Download Congenital blood disorders - Congenital Anomaly Register and

ANNUAL REPORT 2016
The annual report of CARIS in 2016 gave headline information on most of the congenital
anomalies recorded on CARIS, but had a specific focus on congenital blood disorders and
also on congenital infections.
CONGENITAL BLOOD DISORDERS
There are a large number of congenital blood disorders, some more common than others.
Blood disorders seen in cases recorded on the CARIS database include :

Sickle cell disease

Thalassaemia

Haemophilia A

Haemophilia B

Von Willebrand disease

G6PD deficiency

Hereditary spherocytosis and elliptocytosis

Aplastic anaemias
There are other congenital disorders which affect the blood and although relatively
common, do not often appear as cases on the database. This is because they do not appear
until adulthood or late childhood, and so are often not reported into CARIS. An examples of
this is haemochromatosis .
Blood cells start to develop during the third week of pregnancy but blood formation starts
properly during the fifth week in the liver, and later during pregnancy in the spleen, bone
marrow and lymph nodes. Three kind of blood cells form about 45% of the blood tissue,
these are red blood cells (erythrocytes), white blood cells (leukocytes) and platelets
(thrombocytes). Blood disorders include conditions that affect both red and white blood
cells, platelets, bone marrow, and the blood constituents involved in clotting or bleeding.
SICKLE CELL DISEASE
What is it?
Sickle cell disease (SCD) is a group of inherited blood disorders, which occur when abnormal
haemoglobin occurs in the red blood cells. The most common type of SCD is sickle-cell
anaemia. Red blood cells that contain normal haemoglobin are disc shaped. This shape
allows the cells to be flexible so that they can move through large and small blood vessels to
deliver oxygen. In sickle cell disease, the haemoglobin forms stiff rods within the red cell,
changing it into a crescent, or sickle shape. These cells are not flexible and can stick to vessel
walls, causing a blockage that slows or stops the flow of blood and as a result oxygen. This
can cause a sickle crisis with severe pain. It can also cause infection and organ damage.
Normal red blood cells live about 90 to 120 days, but sickle cells last only 10 to 20 days. As a
result anaemia is common. Exacerbation of sickle cell disease can be caused by dehydration,
infections, stress, extremes of temperature or even changes in altitude.
What are the genetics, is it hereditary?
Yes - babies born with sickle cell disorder inherit two abnormal haemoglobin genes, one
from each parent. When a person has two haemoglobin S (HbS) genes, the disease is called
sickle cell anaemia. Where a person has only one HbS gene alongside a ‘normal’
haemoglobin gene (HbA) they are said to have sickle cell trait (HbAS) and their health is not
adversely affected by this. However there is a one in four chance that should they have a
child with another person who also has sickle cell trait the baby will be born with sickle cell
anaemia (HbSS). For more information on inheritance, the Sickle Cell society website
http://sicklecellsociety.org/ contains useful information.
How is it detected?
In the antenatal period women are offered screening for sickle cell disorder if their
responses to a questionnaire indicate they may be at higher risk of sickle cell disorder.
Those at higher risk include women whose country of origin or ancestry includes Africa,
Caribbean, Mediterranean, India, Asia and the Middle East. If a woman is found to be a
carrier then the father of the baby is screened. If he too is a carrier then the woman is
offered testing to determine the status of the baby. This could be either chorion villus
sampling or amniocentesis. For more information see the antenatal screening website
www.antenatalscreening.wales.nhs.uk/
All newborn babies in Wales are tested for sickle cell disease as part of the newborn
bloodspot screening. A small sample of blood is taken from the baby’s heel, ideally on day
five of the baby’s life, and tested for a number of conditions including sickle cell disease.
More information can be found on the newborn bloodspot screening website
http://www.newbornbloodspotscreening.wales.nhs.uk/home
What is the outlook?
Early identification with antenatal screening or newborn bloodspot screening means that
affected babies can receive early preventive treatment including immunisations and
antibiotics to mitigate against serious illness. Sickle cell disease is a life long illness with life
expectancy greatly improved over the last 30-40 years with careful management.
