Infections in pregnancy - finish! Flashcards
what is the pathophysiology of rubella in pregnancy?
In first 8-10 weeks risk of damage to fetus is as high as 90%
- Congenital rubella syndrome → rubella togavirus in first 20 weeks of pregnancy
- transmission through respiratory droplets or aerosols
- risk highest before 10 weeks gestation
what is the significance of the vaccine in rubella?
- check rubella antibodies
- vaccinatedwith two doses of the MMR, three months apart
- pregnant women should not receive MMR as live vaccine
- non-immune → offer after birth
what are some clinical features of rubella?
- fever
- coryza
- arthralgia
- rash which begins on face and moves to trunk
- lymphadenopathy: post auricular
how do you investigate and manage rubella?
*serological testing: rubella-specific IgM or significant risk in rubella specific IgG
- supportive
- isolate to prevent spread
- discuss with local health protection unit
what are some features of congenital rubella?
- Congenital sensorineural deafness
- Congenital cataracts
- Congenital heart disease (PDA and pulmonary stenosis)
- Growth retardation
- Learning disability
what is the pathophysiology of chicken pox?
varicella zoster virus (VZV)
- incubation period for the virus is10-21 days
- woman is infectious from 48 hours prior to the rash to until the vesicles have crusted
what is the significance of exposure during pregnancy?
- safe if previously had
- When they are not sure about their immunity, test the VZV IgG levels. If positive, they are safe
- When they are not immune, they can be treated withIV varicella immunoglobulinsas prophylaxis against developing chickenpox
- This should be given within ten days of exposure.
- Infection is associated with pneumonia, hepatitis, and encephalitis – accounting for the2% mortalityin mother
how do you manage a suspected contact?
less than 20 weeksgestation, the woman should receivevaricella zoster immunoglobulin (VZIG)within 10 days of the contact, and before the onset of rash
more than 20 weeks gestation, the woman can receive eitherVZIG, or alternativelyAciclovircan be given from days 7 to 14 following exposure
how do you manage maternal chicken pox?
- aciclovir within 24h of rash at >20w, consider in those <20 w
- counselled about the symptoms ofpneumonia, neurological signs and haematological rash - attend hosp
- fetal medicine specialist, withserial ultrasound examinationsbeginning at 5 weeks post infection to identify any fetal abnormalities
what are some complications for mother and baby in chicken pox?
- More severe cases in the mother, such asvaricellapneumonitis,hepatitisorencephalitis
- Fetal varicella syndrome
- Severeneonatal varicella infection(if infected around delivery)
what is the route of infection for the newborn?
transplacental, vaginal, direct contact after birth
mx: varicella-zoster immunoglobulin (VZIG) ± aciclovir
what is congenital varicella syndrome?
- reactivation of the virus in utero as herpes zoster - fetus is infected by maternal varicella before 20 weeks gestation
- Fetal growth restriction
- Microcephaly, hydrocephalus and learning disability
- Scars and significant skin changes located in specificdermatomes
- Limbhypoplasia(underdeveloped limbs)
- Cataracts and inflammation in the eye (chorioretinitis)
what is the pathophysiology of parvovirus infection?
- Parvovirus B19 virus - ‘fifth disease, slapped cheek syndrome, erythema infectiosum’
- self limiting, rash and sx fade over 1-2w
- infectious 7 to 10 days before rash
- not once rash
- significant exposure → 15 min in same room, face to face contact
how does parvovirus present?
- non-specific viral
- 2-5 days later rash
- quite rapidly as a diffuse bright red rash on both cheeks
- few days later - reticular(net-like) mildly erythematous rash affecting the trunk and limbs appears, which can be raised and itchy
how is parvovirus investigated and managed?
- IgM to parvovirus → acute infection within the past four weeks
- IgG to parvovirus → long term immunity to the virus after a previous infection
- Rubella antibodies (as a differential diagnosis)
- supportive
- Women with parvovirus B19 infection need a referral tofetal medicineto monitor for complications and malformation
