Infections in Pregnancy Flashcards
What virus is responsible for chickenpox?
Varicella zoster virus (VSV)
What type of antibody is produced after a primary infection of chickenpox?
IgG
What are the clinical features of chickenpox?
It typically presents with fever, malaise and a pruritic maculopapular rash
The rash characteristically becomes vesicular and crusts before healing
What are the five complications of chickenpox if contracted during pregnancy?
Pneumonia
Hepatitis
Encephalitis
Fetal Varicella Syndrome
Neonatal Varicella Infection
What is the incubation period for chickenpox?
10-21 days
When is chickenpox infectious?
48 hours prior to the rash
UNTIL
The vesicles have crusted, which is usually five to seven days after the rash starts
How to we determine the immunity status of a pregnant woman?
We can collect a blood sample and test for IgM and IgG antibodies to varicella zoster
A positive result indicates immunity against the virus
How do we manage patients who have encountered an infectious person however describe previous primary varicella zoster infection?
No further action is required as they should have immunity
How do we manage patients who have encountered an infectious person however don’t describe previous primary varicella zoster infection?
IgG testing is required to confirm the immunity status
If not immune, the woman should be given zoster immunoglobulin (VZIG) as prophylaxis
This should be given within 10 days of contact.
How do we manage patients who develop chickenpox and present within 24 hours of rash onset (>20 weeks’ gestation)?
We should prescribe oral aciclovir
How do we manage patients who develop chickenpox and present after 24 hours of rash onset (>20 weeks’ gestation)?
We advise symptomatic treatment and hygiene to prevent secondary bacterial infection
What is congenital varicella syndrome?
It is subsequent reactivation of the virus in utero as herpes zoster
When does congenital varicella syndrome occur?
When the fetus is infected by maternal varicella in the first 28 weeks of gestation
What are the four clinical features of congenital varicella syndrome?
Skin Scarring
Eye Defects, such as cataracts and chorioenitis
Limb Hypoplasia, which affects limbs ipsilaterally
Neurological Abnormalities, such as microcephaly and hydrocephalus
In which circumstance is varicella of the newborn at high risk?
If maternal chickenpox occurs within the last 4 weeks of pregnancy
What are the three routes of varicella infection of the newborn?
Transplacental
Vaginal
Direct contact after birth
What is shingles?
Varicella zoster virus reactivation
Can women be infected with chickenpox from individuals with shingles?
Yes
What is parvovirus B19?
Single stranded DNA virus
How is parvovirus B19 transmitted?
Respiratory droplets
Blood
Vertical transmission to the foetus
What are the clinical features of parvovirus B19?
It starts with non-specific viral symptoms, such as malaise, headaches, fever, etc
After 2-5 days, a bright red rash appears diffusely on both cheeks
A few days later a reticular mildly erythematous rash affecting the trunk and limbs appears, which can be raised and itchy
What is the incubation period for parvovirus B19?
4-20 days
When is parvovirus B19 infectious?
From 7-10 days prior to the rash onset
They are not infectious once the rash has appeared
How do we determine the immunity status of a pregnant women to parvovirus B19?
We collect a blood sample and conduct a viral serology, where we check for the presence of IgM antibodies and IgG antibodies
What does the presence of IgM antibodies against parvovirus B19 indicate?
An acute infection within the past four weeks
What does the presence of IgG antibodies against parvovirus B19 indicate?
A long term immunity to the virus after a previous infection
How do we manage parvovirus B19 infection in pregnant patients?
We offer supportive treatment
This involves the conduction of weekly ultrasound scans to monitor for complications and malformations
What are the four complications of parvovirus B19 infection during pregnancy?
Fetal Anaemia
Hydrops Fetalis
Maternal Pre-Eclampsia-Like Syndrome
Miscarriage
How does parvovirus B19 infection cause fetal anaemia?
It is caused by parvovirus infection of the erythroid progenitor cells in the fetal bone marrow and liver
These cells produce red blood cells, and the infection causes them to produce faulty red blood cells that have a shorter life span
Therefore, fetal anaemia develops
What are the four complications of fetal anaemia?
Cardiac failure
Hydrops fetalis
Maternal pre-eclampsia-like syndrome
Fetal death
What is hydrops fetalis?
The abnormal accumulation of fluid in two or more fetal compartments
What is maternal pre-eclampsia-like syndrome?
It involves a triad of hydrops fetalis, placental oedema and maternal oedema
It also features hypertension and proteinuria
What is toxoplasmosis?
It is caused by the parasite Toxoplasma gondii
How is toxoplasmosis transmitted?
It is primarily spread by contamination with cat faeces or the ingestion of undercooked meats
When does toxoplasmosis occur after exposure?
Within three weeks
What are the clinical features of toxoplasmosis?
In most cases, toxoplasmosis is asymptomatic
In cases where patients are symptomatic, they present with mild flu-like symptoms – such as fever, sore throat, coryza and arthralgia
How do we diagnose toxoplasmosis during pregnancy?
We can conduct a PCR analysis of amniotic fluid
This sample of amniotic fluid can be collected via amniocentesis
What is the main complication of toxoplasmosis during pregnancy?
Congenital toxoplasmosis
What is congenital toxoplasmosis?