How common is sickle cell disease in Wales?
The Public Health Wales screening division suggest a UK prevalence of sickle cell disease as
1/2,000 live births, however there is much lower prevalence in Wales than in some other
parts of the UK. There is greater prevalence of sickle cell disease where communities are
more ethnically diverse, so it is seen more often in towns and cities than in rural areas. 27
cases of sickle cell disease are recorded on the CARIS database, an average rate of
0.4/10,000 total births.
There are obviously more carriers of the disease than people with the disease, and
Orphanet estimates that prevalence of carriers across Europe as 1/150.
More information
http://www.nhsdirect.wales.nhs.uk/encyclopaedia/s/article/sicklecellanaemia/
THALASSAEMIA
What is it?
Thalassaemia is the name for a group of conditions which, like sickle cell disease, affects
haemoglobin. In these conditions, too little or no haemoglobin is produced by the body.
The condition can lead to people having too much iron in their bodies, and they may also be
anaemic and more prone to infections.
Thalassaemia is caused by a defect in the protein chains that make haemoglobin. There are
two alpha and two beta chains. Thalassaemia is classified according to which chain of the
hemoglobin molecule is affected. In alpha-thalassaemia (α-thalassaemia) production of the
α globin chain is affected, while in beta-thalassaemia (β-thalassaemia) production of the β
globin chain is affected. The most severe type of thalassaemia is beta thalassaemia major,
and people with this condition cannot produce normal red blood cells and do not produce
enough haemoglobin. Other types include haemoglobin H disease.
The beta globin chains are encoded by a single gene on chromosome 11 and alpha globin
chains are encoded by two closely linked genes on chromosome 16. Thalassaemia is most
common among people of Mediterranean, south Asian, or Middle Eastern descent, with
males and females having very similar rates of disease. It is also possible to be a carrier of
the condition (thalassaemia trait).
Is it inherited?
Yes, like sickle cell disease it is an autosomal recessive gene resulting in varying degrees of
severity depending on the parents contribution.
How is it detected?
Antenatal screening Wales offers all pregnant women screening for thalassaemia. If the
mother is found to be a carrier then this can be passed on to the baby but only as a carrier.
If both parents are carriers then the inheritance is similar to sickle cell disorder with a 1 in 4
chance of the baby being born with thalassaemia. It is not screened for at birth with the
newborn bloodspot screen.
What is the outcome?
Children born with thalassaemia usually develop symptoms a few months after birth,
however less severe types of thalassaemia may not become obvious until later on in
childhood. Carriers have no symptoms.
Anaemia is a significant problem for people with the condition and regular blood
transfusions are needed by those affected . Lifelong treatment to stop iron building up to
harmful levels after multiple blood transfusions is usually needed. This is known as chelation
therapy. The overload of iron in the body can cause complications for major organs, bones
and hormones, which are associated with possible heart failure, osteoporosis and delayed
or incomplete puberty.
These complications are also associated with an increased risk to both mother and baby
during pregnancy, with a higher risk of maternal cardiomyopathy and diabetes as well as
fetal growth restriction. Most women with thalassaemia will also require ovulation
induction therapy to achieve pregnancy.
How common is thalassaemia in Wales?
Thalassaemia is rare in Wales, and on average, only one case per year is reported to the
CARIS database. A total of 25 cases have been reported to the database in Wales between
1998 and 2015, giving a rate of 0.4/10,000 births. Worldwide, exact prevalence is unknown.
However Orphanet, the online portal for rare diseases gives estimated prevalence
worldwide of beta-thalassaemia as 1/100,000, and estimated prevalence of alphathalassaemia in northern Europe as the same.
More information
https://www.rcog.org.uk/en/guidelines-research-services/guidelines/gtg66/
http://www.nhsdirect.wales.nhs.uk/encyclopaedia/t/article/thalassaemia/
HEREDITARY SPHEROCYTOSIS
What is it?
