genitalia of the pregnant women gain access to the amniotic
sac. This event can debilitate the sac and eventually rupture it. The
infectious agent then will spread over the amniotic fluid. At this
point the fetus can become infected by aspirating the microorganisms
to the lungs, by swallowing them or by penetration to the ear canal.
Also the inflammatory reaction on the amniotic sac triggered by the
infection could initiate labor.
In cases of transplacental infection the mother must have the
infection along with presence of circulating microorganisms in blood.
Then they penetrate the placenta and affecting its well functioning
and could also invade the fetus.?

Further Information:

    I wish you all the best, and my hopes are for a healthy newborn
baby! If any part of my answer is unclear, please ask for an Answer
Clarification, and allow me to respond, before rating. I will be happy
to assist you further on this question, before you rate.

Sincerely, Crabcakes

Search Terms
fetal testing + CMV + primary infection
CMV + pregnancy
Avidity index IgG-CMV
cmv + fetus
incidence abortions + CMV
cmv  avidity  
cmv infection + early pregnancy + risks
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