A disease that occurs when the infection is transmitted from mother to fetus
What are the three clinical features of congenital toxoplasmosis?
Intracranial Calcification
Hydrocephalus
Chorioretinitis
What can congenital toxoplasmosis lead to?
Miscarriage
Stillbirth
When are the complications of congenital toxoplasmosis greatest?
If infection occurs in the third trimester
What is HIV?
An RNA retrovirus that infects and replicates within the human immune system using host CD4 cells
What can HIV lead to without treatment?
Acquired immune deficiency syndrome (AIDS)
How can HIV be transmitted during pregnancy to the fetus?
At delivery
Breastfeeding
Which three infections are tested for during antenatal screening?
HIV
Hepatitis B
Syphilis
What are the four complications of HIV during pregnancy?
Pre-Eclampsia
Miscarriage
Preterm Birth
Low Birth Weight
What do we prescribe to pregnant HIV patients to reduce fetal transmission?
Combined anti-retroviral treatment (cART)
How long do we prescribe cART to HIV pregnant patients?
During pregnancy and delivery
In what three ways does cART reduce the HIV fetal transmission?
It will reduce the viral load to allow for vaginal delivery,
It will reduce the risk of vertical transmission
It will improve the mother’s health
What is the delivery method of HIV pregnant patients based on?
Viral load levels
What delivery method is selected for HIV pregnant patients with a viral load <50 copies/ml?
Normal vaginal delivery
What delivery method is selected for HIV pregnant patients with a viral load >50 copies/ml?
C-section
When do we prescribe IV zidovudine during a c-section (HIV pregnant patients)?
When the viral load is unknown or there are > 10,000 copies/ml
How do we manage babies born from a HIV positive mother postnatally?
Testing
Prophylaxis treatment
What prophylaxis treatment is given to babies born from a HIV positive mother with a viral load < 50 copies per ml?
Zidovudine for four weeks
What prophylaxis treatment is given to babies born from a HIV positive mother with a viral load > 50 copies per ml?
Zidovudine, lamivudine and nevirapine for four weeks
Can HIV positive mothers breastfeed?
No
What is hepatitis B?
An infection of the liver caused by the hepatitis B virus (HBV)
This virus produces E-antigen, which is a protein that is released into circulation to modify the host’s immune system so that it is not detected
What are the three main risk factors of hepatitis B?
Intravenous drug users
Haemophilic patients
Those that live with an infected person
What can be prescribed to pregnant patients to reduce the risk of hepatitis B transmission?
Tenofovir
In which cases do we prescribe tenofovir to hepatitis B pregnant patients?
If they have a high viral load
During which trimester is tenofovir prescribed to hepatitis B pregnant patients?
Third trimester of pregnancy
How does tenofovir treatment reduce the risk of hepatitis B transmission to the fetus?
It will reduce the viral load
What delivery type do we recommend in hepatitis B pregnant patients?
Normal vaginal delivery
What are the three postnatal care treatments for babies born from hepatitis B positive patients?
Immunoglobulin
Vaccination
Hepatitis B Screening
What is immunoglobulin?
An injection given to the baby
When do we give immunoglobulin to babies?
If their mother is positive for hepatitis B and they have a high viral load
How many vaccinations are offered to babies born from hepatitis B patients?
Four in the first year of life
They will then receive a booster with their preschool vaccinations
When is the first hepatitis B vaccination given to babies?
Within 24 hours of birth
When is the second hepatitis B vaccination given to babies?
4 weeks postnatal
When is the third hepatitis B vaccination given to babies?
8 weeks postnatal
When is the fourth hepatitis B vaccination given to babies?
12 months of age
Can hepatitis B positive mothers breastfeed?
Yes as long as the baby has received their first vaccination
When do we test babies for hepatitis B?
After 12 months of age
What is hepatitis C?
It is an infection of the liver caused by the hepatitis C virus (HCV)
This virus is a single stranded, enveloped RNA virus
In which five cases do we screen pregnant patients for hepatitis C?
IVDU use
Substance Misuse
HIV Positive
Hepatitis B Positive
Deranged LFTs
How do we manage hepatitis C infection during pregnancy? Why?
No treatment
This is due to the fact that the drugs used in treatment are teratogenic
How is delivery conducted in hepatitis C patients?
Normal vaginal birth
Can hepatitis C positive mothers breastfeed?
Yes
When do we conduct hepatitis C screening?
Once the baby reaches 18 months
What is syphillis?
A spirochete gram-negative bacteria called Treponema pallidum
How is syphilis transmitted?
A sexually transmitted infection
Vertical, which can be transplacentally or exposure to infected lesions during vaginal birth
What are the five complications of syphilis during pregnancy?
Miscarriage
Stillbirth
Hydrops Fetalis
Growth Restriction
Congenital Infection
How do we manage syphilis during pregnancy?
An intramuscular injection of penicillin
What is the main complication of syphilis?
Congenital syphilis
How long does congenital syphilis take to present?
Five weeks
What are the clinical features of congenital syphilis?
Hutchinson’s triad, which includes…
Deafness
Interstitial Keratitis
Hutchinson’s Teeth
What are the five clinical features of congenital rubella infection?
Sensorineural deafness
Congenital cataracts
Patent ductus arteriosus
Purpuric skin lesions
‘Salt and pepper’ chorioretinitis