Hereditary spherocytosis (HS) is an inherited condition affecting red blood cells, and the
condition can be mild, moderate, or severe. In HS, red blood cells change shape to become
more sphere-shaped (spherocytic red blood cells) as the surface membrane is less stable.
The change in shape makes it more difficult for the red blood cells to travel around the
body, and more prone to rupture. Spherocytic red blood cells are easily destroyed and may
last for only a few days, compared to 120 days for normal red blood cells. The destruction of
the abnormal red blood cells takes place in the spleen. This abnormal breakdown of red
blood cells can lead to a form of anemia called haemolytic anaemia. This can in turn lead to
jaundice because of an increase in circulating bilirubin produced during haemolysis.
What are the genetics?
Hereditary spherocytosis is an autosomal dominant or recessive trait, most commonly
(though not exclusively) found in people of northern European descent, although an
estimated 25% of cases are due to spontaneous mutations. A parent has a 50% chance of
passing the mutation onto each of his/her offspring.
How is it detected?
Antenatal screening for HS is not part of the antenatal screening programme in Wales but
there is potential for an antenatal diagnosis using cordocentesis and examining the
morphology of the fetal blood cells. Severe anaemia can present antenatally as hydrops1
which is easily identifiable with ultrasound.
Neither is screening for HS part of the newborn bloodspot screening. But severe HS can
present as jaundice in the neonatal period, occasionally requiring exchange transfusion, and
in these instances should be possible to diagnose while a baby is still very young.
1
Fetal hydrops is a serious condition for the fetus or newborn baby, in which abnormal amounts of fluid build
up in areas of the body such as the skin, abdomen, pericardium or pleura.
What’s the outcome?
Most children born with HS have a mild form of the disease, which does not interfere with
their lifestyle. However children born with severe hereditary spherocytosis (about 5% of HS
cases) are constantly anaemic, and may be transfusion dependent, especially in early life.
They may benefit from erythropoietin treatment, and this might reduce the need for
transfusions in the first year of life. After the first few years regular transfusion is rarely
needed as most children can tolerate a low haemoglobin level.
Haemolysis is associated with an increased risk of gallstones. Splenectomy may be
necessary because of the increased turnover of red cells and accompanying this, there is a
higher risk of contracting infections so it is important for children to have all the
recommended vaccines in line with national guidance on immunisation.
How common is hereditary spherocytosis Wales?
Orphanet suggests that prevalence in northern Europe could be as high as 1 / 2,000 but this
includes extremely mild and sub-clinical forms of the disease. 68 cases were registered on
the CARIS database by the end of 2015, giving a rate in Wales of 1.1/10,000 births.
More information
http://patient.info/doctor/hereditary-spherocytosis-pro
HAEMOPHILIA
What is it?
Haemophilia is an inherited condition that affects the blood’s ability to clot. There are two
main types, haemophilia A and haemophilia B. Haemophilia A is due to a deficiency in
clotting factor VIII and is the most common type of haemophilia. Haemophilia B is due to a
deficiency in factor IX. A third type – haemophilia C is due to a deficiency in factor XI, and is
a more rare and milder form and unlike the other forms of the disease, is not characterised
by spontaneous bleeding and does not lead to bleeding in the joints. In both haemophilia A
and B, the deficiency causes a prolonged bleeding time even after minor injury.
What are the genetics?
These are X-linked recessive disorders and so are more likely to occur in males than females.
This is because females have two X chromosomes while males have only one, so the
defective gene is guaranteed to manifest in any male who carries it. Because females have
two X chromosomes and haemophilia is rare, the chance of a female having two defective
copies of the gene is very remote, so females are almost exclusively asymptomatic carriers
of the disorder.
Congenital haemophilia affects all ethnic groups, and has a worldwide distribution, although
haemophilia C is found predominantly in people of Jewish Ashkenazi decent.
Detection
No antenatal or postnatal screening tests exist.
What’s the outcome?
Children with mild to moderate haemophilia may not have any signs or symptoms at birth.
