Infectious Diseases in Pregnancy

Question 1

definition of rubella (transmission, incubation, infectious period)

Answer 1

RNA togavirus
transmission: respiratory droplets - highly infectious
incubation: 14-21 days
infectious period: 7 days before & after rash

Question 2

symptoms of rubella

Answer 2

asymptomatic in 25 to 50 % of cases
mild, febrile illness
macpap rash
arthralgia
lymphadenopathy - post-auricular and sub-occipital nodes
rare: neurological, thrombocytopenia

Question 3

diagnosis of rubella

Answer 3

serological confirmation w paired sample: acute & convalescent phase (10-14d later)

1) appearance of IgM Abs
2) > 4 fold increase in IgG titres/increased activity

Question 4

congenital defects associated w rubella

Answer 4

microcephaly & mental retardation
sensorineural deafness
eye: cataracts, retinopathy, glaucoma, strabismus, micropthalmos
cardiac abnormalities: VSD, PDA

later: DM, thyroid, progressive panencephalitis

Question 5

risk of congenital defects in rubella

Answer 5

rare after 20 weeks

Question 6

foetal diagnosis of rubella

Answer 6

amniocentesis or cordocentesis performed 6 weeks after maternal infection: rubella PCR, culture & foetal IgM

Question 7

managing the rubella neonate

Answer 7

1) cord blood/heel prick IgM serology
2) maternal serology
3) urine, pharyngeal & conjunctivial swab for PCR
4) placenta to histopath
5) supportive Mx

Question 8

definition of parvovirus (transmission, incubation, infectious period)

Answer 8

ssDNA - lyses human RBCs

route: direct contact w respiratory secretions, vertical transmission, transfusion of blood & blood products

Question 9

symptoms of parvovirus

Answer 9

30-40% is subclinical
erythema infectiosum
rubella like rash (macpap)
arthralgia

Question 10

foetal effects of parvovirus

Answer 10

+/- foetal hydrops - 5 weeks after maternal infection

foetal anaemia

Question 11

management of congenital parvovirus infection

Answer 11

nil intervention - monitor w US every 1-2 weeks for 12 weeks to assess for hydrops

Question 12

GBS

Answer 12

Streptococcus agalactiae: Gram positive coccus w tendency to form chains

Question 13

who requires GBS prophylaxis during labour? - name 8

Answer 13

1) positive swab at 36 weeks
2) SROM < 37 weeks
3) ROM > 18 hrs
4) fever > 38 degrees
5) previous sibling w EOGBS
6) known carriage of GBS in current pregnancy
7) clinical diagnosis of chorioamnionitis
8) other twin w current GBS

Question 14

GBS prophylaxis

Answer 14

IV penicillin 3g STAT dose, then 1.3 g every 6 hours thereafter

ONLY WHEN ROM occurs (i.e. not for elective LSCS)

Question 15

definition of cytomegalovirus (transmission, incubation, infectious period)

Answer 15

beta herpes virus

route: sex, blood, vertical

Question 16

symptoms of CMV (maternal)

Answer 16

mononucleosis like
GIT Sx
abnormal LFTs/rashes

Question 17

symptoms of congenital CMV

Answer 17

microcephaly
hydrops foetalis: ascites, pleural effusion
IUGR
intracranial calcifications
acute visceraldisease

Question 18

risk of CMV congenital transission

Answer 18

50% risk (unless its a maternal reactivation, then 1%)

Question 19

neonatal sequalae of CMV

Answer 19

mental retardation
microcephaly
chorioretinitis
hearing loss