Obstetrics And Perinatal Infections Flashcards
Infections in pregnancy-> neonate
May effect fetal development
Neonatal immune system not fully mature
Different spectrum of infectious agents
Congenital infections may cause long term lie threatening illness
Risk factors modifying outcomes of infection in pregnancy-> mother
Physiological/ immunological changes may increase susceptibility and alter clinical manifestations
Many drugs are contraindicated
Urinary tract infections may be asymptomatic or lead to pyelonephritis
Varicella->develop varicella pneumonia
Maternal rash
-> rubella
-> parvovirus B19-> no congenital risks but in increased risk on mis carriage
Maternal cytomegalovirus
May be primary or secondary-> both cause congenital infection and teal damage
Timing of infection doesn’t appear important
Maternal infection is almost always asymptomatic
Congenital cytomegalovirus
3-4 per 1000
Severe handicap-> 5-10%
minor -> 5%
Prevention of congenital cytomegalovirus
Screening is not advocated
-> no advice to give positive women
-> recurrent CMV may also cause congenital CMV
Development of a vaccine
Congenital rubella
Transplacental transmission
Outcome dependent on timing within pregnancy
-> first trimester-> multiple developmental defects-> congenital rubella syndrome-> CNS, eye, heart
12-18 weeks-> deafness
After 18-> no risk
Universal MMR vaccine
Antenatal screening and post partum vaccination
Investigation of maternal rash
Congenital toxoplasmosis
Toxoplasma Gondi, protozoon
Transplacental transmission
-> brain damage, chorodio retinitis-> may not present until later life
Risk of fetal damage is greatest in early pregnancy
Congenital syphilis
May be multi system
Range of clinical features which present at 5-15
Routine antenatal screening and treatment
Congenital varicella
Varicella embryopathy
Skin loss, scaring, usually unilateral
Impaired limb bud development
Many other less specific features-> microcephaly, cataracts, IUGR 1-2% risk following maternal varicella in first 20 weeks of pregnancy
Blood Bourne virus transmission
Antenataly-> transplacental
Perinataly-> infected birth canal, exposure to maturation blood
Postnatally-> breast milk-> only HIV
Mother to baby HIV
20% risk Preventable by: -> maternal antiretroviral therapy to reduce viral load -> elective Caesarian -> no breast feeding Antenatal screening
Mother to baby HBV
5-90% transmission rate Neonatal infection leads to very high carriage rates Preventable by vaccination -> active-> accelerate course -> passive-> hep B immunoglobin Universal antenatal screening-> HBsAg
Mother to baby HCV
Rates very low compared to hep B
No intervention so no screening
Neonatal septicaemia/meningitis
Main causes-> group B streptococcus, E.coli
Acquired from maternal birth canal/early rupture of membranes leading to chorioamniotits
Known carriers of GBS given antibiotics during labour
Listeria monocytogenes less common
Group B streptococcus
Important causes of neonatal pneumonia, septicaemia and meningitis
Commonly found as normal gut flora
Colonise perineum/vagina in 1/4 of pregnant women
1/200 risk of neonatal infection
I.v antibiotics reduces risk to 1/4000