Their first symptoms are often multiple and large bruises from frequent bumps and falls as
they learn to walk. Although there is no cure for haemophilia, it can be controlled with
regular infusions of the deficient clotting factor, i.e. factor VIII in haemophilia A or factor IX
in haemophilia B. Factor replacement can be either isolated from human blood serum,
recombinant or a combination of the two. Gene therapy offers a possible treatment and
trials have been encouraging.
Since effective treatments became available, life expectancy has increased significantly.
How common is haemophilia in Wales?
It is estimated that in boys, internationally, 1/5,000 will be born with haemophilia A, and
1/30,000 will be born with haemophilia B. There is a small risk that girls can be born with
the condition if both parents carry the gene. Between 1998 and 2015 there were 39 cases of
haemophilia A recorded on the CARIS database, and 5 cases of haemophilia B, so slightly
fewer than might be expected. This could be because not all cases are reported to the CARIS
database.
More information
http://www.nhsdirect.wales.nhs.uk/encyclopaedia/h/article/haemophilia/
http://www.haemophilia.org.uk/
VON WILLEBRAND DISEASE
What is it?
Von Willebrand disease is the most common hereditary blood clotting disorder and 3 types
of the disease have been identified, with type 3 being the most severe. It is caused by either
a deficiency in Von Willebrand factor, which is a blood protein, or the protein does not work
properly. Von Willebrand factor is required for platelet adhesion, and is named after the
Finnish physician who first described the disease in 1926. Von Willebrand Factor also carries
and protects another clotting factor - Factor VIII.
Von Willebrand disease can cause bruising with minimum trauma, nosebleeds and bleeding
gums. Women with the condition may have heavy periods and experience increased blood
loss during childbirth.
What are the genetics?
The gene involved is located on chromosome 12. There are 3 types with type 1 and 2 being
inherited as dominant and type 3 (the more severe) as recessive.
Management and outcome
Desmopressin is used to stimulate von Willebrand factor and is used for minor trauma or to
prepare for dental procedures. It is not used in certain types of the disease. Tranexamic acid
is also useful to reduce bleeding. If surgery is scheduled, certain factor V111 concentrates
which contain von Willebrand factors may be used as a precaution.
Detection
Routine screening for Von Willebrand disease is not part of the antenatal or neonatal
screening programme. It may only be diagnosed in women when they start menstruating
and have investigations for heavy periods.
How common is Von Willebrand disease in Wales?
The prevalence is internationally is thought to be about 1 in 100 but many people do not
have any symptoms and are never diagnosed with the condition. Prevalence of the most
severe form, type 3, is much lower, and has been estimated in various studies as between 1
to 3 per million population, although higher in populations where consanguineous
marriages are more common. People with blood type O have levels of Von Willebrand factor
about 25% lower than the rest of the population. About 80% of all cases are type 1. While
it occurs with equal frequency in males and females, women may be diagnosed more often
as they may present with heavy / painful periods or excess bleeding during childbirth.
Only 34 cases were recorded on the CARIS database between 1998 – 2015, far fewer than
expected, which suggests not only under-reporting of the condition to CARIS, but also many,
many cases go undiagnosed. Additionally there are UK guidelines recommending that
children should not be routinely tested for the disease before the age of 6 months, because
there are natural changes in the presence of Von Willebrand Factor in the blood in the early
months of life.
