Infections in Pregnancy Flashcards
Give 5 general consequences of perinatal infection
- Maternal illness
- Maternal complications more common in infection (e.g pre-eclampsia with HIV)
- Preterm labour associated with infection
- Vertical transmission –> infection in child, teratogenic in child
- Neurological damage in baby more common with bacterial infection
- Antibiotic usage: can lead to adverse effects in foetus§
What type of virus is CMV?
HHV8
Describe how CMV is spread and its epidemiology in pregnancy
Spread: sexual contact, blood-borne, contact with bodily fluids (saliva, urine etc)
Around 50% of women are immune
What are the main complications of perinatal CMV infection?
- Increased risk of miscarriage/still birth
(Mainly neurological): - Congenital CMV IUGR (intrauterine growth restriction)
- microcephaly, intracerebral calcification, blindness, sensori-neural deafness,
- Hepatosplenomegaly, skin rash, pneumonitis, mental retardation
Can be asymptomatic at birth, infants may present later with blindness, deafness or developmental delay
Common cause of childhood handicap & deafness
Outline the clinical features of CMV infection in the mother
- Often asymptomatic – fever, malaise, fatigue
- Often no other signs of infection
- May have lymphadenopathy
What investigations are indicated for perinatal CMV infection?
- Bloods– CMV IgM or IgG for current infection or immunity
- USS – foetal anomaly scan (e.g microcephaly, growth restriction)
- Other – amniocentesis for CMV PCR – 6-9 weeks after primary infection in mother
Outline the management for perinatal CMV infection
- No treatment to prevent foetal transmission, may offer TOP if evidence of CNS damage/congenital CMV
- Neonatal ganciclovir can attenuate audiological neurodevelopmental problems
What is the prognosis for perinatal CMV infection?
- Rate of transmission to foetus is 40%, 10% of these develop congenital syndrome
- 90% babies symptomatic at birth will later have neurodevelopmental problems
As most maternal infections do not lead to neonatal sequelae, routine screening with invasive amniocentesis is not undertaken
What type of virus is responsible for genital herpes?
Type 2 DNA herpes simplex virus
Describe how HSV is spread, both in primary infection and for vertical transmission
Transmitted via physical/sexual contact
Vertical: transplacental, neonatal transmission at delivery
Risk is 41% with primary lesion or 2% with recurrent lesions
Risk is greatest when the woman acquires a new infection (primary genital herpes) within 6 weeks of delivery
Outline the complications of maternal HSV infection
Neonatal infection is rare, but has a high mortality
Maternal – disseminated herpes (encephalitis, hepatitis, disseminated skin lesions) rare but more common in
pregnancy
Neonatal – 3 subgroups:
• Localised to the skin, eye and mouth
• Local central nervous system disease (encephalitis alone)
• Disseminated infection with multiple organ involvement
Describe how HSV clinically presents in the mother, and indicated investigations
- Burning sensation, pain, pruritus, dysuria, asymptomatic
- Clusters of vesicles with erythema, can progress to ulcerated lesions which crust over
Investigations:
- Clinical history and examination
Outline the management for: antenatal HSV infection, delivery with primary infection, delivery with recurrent infection, neonatal infection
Antenatal – acyclovir 200mg 5x daily for 5 days in primary infection
Delivery with primary infection:
- If within 6 weeks of likely delivery, advise C-section
- If opts for vaginal delivery, give IV acyclovir intrapartum
Delivery with recurrent HSV
- Does not necessitate C-section, women may opt if lesions detected at onset of labour
- Can offer daily acyclovir from 36/40 to reduce likelihood of lesions
Neonatal infection: give acyclovir
What type of virus is VZV and what infections does it cause?
Herpes zoster virus
Causes chickenpox and shingles (reactivation of latent infection)
How is VZV spread?
Respiratory droplet transmission
Transfer to baby can be transplacental, ascending vaginal or contact after delivery with lesions
Outline both maternal and foetal complications of perinatal VZV infection
Maternal – pneumonia risk, encephalitis is rare complication (has 5-10% mortality)
Non-immune pregnant women are more at risk of complications of chicken pox
Foetal:
• Congenital varicella syndrome – skin scarring, limb hypoplasia, muscular atrophy, rudimentary digits, cortical
atrophy, psychomotor retardation, choreoretinitis, cataracts
• Neonatal varicella – severe disseminated haemorrhagic neonatal VZV – purpura fulminans has 30% mortality
if untreated
Describe the clinical presentation of perinatal VZV infection and the indicated investigations
- Prodromal fever, malaise, myalgia (adults > children)
- Centripetal maculopapular rash mainly in areas not exposed to pressure. Vesicular rash appearing in crops
Investigations:
• Can send vesicular fluid for VZV PCR, electron microscopy (not serology)
When is there greatest risk of neonatal VZV infection?
- Teratogenicity: rare but consequence of early pregnancy infection
- Maternal infection in 4 weeks preceding delivery
- If delivery occurs within 5 days after or 2 days before maternal symptoms
Outline the management for perinatal VZV infection (non-immune women with exposure, maternal infection, maternal infection around time of delivery)
- Ask if woman has had chickenpox previously, VZV IgG is marker for immunity
Ig for prevention, aciclovir for treatment
Non-immune women exposed to chickenpox:
- VZ immunoglobulin given ASAP (effective if given up to 10 days after contact)
If infection occurs:
- Avoid contact with other pregnant women and neonates until the lesions have crusted over
- Aciclovir within 72hrs of rash appearing (N.B VZIG is ineffective once chickenpox has developed)
Maternal infection around time of delivery:
- VZIG for neonate
- Monitor neonate for signs of infection, until 28 days after onset of maternal infection
- Neonatal infection: give acyclovir
Ideally vaccinated pre-conception if non-immune, can vaccinate post-partum also
Outline the epidemiology of perinatal rubella infection
Rare (due to MMR immunisation): 97% of women in the UK are vaccinated
Outline the clinical presentation of maternal rubella infection
- Fever, malaise, coryzal symptoms (cold-like symptoms), arthralgia, rash
- Lymphadenopathy, maculopapular rash (usually starting behind the ears, spreadingto head and neck, then to rest of body)
Describe the required investigations to diagnose maternal rubella infection
- Bloods – rubella serology IgM (active), IgG (immune)
* USS – foetal anomaly
Outline the complications of perinatal rubella infection, including when the risk to the foetus is greatest
• Maternal – miscarriage, pneumonia, arthropathy, encephalitis, ITP
• Foetal – death
- Congenital rubella syndrome: deafness, VSD, PDA, cataracts, CNS defects, IUGR, hepatosplenomegaly, thrombocytopenia, rash
Highest risk of congenital rubella syndrome is in first trimester (90%), then around 5-10% risk 14-16/40, risk after 20/40 is very low
Outline the management and screening options in perinatal rubella infection
Non-immune women develops rubella <16/40: TOP is offered
Screening
- No longer routinely offered in UK (as levels are v low)
- Screening would identify those in need of vaccination following pregnancy (as live vaccine is contraindicated during pregnancy)
Outline the epidemiology of perinatal parvovirus B19 infection
0.25% of pregnant women
50% of women are immune
During which gestation period is vertical transmission most likely?
Risk period for foetal transmission is between 4-20/40
No transmission before 4/40
Low risk of foetal hydrops after 20/40
