Infectious Diseases in Pregnanct Flashcards
What are prenatal infections?
Infection acquired/carried by the mother and transmitted to the developing fetus
What are perinatal infections?
Infection transmitted around the time of delivery
What are some complications of chickenpox?
Secondary bacterial infection - Staph, strep
Pneumonitis - particularly maternal
Acute cellular ataxis
What manifestations of varicella do we worry about around pregnancy?
Severe maternal illness
2nd and 3rd Trimester - fetal anomalies
Perinatal infections
How do mothers die from varicella?
Severe pneumonitis, particularly during third trimester
What is the pathophysiology of congenital varicella syndrome?
Zoster reactivation in the fetus
What is the risk of developing CVS?
2-12 weeks: 0.55%
12-28 weeks: 1.4%
How does perinatal varicella occur?
Primary maternal varicella -7 to +2 days from delivery
- 17-30% rate of transmission to baby
How do you treat varicella exposure?
If known exposure, no worries
If unknown exposure status
- Test IgG status, if non-immune give VZIG with 96 hours to 10ds
Also give VZIG to preterm baby if exposed
Can you give varicella vaccine in pregnancy?
No, live dose
What types of CMV infections are there?
Primary
Reactivation
New primary of different strain
What is the most common fetal infection?
CMV
What is the pathophysiology of CMV in neonates?
90% asymptomatic - 10-15% long term sequelae
10% Symptomatic - 80-100% long term sequelae
How helpful is CMV IgM?
Not very, doesn’t only occur in primary infection
Which anti-virals are used in CMV?
Ganciclovir
Valganciclovir - oral
For 6 months
What problems does influenza cause in pregnancy?
Maternal - viral pneumonitis or secondary bac pneumonia (particularly third trimester) Premature birth ?Early and late fetal death ?Congenital neurological defects Fever - indirect teratogenic effect
What proportion of mothers are carriers of GBS?
15-25%
How does GBS get to the baby?
Up the vagina
During delivery
How does GBS present?
Early onset - 1-2 days
- Pneumonia, septicaemia
Later onset
- Meningitis
How do we predict GBS infection?
Identify risk factors
Swab at 35-37 weeks
How is GBS screened for?
At 35-37 weeks
Vaginal and anal swab
When are abx for GBS given?
4 hours prior to delivery
What abx for are given for GBS?
Penicillin
If allergic
- If rash: cephazolin
- If anaphylactic: Clindamycin or vancomycin
When does hepatitis B transmission occur?
Usually labour and birth
How do you predict the chance of transmission in Hep B positive mother?
eAg
Viral titre
sAg
How do you prevent maternal transmission?
Vaccine
and Immunoglobulin
Anti-viral therapy in third trimester
How do you confirm Hep C status? Why?
HCV RNA
Ab positivity continues after cure
How do you reduce risk of Hep C transmission?
Delay IM injections until after washing the baby
How is parvo transmitted?
Respiratory
Vertical
Blood products
What are complications of maternal primary parvo infection? What is the pathophysiology?
Fetal hydrops - 3%
Fetal death - 0.6%
Anaemia and heart failure
How do you manage maternal parvo?
Weekly US
Treat anaemia
How does rubella present?
Low-grade fever Lymphadenopathy (95%) – occipital, postauricular, posterior cervical Exanthem –maculopapular; face > trunk >limbs Polyarthralgia / arthritis
When is the baby must susceptible?
1st trimester
What is the classical triad of congenital rubella?
- Ophthalmological – cataracts, glaucoma, retinopathy
- Cardiac – PDA, PA stenosis
- Auditory – sensorineural deafness
Do you vaccinate for rubella in pregnancy?
No, it’s live
Which infections are teratogenic?
TORCH Parvo Varicella Syphilis Zika
How do you manage a fever in pregnancy?
Lower the fever - panadol
+/- steroids
+/- tocolytics
+/- abx
What are the ddx for fetal hydrops?
Alloimmunisation Infections - CMV - Parvo Congenital - Heart failure due to structural/rhythm disturbance - Aneuploidy Anaemia - Thalassaemia - Aneuploidy
How do you investigate for Parvo?
IgM and IgG testing over a period of time
- compare to previous samples that are stored
How do you ix fetal hydrops?
Cord sampling and blood testing
- Parvo serology
Cross match with mother’s blood