More information
http://www.nhsdirect.wales.nhs.uk/encyclopaedia/v/article/vonwillebranddisease/
http://www.haemophilia.org.uk/
CONGENITAL INFECTIONS
Congenital infections were one of the two areas of congenital anomaly that were the focus
of the 2016 report. The decision to focus on this area pre-dated the publicity generated by
Zika virus and associated microcephaly in south America. No cases of Zika-associated
microcephaly have yet been notified to the CARIS database, however enhanced surveillance
has been commenced in maternity units across the UK. For more information on the
surveillance please see the UKOSS website here https://www.npeu.ox.ac.uk/ukoss
For more information on Zika virus please see the NHS Wales health website here
http://www.nhsdirect.wales.nhs.uk/encyclopaedia/z/article/zikavirus/
133 cases of congenital infection were recorded on the CARIS database between 1998 and
2015. The infections that could have been reported include congenital syphilis, congenital
viral diseases including rubella, herpes, varicella (chickenpox) and cytomegalovirus, and
toxoplasmosis. However not all the infections listed were found on the database, for
example there were no cases of congenital rubella recorded. In 2016 Public Health Wales
updated the guidance on “Rash in Pregnancy” which can be found here :
http://www.antenatalscreening.wales.nhs.uk/sitesplus/documents/989/V2aFinal%20Infections%20in%20Pregnancy%202016.pdf
Historically CARIS has recorded all cases of congenital infection reported to the database
team, whether or not a congenital anomaly was detected at birth. This has resulted in a
number of records being held, where it is not clear that any anomaly exists. There are plans
to review the CARIS data definitions in 2016/17 and this is one of the areas that will be
reviewed.
CYTOMEGALOVIRUS (CMV)
What is it?
This is a relatively common virus that belongs to the herpes family of viruses. It is spread
through bodily fluids such as blood, saliva, semen, urine and vaginal fluids. The virus can
present as a ‘flu like illness or there may be no symptoms at all. The virus also has the
characteristic of being able to remain in the body without detection over long periods of
time, and in healthy people may go unnoticed. If a pregnant woman has either a new
infection or reactivation of an existing infection, the virus can pass to the developing baby.
How is it detected?
If the mother has an active infection, this can be picked up with a blood test for
immunoglobulins. The effects on the fetus can be detected on ultrasound scan if the effects
are significant, and the presence of CMV can be confirmed by testing amniotic fluid
following amniocentesis. The virus can be detected in urine and saliva in the newborn baby.
What are the effects on the fetus?
If a mother becomes infected for the first time in the first half of pregnancy the risk of
transplacental infection is about 40%. Of these babies, between 5 and 15% are affected at
birth. Effects may include hepatosplenomegaly, thrombocytopaenia, intracranial
calcifications, intrauterine growth restriction, jaundice, microcephaly, chorioretinitis,
hearing loss, learning difficulties and fits. Of those affected, up to 30% may die, while 80% of
the survivors will have ongoing serious health problems.
If the maternal CMV infection occurs later in pregnancy there is a much higher risk of
transplacental transmission but the risk to the baby is much less. One of the common
anomalies associated with CMV infection is sensorineural hearing loss and for this reason
many of the cases reported to CARIS are detected by the newborn hearing screening
programme. Later problems can present in children as neurologic, auditory, visual and
dental defects. If the mother has a recurrent or reactivated infection, there is a significantly
reduced risk of fetal problems.
How common is cytomegalovirus in Wales?
It is estimated that between one and two babies in every 200 will be born with congenital
CMV. Of these about 13% will have congenital anomalies relating to the infection. 54 cases
were reported to CARIS between 1998 and 2015. 78% of these were known to have a
congenital anomaly, predominantly sensorineural hearing loss. Given what is known about
international prevalence, the figure of 54 is probably under reported, as we could expect
more than 300 affected cases with anomalies since 1998. Many of the children will be mildly
affected with minor visual or auditory problems which may only become apparent when
they are in school and this could be a reason why they are never reported to CARIS.
More information
http://www.nhsdirect.wales.nhs.uk/encyclopaedia/c/article/cytomegalovirus/
www.perinatology.com/exposures/Infection/CMV/Cytomegalovirus.htm
TOXOPLASMOSIS
What is it?
This is a disease caused by the parasite Toxoplasma gondii. The parasite is found in cat
faeces and in infected meat and has to be ingested to cause infection, it cannot be spread
through person-to-person transmission. It can live in soil or water for a long time, so can be
spread to people in contact with infected soil i.e. through gardening. It can also be spread
from mother to fetus during pregnancy.
Infections in humans usually cause no symptoms, or simply a mild flu like illness. However
the infection can be more serious in people who are immunocompromised such as those on
long-term steroids or the very young, and acute toxoplasmosis in pregnant women can have
serious consequences for the fetus.
