Infections in Pregnancy Flashcards
Why are infections particularly important in pregnancy?
Maternal illness - may be wore as with varicella
Maternal complications - as with pre-eclampsia in HIV +ve women, may be more common
Preterm labour - associated with infections
Vertical transmissions - innocuous infections can cause miscarriage, be teratogenic or damage developing organs
Neurological damage - more common in the presence of bacterial infection in both preterm and term babies
Abx - usage in pregnancy is occasionally limited by adverse effects to the foetus
Describe the pathology of CMV?
CMV is a herpesvirus - transmitted by personal contact
What is the impact of CMV in pregnancy?
common cause of childhood handicap or deafness
Fetal growth restriction Microcephaly Hearing loss Vision loss Learning disability Seizures
How is CMV diagnosed?
USS abnormalities are evident in 20% (intracranial or hepatic calcification)
CMV IgM remains +ve fora long time after infection and could predate the pregnancy, so can do IgM titters
IgG avidity will be low with recent infection
if maternal infection is confirmed, amniocentesis at least 6 weeks after maternal infection will confirm or refute vertical transmission
What is the management of maternal CMV?
USS
no prenatal treatment
termination may be offered
Routine screening is not advised and no vaccine available
What is the pathology of herpes simplex infection?
Type 2 DNA virus causes genital herpes
<5% women have history of prior infection, but many have antibodies
What is the foetal/neonatal effect of herpes simplex
HSV is not teratogenic and neonatal infection is rare, but has a high mortality
Vertical transmission occurs at vaginal delivery, particularly if vesicles are present. Most likely to follow recent primary maternal infection as the foetus will not have passive immunity from maternal antibodies
How is herpes simplex diagnosed?
clinically
swabs are of little use in pregnancy
What is the management of maternal herpes simplex?
referral to GUM - C-section is recommended for those delivering within 6 weeks of primary attack and those with genital lesions - risk is very low in recurrent herpes who have vesicles at time of labour, so C-section not recommended
Daily acyclovir in late pregnancy may reduce the frequency of recurrences at term - exposed neonates are given aciclovir
What are the risks of VZV in pregnancy?
More severe cases in the mother, such as varicella pneumonitis, hepatitis or encephalitis
Fetal varicella syndrome
Severe neonatal varicella infection (if infected around delivery)
What are the foetal/neonatal effects of herpes zoster?
Fetal growth restriction
Microcephaly, hydrocephalus and learning disability
Scars and significant skin changes located in specific dermatomes
Limb hypoplasia (underdeveloped limbs)
Cataracts and inflammation in the eye (chorioretinitis)
What is the management of maternal herpes zoster?
If exposed to chickenpox:
women are tested for immunity and immunoglobulin given within 10 days if non-immune or acivlovir given if infection occurs
in late pregnancy, if delivery is 5 days after or 2 days before maternal symptoms then neonate are given immunoglobulins and acivloir if infection occurs, vaccination is possible
describe the pathology of rubella
congenital rubella syndrome is caused by maternal infection with the rubella virus during the first 20 weeks of pregnancy. The risk is highest before ten weeks gestation.
What are the foetal/neonatal effects of rubella?
Congenital deafness
Congenital cataracts
Congenital heart disease (PDA and pulmonary stenosis)
Learning disability
What is the management of rubella?
Women planning to become pregnant should ensure they have had the MMR vaccine. When in doubt, they can be tested for rubella immunity. If they do not have antibodies to rubella, they can be vaccinated with two doses of the MMR, three months apart.
Pregnant women should not receive the MMR vaccination, as this is a live vaccine. Non-immune women should be offered the vaccine after giving birth.
if non-immune women develops rubella <16 weeks then termination is offered
What is the pathology of parvovirus?
Parvovirus B19 infects 0.25% of pregnant women, but 50% are immune
What is the appearance of parvovirus?
