Infections in pregnancy Flashcards
what are the possible consequences for antenatal infection
Maternal illness
Maternal complications
Preterm labour
Vertical transmission
Neurological issues with the foetus
Antibiotic use in pregnancy presents several risks
What are viruses that may cause issues during pregnancy
HSV CMV HZV Rubella Parovirus Hep B/C HIV Influenza Zika
what are the foetal/anenatal complications of CMV infection
Vertical transmission in 40%
10% are symptomatic at birth, with IUGR, pneumonia and thrombocytopenia
Most have a risk of serious neurological sequalae (hearing impairment, mental impairment, visual impairment)
Asymptomatic neonates (15%) are at risk of deafness
how do you diagnose antenatal CMV infection in the mother and/or baby
USS abnormalies are present in 20% of foetuses (intrahepatic/intracranial calcification)
Maternal blood testing may provide an answer to maternal infection:
CMV IgM stays +ve long after infection – may predate pregnancy
Titres
IgG avidity (how strongly antibodies bind to the antigen) is low in acute infection, and allows differentiation
If maternal infection is confirmed, amniocentesis 6 weeks after confirmation of maternal infection will test for vertical transmission
how do you manage antenatal CMV infection
Most infected neonates are not seriously affected
No screening programme is currently in place
No vaccine exists
No prenatal treatment and termination may be offered
USS can determine those most at risk
how is HSV usually transmitted to a neonate
from mother if she has genital herpes during labour
what are the foetal defects associated with HSV infection
Not teratogenic
Foetal infection is rare but has High mortality
Usually from a recent maternal infection, meaning the foetus won’t have passive immunity from maternal antibodies
how do you diagnose a maternal HSV infection
swabs technically but it tends to be pretty obvious clinically when examining the mother
how do you manage antenatal Herpes Simplex Virus infection
Referral to GUM
C-section reccomended to anyone delivering 6 weeks within a primary infection
There is a lower risk in recurrent herpes so c section is not advised
3rd trimester aciclovir may reduce the frequency of recurrences at term
Exposed neonates are given aciclovir
what are the foetal defects associated with antenatal HZV infection
Teratogenicity is rare (1-2%) in early pregnancy if treated immediately with oral aciclovir
Maternal infection up to 4 weeks preceding delivery can cause severe foteal/neonatal infection
how do you manage an antenatal HZV infection
Immunoglobin used to prevent
Aciclovir used to treat
Pregnancy women exposed to zoster are tested for immunity and given immunoglobins within 10 days if not immune, or aciclovir if infected
Foetuses born 5 days after maternal signs of infection, or 2 days before, are given immunoglobins and aciclovir
Immunisation is possible
what is the pathology of rubella
normall affects children causing a mild fever and a widespread maculopapular rash
extremely rare in UK, <10 in UK
what foetal defects are associated with antenatal rubella infection
early infection:
Cardiac abnormalities
Eye problems
Mental retardation
Deafness
complications reduce later on in pregnancy
how do you manag/prevent rubella infection in pregnancy
Screening is routine at booking visit
<16 weeks infection, termination is offered
Vaccine is live and contraindicated in pregnancy
what is the pathology of parovirus
‘slapped cheek’ presentation +/- arthralgia in kids
what foetal defects are associated with antenatal parovirus infection
Suppresses foetal EPO causing anaemia
Variable degrees of thrombocytopenia may also be caused
Foetal death occurs In 10% of pregnancies, usually ones that are below 20 weeks
how do you diagnose antenatal parovirus infection
+ve IgM testing prompts foetal surveilance
Anaemia may be detected on USS by increased foetal blood flow through its MCA
There may also be subsequent oedema from cardiac failure (hydrops)
Spontaneous resolution occurs in 50%
how do you manage antenatal parovirus infection
Infected are scanned regularly to screen for hydrops/anaemia
If severe, transfusion can be given
Excellent prognosis in survivors
what is the pathology of Hep b infection
Transfer by blood products or sexual activity
Resolves in 90%, persists in 10%
Hep B surface antibody +ve people are of low infectious risk
Hep B surface antigen +ve people are of higher risk, along with HBeAG +ve
what are the foetal complications of antenatal hep B infection
90% become chronic carriers
how do you diagnose antenatal hep B infection?
maternal screening
what is the management of antenatal hep B infection?
Csection, avoiding breastfeeding and immunoglobins do not prevent vertical transmission
Screening is restricted to high-risk groups
Antivirals may be used
What does the maternal infection screening test done at the booking (10 week) visit test for
HIV
Syphilis
Hep B
How is HZV screened for in pregnancy?
based on history (have you had chickenpox) or blood tests (serum antibodies) - if there is no immunity immunoglobulins are recommended