What are the effects on the fetus and baby?
It is thought that acute toxoplasmosis in the mother can result in a 30% chance of placental
and fetal infection. The chance of fetal infection increases with gestational age. The
outcomes can be serious and include fetal death and miscarriage. The baby may have
neurological problems, learning difficulties and chorioretinitis of the eyes. Treatment of the
mother with antibiotics may help reduce placental transmission and deleterious effects on
the baby. Pregnant women are also offered advice on avoiding eating under-cooked meat,
and to take good hygiene precautions when handling cats or cleaning litter trays. This is to
prevent them becoming infected during pregnancy.
How common is congenital toxoplasmosis in Wales?
An estimated third of people in the UK will be infected by toxoplasmosis some time during
their lives, however the majority will not be aware of this as they will not experience any
symptoms. When pregnant women are affected there is a risk that the fetus may be
affected – the pregnancy could result in miscarriage, stillbirth or be affected by congenital
anomaly. If a woman develops acute toxoplasmosis during pregnancy, the risk of the
infection reaching the placenta is about 30%.
10 cases of congenital anomaly caused by toxoplasmosis were reported to the CARIS
database between 1998 and 2015. All of these had a confirmed anomaly.
More information
http://www.nhsdirect.wales.nhs.uk/encyclopaedia/t/article/toxoplasmosis/
PARVOVIRUS
What is it?
Parvovirus B19 is a very common infection which affects humans, and usually causes a mild
cold-like illness or no symptoms at all. It affects more children than adults, and is also
known as slapped cheek or fifth disease. People affected usually have a mild illness with a
rash, and in children the rash is most noticeable on their cheeks which can become very red.
It is spread through respiratory infections but can also be spread through blood or blood
products. Parvovirus can be more serious in people with a weakened immune system. It can
be passed to the fetus if the mother is infected in pregnancy and is not already immune to
the virus.
What are the effects on the fetus and baby?
Transplacental transmission occurs in about 25% of susceptible affected women with an
average of 6 weeks between maternal infection and it developing signs in the fetus. Fetal
loss rate, following infection, is estimated at 5-10% and the fetus is most vulnerable during
the second trimester – 13 to 16 weeks gestation is the most critical stage at which health
problems are likely to occur.
Fetal infection affects the bone marrow’s production of red blood cells and results in
anaemia. It can also cause myocarditis. Severe heart problems or anaemia can cause heart
failure and resultant fetal hydrops. Parvovirus B19 is the most common cause of nonimmune fetal hydrops. Sometimes the problems resolve and there are no problems at
birth, but occasionally the condition can lead to fetal death.
How common is parvovirus in Wales?
26 cases of congenital anomalies due to parvovirus have been recorded on the CARIS
database between 1998 and 2015. While parvovirus is a common infection, according to
Orphanet the worldwide prevalence of fetal parvovirus is unknown.
More information
http://www.nhsdirect.wales.nhs.uk/Encyclopaedia/s/article/slappedcheeksyndrome/
http://www.cdc.gov/parvovirusb19/about-parvovirus.html
More information for investigation and management in pregnant women
https://cks.nice.org.uk/parvovirus-b19-infection
VARICELLA INFECTION (CHICKENPOX)
What is it?
Varicella-zoster virus (VZV) is a DNA virus which is quite common and causes chickenpox.
VZV can persist in the body after an initial infection as a latent infection and reactivation of
latent VZV causes shingles. VZV is spread through respiratory infection and through the
conjunctiva. While an effective vaccine against chickenpox is available, it is not part of the
routine childhood immunisation schedule in the UK, but is advised for certain groups seen
as being at higher risk of complications.
More information about the chickenpox vaccine and who should receive it can be found
here :
http://www.nhsdirect.wales.nhs.uk/doityourself/vaccinations/Chickenpoxvaccine/
What are the effects on the fetus and baby?
