27. Pregnancy and Infection Flashcards
What are the 5 commonest causes accounting for 75% of maternal deaths?
What is different about infection in pregnancy?
List some infections that are hamful to mum, foetus and both.
Severe bleeding, infections (usually after birth), hypertension during pregnancy (PE and E), delivery complications, unsafe abortion.
Relative immunosupression, physiological changes in mum, 1st trimester = most development so infection worse for baby,
Mum: influenza. Foetus: TORCHES (imp congenital: toxoplasmosis, other, rubella, CMV, herpes, HIV, hep), syphilis, HSV, parvovirus B19. Both: Hep A/E/B/C, VZV, HIV.
What are the 2 ways of diagnosing infection in pregnancy?
How is CMV transmitted and if infected during pregnancy, why is timing important?
How is congenital CMV diagnosed and what are some symptoms?
1) Serology: look for IgM (formed in 1st few weeks of acute infection) and IgG (longer exposure -> some immunity). 2) PCR: for DNA/RNA of pathogen.
Saliva, blood/blood products, sex, organ transplants, via mum. Primary infection more likely to cause congenital CMV. Congential CMV more likely in 1st trimester.
Maternal serology (CMV IgG and IgM), neonatal urine/saliva for CMV DNA PCR. Symptoms: IUGR, hepatosplenomegaly, microcephaly, sensorineural deafness (commonest causes, 10% of asymptommatic kids develop it in first 5-7yrs).
How is VZV transmitted, and how do the risks associated with infection depend on timing?
How is VZV diagnosed and managed?
What is congenital varicella syndrome?
Droplet/airbourne, extremely infectious, 80-90% UK adults immune, mum = worse if later, foetus = more complicated.
Diagnosis: clinical syndrome (characteristic rash), swab of vesicle fluid (viral PCR), maternal serology. Management: prevention (post exposure VZ immunoglobulin, pre exposure vaccination), treat with (val)acyclovir (safe during pregnancy).
Baby gets chicken pox in utero -> uncontrolled viral replication and limb scarring. Skin lesions (73%) leading to limb hypoplasia, CNS (62%) leading to micro/hydrocephaly and neurodevelopmental delay, cataracts, GI/genitourinary/cardiac abnormalites, miscarriage. [Pic]
What is this condition?
Chicken pox
What is this condition?
Shingles: reactivation of VZV later in life, usually in one dermatome only b/c VZV forms latent infection in one of the dorsal root ganglia. R = opthalmis VZV, serious.
What is neonatal varicella?
What diseases is HSV associated with?
How do neonates acquire HSV? How is it diagnosed and managed?
Mother has VZV around time of delivery, most severe if 5 days before to 2 days after delivery, can be fatal, neonate should get VZIG and acyclovir. [Pic]
Genital or oral ulceration, oesophagitis, CNS infection - encephalitis. V common - >90% adults have HSV 1 Abs by 40, HSV 2 seroprevalence relalated to sexual activity. >80% 10 HSV infection asymptomatic.
Most acquire it perinatally. Nearly all manifest disease. Diagnosis: Clinical, HSV DNA PCR neonate blood/vesicle swab/maternal vesicle swab. Management: Mortality (untreated) 65% reduced to 25% with acyclovir.
What is this condition?
Neonatal HSV
What is rubella? How is it diagnosed?
How is rubella risk to pregnancy dependant on gestational age?
What problems does congenital rubella cause for the foetus?
What kind of vaccine is MMR?
German measles. Uncommon, <95% have Abs to it (due to MMR vaccine), rash, lymphadenopathy, arthralgia. Diagnosis: serology/oral fluid PCR. No treatment.
Less risk the older the foetus (minimal by 16/40 - 20/40), but in 1st trimester = 90%.
Microcephaly, heart disease, petechiae and purpura, cataracts, glaucoma and other eye anomalies. Baby dependant for life.
Live attenuated. 2 doses = lifelong protection.
What is the cellular target of parvovirus B19? How is it diagnosed?
How do the risks of parvovirus to pregnancy depend on the trimester?
How is toxoplasmosis transmitted?
How is congenital toxoplasmosis risk different based on the infection time?
RBCs. Diagnosis: slapped cheek, meternal serology/PCR, foetal ultrasound.
0-20w: 90% foetal loss, 9-20w: 3% hydrops fetalis (oedema in at least 2 fetal compartments e.g. plura, pericardium. Can cause anemia -> heart failure so may need to give intrauterine blood transfusions), >20w: negligible risk.
Due to Toxoplasma gondii, natural host = cat, humans intermediate host via oocyst ingestation (contact with cat feces/infected meat), normally asymptomatic or lymphadenopathy and fever. Infection lifelong.
Risk of congenital disease lowest if infection in 1st trimester, but congenital disease is more severe when it occurs during 1st trimester.
What are the clinical features of congenital toxoplasmosis?
How is it diagnosed and treated?
What is syphilis, and how is it diagnosed?
When is syphillus at the highest risk of transmission in pregnancy? How is it treated?
IUGR, hydrocephalus, cerebral calcification, microcephaly, hepatosplenomegaly.
Diagnosis: maternal serology/amniotic fluid PCR. Treatment: complicated, depends on trimester, spyramicin, sulfadiazine… No vaccine so use avoidance behaviour!
STI due to spirochete Treponema pallidum, common in UK and increasing, diagnosis: clinical syndrome and serology.
1st trimester or peripartum. Can be associated with miscarriage/stillbirth. Tx: penicillin.
What is this condition?
Syphilis.
L = primary syphilis - ulcer.
Top R = secondary syphillis, blistering rash usually on hands and feet
Bottom R = tertiary syphillus = erosions of nasal bone and cartilage, don’t see anymore.
Differentiate between early and late (rare) congenital syphilis.
What antenatal infections are screened for at 12/40?
What are som ethical issues?
Early: 0-2yrs, rash, rhinorrhoea, osteochondritis, perioral fissures, lymphadenopathy, glomeronephritis.
Late: >2yrs, Hutchinson’s teeth, Clutton’s joints, high arched palate, deafness, saddle nose deformity, frontal bossing. [Pic]
Hep B, HIV, syphilis, CMV/toxoplasma/VZV. Plus regular ultrasound to monitor foetal development.
Antenatal screening = early detection of high risk pregnancies. Serology can be hard to interpret. Restrospecitve TORCHES infections may lead to amniocentesis, abortion, or no treatment available..
Termination can be offered >24w only if substantial risk that child born would be seriously handicapped.
