Effects of Infection in Early Pregnancy Flashcards
Why are pregnant women more at risk of infection
- pregnancy is an immunosuppressive state
- physiological changes to the mothers body
describe why pregnant women are more at risk of infection
- Relative immune-suppression – pregnancy is relatively immunosuppressed state, certain conditions are for some reason a lot worse in pregnancy than others for example Hep E this carries a 25-30% mortality risk, this is significant in the regions of the word where this happens
- Physiological changes in mother - pregnant women who get influenza have a worse outcome than non-pregnant women, this is not an immunological reason but is because of anatomy reasons this puts pressure of the diagram and reduces the overall expansion of the lungs therefore this reduces the spread
What infections are
- harmful to the mother
- harmful to the foetus
- harmful to both
Harmful to the mother
- Influenzas
harmful to the foetus
- Toxoplasmosis
- HSV
- Syphilis
- Parvovirus B19
- CMV
- Rubella
Harmful to both
- VZV
- HIV
- Hepatitis A/E/B/C
What does TORCHES stand for
Toxoplasmosis Other Rubella Cytomegalovirus (CMV) Hepres Simple virus
What is toxoplasmosis
a disease that results from infection with the Toxoplasma gondii parasite,
How do we diagnose infection in pregnancy
Serology and PCR
what do you look at in serology
- Look at IgM and IgG
what is the difference between IgM and IgG
- IgM is the antibody that goes up in an acute infection and then goes down
- IgG is a memory antibody so evidence of IgG signifies a past infection and is protective in many cases
what happens at 10 weeks
- all serologies get tested
- therefore you have a baseline at that moment in time as to what infections you have previously had
- have blood tests to compare it to if you become infected later
how do you use PCR
- DNA and RNA is present in viruses
- Can find a bit of DNA or RNA you can amplify it and match it against the database and diagnose it
how common is CMV
- VERY COMMON
- 50% OF UK adults
What type of virus is CMV
Herpes virdae virus
What does CMV stand for
Cytomegalovirus
describe how CMV can cause flairs
A flair is a reactivation of CMV can happen at points of stress or at any time in your life
- if it happens during pregnancy it will spread to the baby and cause problems
what vaccine is used to prevent chicken pox
VZV vaccine
How does the transmission of CMV happen
via saliva, blood or blood products, sexual intercourse, organ transplantation or via mother
what is a primary infection of CMV likely to cause
congenial CMV - this is because the viral load is higher therefore the chance of transferring the virus to the foetus
- more likely to happen in the 1st trimester of pregnancy
What is the prevalence of congenital CMV
~ 7 per 1000 live births (0.7%)
• only 13% of babies with congenital CMV are symptomatic
How do you diagnose CMV
- maternal serology CMV IgG and IgM
- neonatal urine/saliva for CMV DNA PCR test and look directly for the virus
- blood, saliva and urine
What are the symptoms of CMV
- severe: Intra Uterine Growth Retardation (IUGR), hepatosplenomegaly, microcephaly
- sensorineural deafness
What is the main symptom affect of CMV
sensorineural deafness
why do you not do a serology test on babies in the first 6 months of life and while they are breastfeeding
because they do not have their own antibodies
what is the commonest cause of congenital sensorineural hearing loss
CMV
What is the heel prick test
- Can be stored for life
- used to mark specific disease
disease
- sickle cell disease
- cystic fibrosis
- congenital hypothyroidism
- PKU
- MCADD
- MSUD
what does the VZV virus cause
Chicken pox
how many people are now immune to VZV
• 80-90% UK adults are immune to VZV i.e. VZV IgG positive
how infectious is VZV
- extremely infectious – droplet/airborne
* 1 person can infect 10-12 susceptible individuals
what is RO
- the number of people that one sick person will infect on average is called Ro
How do you diagnose VZV
- clinical syndrome
- swab of vesicle fluids (viral PCR)
- maternal serology
how do you manage VZV
- prevention
- varicella zoster immunoglobulin (post exposure)
- vaccination (pre exposure)
Treatment (val) acyclovir – safe during pregnancy