Maternal infection during the first 28 weeks of pregnancy can lead to intrauterine infection
in about a quarter of cases but in only a very small proportion of these will result in
congenital varicella syndrome in the fetus. The risk varies between 0.4% and 2% with
increasing gestation. The syndrome can comprise low birth weight and severe multisystem
involvement. This includes neurological abnormalities, eye lesions, skeletal anomalies, skin
scarring and limb hypoplasia. An amniocentesis can be done to confirm infection but this
test can be unreliable and carries the risk of miscarriage.
Infections later in pregnancy can cause infant shingles, neonatal chickenpox or the serious
purpura fulminans (disseminated haemorrhagic neonatal chicken pox) which can be fatal.
These sequelae are determined by the gestation at the time of maternal infection.
According to CDC “The onset of maternal varicella from 5 days before to 2 days after delivery
may result in overwhelming infection of the neonate and a fatality rate as high as 30%. This
severe disease is believed to result from fetal exposure to varicella virus without the benefit
of passive maternal antibody.”
Pregnant women themselves are at higher risk of complications from varicella, as a small
percentage go on to develop an associated pneumonia which can be serious.
The Royal College of Obstetricians and Gynaecologists has issued evidence-based guidance
on the management and follow-up of women who contract chickenpox during pregnancy:
https://www.rcog.org.uk/globalassets/documents/guidelines/gtg13.pdf
What is the prevalence in Wales and elsewhere?
Ascertainment of the correct number of pregnancies adversely affected by VZV is
challenging. There were 38 cases recorded on the CARIS database between 1998 and 2015,
however these may have been women who were notified to the CARIS team as they had
contracted chickenpox during pregnancy, but there may not be an associated congenital
anomaly present. International prevalence is unknown.
More information
http://www.nhsdirect.wales.nhs.uk/encyclopaedia/c/article/chickenpox/
Management during pregnancy: https://cks.nice.org.uk/chickenpox#!scenario:1
https://www.cdc.gov/chickenpox/hcp/clinical-overview.html (this is a site from the USA so
any links to information about vaccination will not be relevant)
RUBELLA (GERMAN MEASLES)
What is it?
Rubella virus is a togavirus, transmitted by respiratory secretions. It is a notifiable disease
that causes symptoms that are similar to flu except that the primary symptom is a rash. In
about half of cases the infection may be sub-clinical. Immunisation against rubella is part of
the core childhood immunisation programme in the UK, and rubella vaccine is combined
with mumps and measles vaccine to form the MMR vaccine. Women thinking of becoming
pregnant should ensure they have had two doses of MMR prior to becoming pregnant.
Rubella is usually a mild illness but can have serious consequences for the fetus if contracted
during pregnancy.
What are the effects on the pregnancy and baby?
These are serious as the virus can cross the placenta and infect the fetus, and congenital
infection can affect all organ systems of the body. It has teratogenic properties that affect
the developing cells and can cause Congenital Rubella Syndrome (CRS). The syndrome
consists of cardiac, cerebral, opthalmic and auditory defects. It may also cause prematurity,
low birth weight, neonatal thrombocytopenia, anaemia and hepatitis. Some of the effects of
CRS such as hearing loss or eye problems may not become apparent until a child is aged two
or older.
The risk of major developmental anomalies is highest when infection occurs in the first
trimester – the risk is estimated by the USA Centers for Disease Control (CDC) at about 85%.
Fetal infection can occur throughout the pregnancy but the complications are less severe
the later in pregnancy the infection occurs, and are rare after about 20 weeks gestation.
Antenatal screening for rubella stopped in the UK in 2016. More information about why that
decision was taken can be found here
http://www.antenatalscreening.wales.nhs.uk/public/opendoc/296536
What is the prevalence and rates in Wales?
There were 12 cases of congenital rubella reported in the UK between 2005 and 2015, but
none of these could have been prevented by the screening programme as they were in
women born overseas. There have been no cases of congenital rubella in Wales in the last
10 years and none have been recorded on the CARIS database since 1998.
More information
http://www.wales.nhs.uk/sites3/page.cfm?orgId=457&pid=25242
https://www.cdc.gov/rubella/hcp.html (this is a site from the USA so any links to
information about vaccination will not be relevant)