‘slapped cheek appearance’
A few days later a reticular mildly erythematous rash affecting the trunk and limbs appears, which can be raised and itchy.
may have arthralgia or be asymptomatic - infection usually from children
What are the foetal/neonatal effects of parvovirus?
Miscarriage or fetal death
Severe fetal anaemia
Hydrops fetalis (fetal heart failure)
Maternal pre-eclampsia-like syndrome
How is diagnosis of parvovirus done?
IgM to parvovirus, which tests for acute infection within the past four weeks IgG to parvovirus, which tests for long term immunity to the virus after a previous infection Rubella antibodies (as a differential diagnosis)
What is the management of of parvovirus?
Treatment is supportive. Women with parvovirus B19 infection need a referral to fetal medicine to monitor for complications and malformations
What is the pathology of Hepatitis B?
Caused by small DNA virus and transmitted by blood products or sexual activity - infection resolves in 90% adults, but persists in 10%
What are the fetal/neonatal effects of hepatitis B?
Vertical transmission occurs in delivery - 90% of infected neonates become chronic carriers, compared to 10% of adults
What is the management of hepatitis B?
Screening at booking
To reduce the risk of the baby contracting hepatitis B, at birth (within 24 hours) neonates with hepatitis B positive mothers should be given both:
Hepatitis B vaccine
Hepatitis B immunoglobulin infusion
Infants are given an additional hepatitis B vaccine at 1 and 12 months of age. They will also receive the hepatitis B vaccine as part of the normal 6 in 1 vaccine given to all infants aged 8, 12 and 16 weeks. They are tested for the HBsAg at 1 year to see if they have contracted hepatitis B.
What % of pregnant women in the UK are infected with Hepatitis C?
0.5%
Worldwide incidence of 3% and 30% in HIV +ve
What are the main risk factors of Hepatitis C?
Drug abuse and sexual transmission
What is the effect of hepatitis C infection?
Chronic hepatitis (80%) most pregnant women are asymptomatic
In What % of women does vertical transmission of Hepatitis C occur?
3-5%
higher if large viral load or co-exisiting HIV
What is the management of hepatitis C?
Elective C-section, avoidance of breast feeding and administration of immunoglobulin
screening - restricted to high risk group
What are the maternal effects of HIV?
incidence of pre-eclampsia is greater and may be increased by anti-retroviral therapy
Gestational diabetes may also be more common
What are the neonatal effects of HIV?
stillbirth, pre-eclampsia, growth restriction and prematurity are more common
vertical transmission is mostly beyond 36 weeks, intrapartum or during breastfeeding
25% of HIV infected neonates will develop AIDS in 1 year and 40% in 5 years
What is the management of HIV?
Screening - universial
+ve women should have regular CD4 and viral load tests. Prophylaxis against PCP if CD4 count is low
drug toxicity is monitored with liver and renal function, haemoglobin and blood glucose testing
HAART reduces viraemia and maternal disease pregression and should be continued throughout pregnancy and delivery with the neonate treated for the first 6 weeks.
If woman is not receiving pre-pregnancy treatment then it is started at 28 weeks - C-section is recommended if viral load is above 50 copies/ml and there is coexistent hepatitis C infection
breastfeeding avoided
What are the maternal effects of influenza?
pandemic influenza A H1N1 (swine flu) particularly affects pregnant women - especially those with comorbitiy include obesity
What is the management of maternal influenza?
If symptoms are present then oseltamivir should be prescribed and admission considered if there is respiratory symptoms - seasonal, yearly vaccination with an inactivated vaccine is strongly recommended for pregnant women at any gestation
What is the effect of the Zika virus?
Microcephaly
Fetal growth restriction
Other intracranial abnormalities, such as ventriculomegaly and cerebellar atrophy
How is Zika virus transmitted?
spread by host Aedes mosquitos in areas of the world where the virus is prevalent. It can also be spread by sex with someone infected with the virus.
How can Zika virus be detected?
viral PCR and antibodies to the Zika virus. Women with a positive result should be referred to fetal medicine for close monitoring of the pregnancy.
