Effects of Infections in Early Pregnacy Flashcards
What are the 2 ways to think of pregnancy in terms of infections?
- relative immuno-suppression
- physiological changes in mother
Which infections are harmful to the mother?
Influenza
Which infections are harmful to the fetus?
Toxoplasmosis HSV Syphilis Parovirus B19 CMV Rubella
Which infections are harmful to the mother and foetus?
Hepatitis (A, E, B, C)
VZV
HIV
How should you remember the main infections?
TORCHES Toxoplasmosis Other (influenza, parovirus B19) Rubella Cytomegalovirus (CMV) Herpes Simplex Virus, HIV, Hepatitis
How do you diagnose infection in pregnancy?
- look for pathogen itself (PCR to detect viral DNA or RNA, very sensitive)
- look for immune response to it (early IgM rise followed by IgG rise)
What is the footprint of infection?
IgG signifies part infection and is protective in many cases
What is cytomegalovirus?
CMV
- very common (50% adults have past exposure)
- primary infection subclinical
How is CMV transmitted?
Saliva
Blood/blood products
Sexual intercourse
Organ transplantation
When can CMV occur?
Any time during pregnancy
- primary infection more likely to cause congenital CM and will be most likely in 1st trimester of pregnancy
How to diagnose CMV?
Maternal serology - CM IgG and IgM
Neonatal urine/saliva - CMV DNA PCR
What are the wide range symptoms of CMV?
Severe - intra uterine growth retardation (non specific)
Hepatosplenomegaly
Microcephaly
Sensorineural deafness
What is the significance of deafness and CMV?
- commonest congenital cause of sensorineural hearing loss
What is Varicella Zoster Virus?
Chicken Pox
- Most adults immune
- Lower % in tropical climates
- extremely infectious via droplet/airborne
- 1 person infects 10-12 susceptible individuals
What does the risk association of Varicella Zoster Virus depend on?
- mother: worse the later
- foetus: more complicated
How is Varicella Zoster virus diagnosed?
Clinical syndrome
Swab of vesicle fluid
Maternal serology
How is Varicella Zoster virus prevented?
if known mother is IgG negative:
- VZ immunoglobulin (post exposure)
- Vaccination (pre-exposure)
How is Varicella Zoster virus treated?
- valaciclovir
- safe during pregnancy
What is shingles?
Reactivation of chicken pox in a nerve root
- doesn’t cross midline
When is there high risk of congenital varicella syndrome?
- higher in second trimester
What are the symptoms of congenital varicella syndrome?
- skin lesions (limb hypoplasia)
- CNS (microcephaly, hydrocephaly, neurodevelopmental delay)
- cataracts/eye problems
- GI, genitourinary and cardiac abnormalities
What is the risk of neonatal varicella?
- much higher than congenital
- during birth/just after deliver
What is herpes simplex virus?
- extremely common
- HSV2 related to sexual activity
- associated with wide spectrum of disease (genital/oral ulceration, CNS infection)
How does neonatal HSV infection arise?
- while passing through birth canal
- if adults kiss child
- if not treated = infection
How is neonatal HSV infection diagnosed?
- clinical
- HSV DNA PCR neonate blood
- vesicle swab
- maternal vesicle swab
How is neonatal HSV managed?
Aciclovir treatment
- reduces mortality
What is rubella?
- uncommon
- most of population have antibodies to rubella
- self limiting outside of pregnancy = rash, lymphadenopathy
- in pregnancy dangerous
- no treatment
How is rubella diagnosed?
- serology
- oral fluid PCR
What are the risks of congenital rubella?
- greater earlier there is contraction RISK OF - microcephaly - heart disease - petechiae and purpura
What is Parovirus B19?
- slapped cheek disease
- erythrocytes are cellular target
- most adults have past exposure
How is parovirus diagnosed?
- maternal serology/PCR
- fetal ultrasound
At 0-20 weeks what is the risk of fetal loss?
9%
At 9-20 weeks what is the risk to the fetus?
3% risk of hydrops fetalis (heart failure) as has to work harder to produce Hb
At >20 weeks what is the risk to the fetus?
Negligible
What is toxoplasmosis?
- due to parasite toxoplasma gondii
- natural host is cat
- humans intermediate host through ingestion of oocyst (contact with cat feaces or eating infected meat)
What is the risk of congenital toxoplasmosis?
- lowest if maternal infection occurs in 1st trimester
- risk to foetus greatest during 1st trimester
What are the clinical features of congenital toxoplasmosis?
IUGR Hydrocephalus Cerebral calcification Microcephaly Hepatosplenomegaly
How is congenital toxoplasmosis diagnosed?
Maternal serology
Amniotic fluid
PCR
How is congenital toxoplasmosis prevented?
- no vaccine
- avoidance behaviour only (no gardening, don’t handle cat little, avoid uncooked meats)
What is syphilis?
- STI
- due to spirochete Treponema pallidum
- common
- highest risk during 1st trimester or peripartum
- associated with miscarriage/still birth/prematurity
How is syphilis diagnosed?
Clinical syndrome and serology
How is syphilis treated?
Penicillin
What are the clinical features of early congenital syphilis?
early 0 to 2 years:
- rash
- rhinorrhoea
- osteochondritis
- perioral fissures
- lymphadenopathy
What are the clinical features of late congenital syphilis?
Late >2 years
- Hutchinson’s teeth
- Clutton’s joints
- high arched palate
- deafness
- saddle nose deformity
- frontal bossing
What is looked for during antenatal screening?
Week 12
HBV, HIV, Syphilis, CMV/toxoplasmosa, VZV
- regular US to monitor foetal development
When can termination of pregnancy be offered?
Before 24 weeks
