9- Medical problems in pregnancy (systemic and blood borne infections) Flashcards
rubella is also known as
german measles
Congenital rubella syndrome
is caused by maternal infection with the rubella virus during the first 20 weeks of pregnancy. The risk is highest before ten weeks gestation.
- sensorineural deafness
- congenital cataracts
- congenital heart disease
- growth retardation
- hepatosplenomegaly
- cerebral palsy
why has incidence of rubella dropped
MMR vaccine
when should a women be screened for rubella immunity
if she hasnt had the vaccine or is unsure
antenatal screening for rubella
Two tests were performed:
- IgM antibody – present in acute infection.
- IgG antibody – present following infection or vaccination.
In cases where neither antibody was present, the woman was encouraged to seek rubella vaccination post-delivery (rubella vaccine is a live virus, and should not be administered whilst pregnant).
presentation of maternal rubella
often asymptomatic
non-specific
- malaise
- headache
- coryza
- lymphadenopathy
- fine maculopapular rash
investigations for maternal rubella
In women where rubella infection is suspected, ELISA can be performed to measure rubella specific IgG and IgM:
- IgM antibody – present in acute infection.
- IgG antibody – present following infection or vaccination.
management for a pregnant women with a positive rubella screen
should be immediately referred to a fetal medicine specialist for counselling and further management.
maternal rubella: maternal management
No treatment- self-limiting
- antipyretics
- she should be informed that she is infective from 7 days prior to onset of symptoms and to 4 days after
maternal rubella: fetal management
Congenital rubella syndrome much more likely to occur if contracted <12 weeks
- gestation of infection determines management
management of maternal rubella in pregnancy <12 weeks
high likelihood of defects, it is reasonable to consider a termination of the pregnancy.
management of maternal rubella in pregnancy <12 weeks
high likelihood of defects, it is reasonable to consider a termination of the pregnancy.
management of maternal rubella in pregnancy 12-20 weeks
prenatal diagnosis of fetal rubella infection required. This is usually performed by RT-PCR on amniotic fluid samples.
- If transmission to the fetus is confirmed, management options include termination of pregnancy or ultrasound surveillance to identify features of congenital rubella syndrome (although some features of CRS cannot be detected by ultrasound).
management of maternal rubella in pregnancy >20 weeks
No action required.
congenital rubella syndrome classifcal features can be split into
‘present at birth’ and ‘late onset’.
CRS: present at birth
- Auditory Problems
o Sensorineural deafness - Cardiac Defects
o Pulmonary Stenosis, Patent Ductus Arteriosus, Ventricular Septal Defect - Ophthalmic Defects
o Retinopathy, Congenital Cataracts - Central Nervous System Abnormalities
o Learning disabilities, Microencephaly
CRS: late onset symptoms
- Diabetes mellitus
- Thyroiditis
- Growth Hormone Abnormalities
- Behavioural Disorders
Varicella zoster is a DNA virus responsible for:
- Chickenpox (also known as varicella) – a result of primary infection.
- Shingles (also known as herpes zoster) – a result of viral reactivation.
varicella in pregnancy
- rate due to high levels of immunity in pop
- causes mild illness in children, however if contracted in pregnancy there is increased morbidity and mortality for both mother and foetus
primary varicella zoster presentation
- fever
- malaise
- pruritic maculopaular rash (becomes vesicular and crusts before healing)
- 10-21 day incubation period
- women infectious from 48 hours prior to rash until vesicles have crusted
which complications of varicella zoster infection accounts for the 2% mortality in mothers
pneumonitis , hepatitis, and encephalitis
diagnosis of varicella zoster
clinical diagnosis. if in doubt 2 main investigations:
* Immunofluorescence of basal epithelial cells scrapped from vesicle.
* PCR for varicella zoster DNA.
how to test immunity for varicella zoster
To determine immunity status, women can be tested for IgM and IgG antibodies to varicella zoster. If present, they indicate the woman has immunity against the virus (usually from previous infection or vaccination).
management of varicella zoster: 2 scenarios
1) Women has encountered soemone infectious with varicella zoster
2) women with confirmed varicella zoster
Management: Women has encountered someone infectious with varicella zoster
Determine immunity:
1) Patient describes previous infection: assume immunity and no further action required
2) Patient has no previous infection
- do IgG testing to confirm immunity status
- if <20 week give women varicella zoster immunoglobulin (VZIG) within 10 days of the contact and before the onset of rash
- if >20 weeks then women can receive either VZIG or aciclovir from 7 to 14 days following exposure
management of confirmed maternal chickenpox
Aciclovir (800mg PO 5tds) should be prescribed in patients presenting within 24 hours of rash onset and at >20 weeks gestation. Consider aciclovir prescription in mothers <20 weeks.
The mother should be counselled about the symptoms of pneumonia, neurological signs and haematological rash – and instructed to attend hospital immediately should they occur.
In addition, she should be referred to a fetal medicine specialist, with serial ultrasound examinations beginning at 5 weeks post infection to identify any fetal abnormalities.
Varicella Vaccination
If a woman is found to be seronegative for varicella zoster IgG, pre-pregnancy or postpartum vaccination should be considered. Vaccination is not recommended during pregnancy as a matter of caution.
complications of varicella zoster infections
1) Varicella of the newborn
2) Fetal varicella syndrome
1) Varicella of the newborn
If maternal chickenpox occurs within the last 4 weeks of the pregnancy, there is significant risk (50%) of varicella infection of the newborn. This can be asymptomatic.
The route of infection can be:
- Transplacental
- Vaginal
- Direct contact after birth
ManagementVaricella of the newborn is treated with varicella-zoster immunoglobulin (VZIG) ± aciclovir.