What does Group A strep tend to cause?
Puerperal sepsis - most common bacterium associated with maternal death
What % of people carry group A strep?
5-30%
What is the most common symptom of GAS?
sore throat
How does maternal infection of GAS occur during pregnancy?
maternal hand to perineal contamination
What are the effects of GAS?
Can get chorioamnionitis - infection of chorioamniotic membranes and amniotic fluid
What is the management of maternal GAS?
Early recognition, cultures and high dose antibiotics + ICU is required
What is the pathology of GBS?
bacterium streptococcus agalactiae is carried without symptoms by 25% pregnant women
What are the neonatal effects of GBS?
foetus can be infected during labour or after the membrane ruptures - most common with preterm labour, if labour is prolonged or there is maternal fever - early onset neonatal GBS sepsis - causes severe illness
What is the management of GBS?
universal screening for GBS should not be offered to all women
women who’ve had GBS detected in a previous pregnancy should be informed that their risk of maternal GBS carriage in this pregnancy is 50%.
They should be offered intrapartum antibiotic prophylaxis (IAP) OR testing in late pregnancy and then antibiotics if still positive
IAP should be offered to women with a previous baby with early- or late-onset GBS disease
IAP should be offered to women in preterm labour regardless of their GBS status
women with a pyrexia during labour (>38ºC) should also be given IAP
benzylpenicillin is the antibiotic of choice for GBS prophylaxis
What is the cause of syphilis?
STI due to treponema pallidum
What does syphilis cause in pregnancy?
Miscarriage, severe congenital disease or still birth
What is the management of syphilis?
Screening tests
Prompt treatment with benzylpenicillin - safe and will prevent but not reverse fetal damage
What is the pathology of toxoplasmosis?
due to the protozoan parasite toxoplasma gondii - follows contact with cat faeces or soil or eating infected meat.
In UK, 20% of adults have antibodies - infection in pregnancy occurs in 0.2% of women in the UK
What are the foetal effects of toxoplasmosis?
Intracranial calcification
Hydrocephalus
Chorioretinitis (inflammation of the choroid and retina in the eye)
How is diagnosis of toxoplasmosis done?
USS - may show hydrocephalus, but maternal infection is usually diagnosed due to exposure or anxiety - vertical transmission is diagnosed or excluded via amniocentesis after 20 weeks
How is toxoplasmosis managed?
Health education reduces maternal risk - spiramycin is started as soon as woman is diagnosed - additional combination therapy of pyrimethamine and sulfadiazine with folinic acid is given if vertical transmission confirmed
What is the cause of listeriosis?
listeria monocytogenes - gram +ve bacillus
Infection can follow consumption of pale, soft cheeses and prepacked meals
What does listeriosis cause?
miscarriage or fetal death. It can also cause severe neonatal infection.
How is diagnosis of listeriosis done?
Blood cultures - prevention is key
What Is the cause of chlamydia?
Chlamydia trachomatis - occurs in 5% of pregnant women
What is the cause of gonorrhoea?
Neisseria gonorrhoea - occurs in 0.1% pregnant women
What are the results of chlamydia / gonorrhoea during pregnancy?
most = asymptomatic
best known as causes of PID and sub fertility - both have an association with preterm labour and neonatal conjunctivitis
What is the treatment of chlamydia?
Azithromycin or erythromycin
tetracyclines cause foetal tooth discolouration
What is the treatment of maternal gonorrhoea?
Cephalosporins
What is the cause of bacterial vaginosis?
Common overgrowth of normal vaginal lactobacilli by anaerobes - such as Gardneralla vaginalis and mycoplasma hominid
What are the symptoms of bacterial vaginosis?
Can be asymptomatic or cause offensive vaginal discharge
What are the effects of bacterial vaginosis?
Preterm labour and late miscarriage
What is the treatment of bacterial vaginosis?
Oral clindamycin - reduces the risk of preterm birth if used <20 weeks
