Infections in Pregnancy Flashcards
What are the TORCH infections
Toxoplasmosis
Other (syphilis, parvovirus B19, hep B/C, listeriosis, VZV, HIV, GBS)
Rubella
CMV
HSV
What is toxoplasmosis and how is it transmitted
Protozoan toxoplasma gondii with reservoir in the domestic cat
Indigestion of raw or undercooked meat containing cysts
Infectious oocytes presented in contaminated water/soil
Increased risk of vertical transmission with increasing gestational age (5% 1st, 80% 3rd trimester)
Risk of congenital toxoplasmosis reduced with increasing gestational age (60-80% 1st, 5% 3rd)
Only seroconversion places risk to the foetus, occurring in 2 weeks
IgG detectable 1-2 weeks after infection
What are the clinical features of toxoplasmosis in the mother and foetus
Mother: asymptomatic or fever, malaise, arthralgia
Child:
60% asymptomatic at birth → deafness, low IQ, microcephaly
- Chorioretinitis (→ cataracts)
- Convulsions
- Hydrocephalus (microcephaly)
- Intracranial (‘tram-like’) calcifications - Scattered throughout the brain (unlike CMV, which is peri-ventricular)
- Hepatosplenomegaly/jaundice
What investigations should be done for toxoplasmosis
Bloods: Sabin Feldmen Dye test, IgM and IgG serology
Other:
- US foetal anomaly scan: FGR, microcephaly, ventriculomegaly, ascites
- Amniocentesis and PCR
What is the management for toxoplasmosis
Prevention: Mother should avoid eating raw/rare meat and handling cats and cat litter
Toxoplasmosis PCR +ve in mother, -ve in baby→ Spiramycin (3-week course, 2-3g/day) - prevents vertical transmission
Toxoplasmosis PCR +ve in mother, +ve in baby → Pyrimethamine + Sulfadiazine
- Treat baby for up to 1 year after delivery (if no TOP)
Adjunct: Prednisolone
What is rubella and how is it transmitted
RNA virus from togaviridae family
Outbreaks from migrants where vaccination programmes do not exist
Vertical infection during maternal varicaemia 5-7d post exposure
90% chance of virus being passed to the foetus if Rubella infection is in early pregnancy - multiple defects are most likely when infection occurs in the first 16 weeks
What are the features of congenital rubella
Eye defects e.g. cataracts
Hearing impairment
Cardiac abnormalities e.g. patent ductus arteriosus and pulmonary artery stenosis
CNS defects e.g. microencephaly, mental and psychomotor retardation, progressive panencephalitis
IUGR
Autism
Endocrine abnormalities e.g. diabetes mellitus, thyroid dysfunction
What investigations should be done for rubella in pregnancy
Oral fluid sample or throat swab for viral culture
Rubella-specific IgM serum antibody for capture ELISA
US: Normal OR
FGR
Microphthalmia
Hepatosplenomegaly
Cardiac defects
What is the management for rubella in pregnancy
Notify the local health protection team (HPT) as it is a notifiable disease
Symptomatic relief: paracetamol, fluids, isolate for 5 days
How is CMV transmitted
1st and 2nd trimester vertical transmission 40% and foetal damage in 10%
3rd trimester vertical transmission 80%
What are the features of congenital CMV
Mortality (6%)
Prematurity
Petechiae, thrombocytopenia, haemolysis
Hepatosplenomegaly
Conjugated hyperbilirubinaemia/jaundice
Microcephaly, hypotonia, seizures
Intracranial calcifications (periventricular)
Long term:
- Psychomotor delay
- Sensorineural hearing loss
- Ocular abnormalities (Chorioretinitis → cataracts)
What are the features of congenital HSV
SEM disease
CNS ± SEM disease
Disseminated disease
Chorioretinitis → cataracts
Vesicular lesions [SKIN, EYES, MOUTH]
CNS signs
Disseminated infection signs
Microcephaly, microphthalmia, LBW
What is the management for HSV in pregnancy
<28w first genital herpes: start antiviral medication from 36w until birth, vaginal delivery allowed
>28w first genital herpes: continue antivirals until baby is born, may require ELCS
Recurrent genital infection → can deliver vaginally
Treatment: IV Aciclovir
What are the clinical features of congenital parvovirus B19 infection
Severe haemolytic anaemia → heart failure → oedema → Hydrops fetalis
Thrombocytopenia → petechial rash
What is the management for congenital Parvovirus B19 infection
FBS and intrauterine blood transfusion if severe foetal anaemia and hydrops in USS.
Risk of 1% foetal loss due to this procedure.
What are the features of congenital varicella
Chorioretinitis → cataracts
Microcephaly
Limb hypoplasia
IUGR
Cutaneous scarring
What is the management for congenital varicella
Aciclovir
What are the features of congenital HIV
Congenital immunodeficiency
Recurrent infections
Presents at 6m – diarrhoea, failure to thrive, fevers, lymphadenopathy, etc.
What is group B streptococcus
Gram positive streptococcus characterised by presence of Group B Lancefield antigen – streptococcus agalactiae
Gram +ve cocci in chains
What are the risk factors for GBS infection
GBS in a previous baby
Prematurity
Rupture of membranes >24 hours before delivery
Pyrexia during labour
Positive test for GBS in the mother
Mother diagnosed with a UTI found to be GBS during pregnancy
What are the symptoms of GBS infection
Often asymptomatic and found incidentally
UTI: frequency, nocturia, dysuria
Chorioamnionitis
Endometritis
What investigations should be done for GBS
Bedside: high vaginal swab, urine dip and MC&S, rectal swab
Bloods: FBC, CRP, U&Es, G&S, Blood cultures, ABG/VBG, coagulation screen, HIV screen
Other: CTG
What is the screening procedure for GBS in pregnancy
Universal screening is not offered and maternal request is not indication
Previous GBS → intrapartum antibiotic prophylaxis (IAP) OR testing in late pregnancy
Swab for GBS 35-37 weeks or 3-5 weeks prior to delivery date
What are the indications for GBS prophylaxis
Intrapartum fever
Prolonged rupture of membranes >18 hours
Prematurity <37 weeks
Previous infant with GBS
GBS bacteriuria