What are the risks of VZV in the 1st and 2nd trimester
1st: 0.5%, 2nd: 1.4%
what are the effects of congenital varicella syndrome
Skin lesions (73%) • leading to limb hypoplasia
CNS (62%)
• microcephaly, hydrocephaly, neurodevelopmental delay
• cataracts/other eye problems
- also GI, genitourinary & cardiac abnormalities
- miscarriage
what happens in neonatal varicella
- mother has VZV around the time of delivery
- most severe if 5 days before to 2 days after delivery
- can be extremely severe/even fatal
- neonate should receive VZIG and acyclovir
What is the treatment for neonatal varicella
• neonate should receive VZIG and acyclovir
when do you transmit neonatal VZV to the neonate
- 7 days before delivery and 7 days after
what are the two types of HSV viruses
oral - HSV1
Genital herpes - HSV2
When do you get neonatal HSV infection
- most likely to get it through vertical transmission at the time of delivery, this is a direct infection at the time of delivery
- be caused by primary HSV2 infection at delivery
How do you diagnose neonatal HSV infection
clinical, HSV DNA PCR neonate blood/vesicle swab/maternal vesicle swab
how do you treat neonatal HSV infection
• mortality (untreated) 65% mortality reduced to 25% with aciclovir treatment
What are the symptoms of rubella
rash, lymphadenopathy, arthralgia
How do you diagnose rubella
serology/oral fluid PCR
what is the treatment for rubella
No available treatment
describe the congenial risk of rubella
• also 20% risk of foetal loss if < 20 weeks
what does MMR affect against
- 2 doses considered to provide lifelong protection against 3 viruses:
- Measles Mumps Rubella
what is parvovirus B19
Primate erythroparvovirus
- IT AFFECTS THE RED BLOOD CELLS
how do you diagnose paravirus B19
maternal serology/PCR, fetal ultrasound
what complications can Paravirus B19 cause
miscarriages, intrauterine growth restriction
What is the risk of pregnancy in parvovirus B19
- 0-20 weeks: 9% risk of fetal loss
- 9-20 weeks: 3% risk of hydrops fetalis
- > 20 weeks: negligible risk
What is amniocentesis and how does it work
- Take ammonitic fluid from the room, gold standard for diagnosing congenital pregnancy
- Then do PCR on the fluid
- Risk of 1% miscarriage specialist investigation only be done when all the risks are fully disclosed
what is toxoplasmosis
• infection due to parasite Toxoplasma gondii
What is the natural host of toxoplasmosis and how does it spread
- humans are an intermediate host through ingestion of oocysts
- either via contact with cat faeces
- or eating infected meat
what does toxoplasmosis cause
• IUGR
- hydrocephalus,
- cerebral calcification
- microcephaly
- hepatosplenomegaly
What are the risk factors for acquiring toxoplasma gondii
- cat ownership
- gardening
- eating raw meat
- eating cured meat
What is the treatment of toxoplasmosis
- spyramicin, pyrimethamine/sulfadiazine/folinic acid
* depends on trimester
How do you prevent toxoplasmosis
- no vaccine
- avoidance behaviour only:
- no gardening
- don’t handle cat litter
- avoid uncooked meats or cured meats
- hand hygiene
What is syphilis
• sexually transmitted infection due to spirochete Treponema pallidum
How do you diagnose syphilis
clinical syndrome and serology
when are you at high risk of transmission of syphilis
• highest risk of transmission during 1st trimester or peripartum
What is the affect of syphilis on birth
• miscarriage/still birth/prematurity
How do you treat syphilis
- Penicillin
What are the symptoms of congenial syphilis
- Early i.e. 0 to 2 years
- rash
- rhinorrhoea
- osteochondritis
- perioral fissures
- lymphadenopathy
- GN
- Late i.e. > 2 years
- Hutchinson’s teeth
- Clutton’s joints
- high arched palate
- deafness
- saddle nose deformity
- frontal bossing
What is permpartum sepsis
infection of retained products of conception, chorioamnionitis
what does Group B strep increase risk of
neonatal sepsis
What are the ethical issues surrounding infection and screening
- antenatal screening allows early detection of high risk pregnancies
- serology can be difficult to interpret
- retrospective testing for TORCH infections may lead to:
- further diagnostic procedures e.g. amniocentesis
- decisions regarding continuation of pregnancy
- often no treatment is available
