Intrapartum Infections Flashcards
Chickenpox is caused by
primary infection with varicella-zoster virus
Shingles is caused by
the reactivation of dormant virus in dorsal root ganglion
In VSV infection in pregnancy, there is a risk to
both the mother and also the fetus, a syndrome now termed fetal varicella syndrome
Chickenpox exposure, Risks to the mother?
5 times greater risk of pneumonitis
Fetal varicella syndrome (FVS)
risk?
risk of FVS following maternal varicella exposure is around 1% if occurs before 20 weeks gestation
studies have shown a very small number of cases occurring between 20-28 weeks gestation and none following 28 weeks
features of FVS
skin scarring, eye defects (microphthalmia), limb hypoplasia, microcephaly and learning disabilities
shingles in infancy:
severe neonatal varicella
severe neonatal varicella occurs when?
if the mother develops rash between 5 days before and 2 days after birth there is a risk of neonatal varicella, which may be fatal to the newborn child in around 20% of cases
shingles in infancy risks
1-2% risk if maternal exposure in the second or third trimester
Management of chickenpox exposure in pregnancy,
if there is any doubt about the mother previously having chickenpox do what
maternal blood should be urgently checked for varicella antibodies
if the pregnant woman <= 20 weeks gestation is not immune to varicella she should be given
varicella-zoster immunoglobulin (VZIG) as soon as possible
RCOG and Greenbook guidelines suggest VZIG is effective up to 10 days post exposure
if the pregnant woman > 20 weeks gestation is not immune to varicella then what should be given
either VZIG or antivirals (aciclovir or valaciclovir) should be given days 7 to 14 after exposure
PEP for chicken pox
The decision on choice of PEP for women exposed from 20 weeks of pregnancy should take into account patient and health professional preference as well as the ability to offer and provide PEP in a timely manner’
true
Management of chickenpox in pregnancy
if a pregnant woman develops chickenpox in pregnancy then specialist advice should be sought
there is an increased risk of serious chickenpox infection (i.e. maternal risk) and fetal varicella risk (i.e. fetal risk) balanced against theoretical concerns about the safety of aciclovir in pregnancy
consensus guidelines (Health Protection Authority and RCOG) suggest oral aciclovir should be given if the pregnant women is ≥ 20 weeks and she presents within 24 hours of onset of the rash
if the woman is < 20 weeks the aciclovir should be ‘considered with caution’
Group B Streptococcus (GBS) is the most common cause of early-onset severe infection in the neonatal period
true
It is thought around ?% of mothers have GBS present in their bowel flora and may therefore be thought of as ‘carriers’ of GBS
20-40%
Infants may be exposed to maternal GBS during labour and subsequently develop potentially serious infections.
true
Risk factors for Group B Streptococcus (GBS) infection:
prematurity
prolonged rupture of the membranes
previous sibling GBS infection
maternal pyrexia e.g. secondary to chorioamnionitis
Mx Group B Streptococcus (GBS) infection
If women are to have swabs for GBS this should be offered at 35-37 weeks or 3-5 weeks prior to the anticipated delivery date
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
? is the antibiotic of choice for GBS prophylaxis
benzylpenicillin
universal screening for GBS should not be offered to all women
true
The guidelines also state a maternal request is not an indication for screening
women who’ve had GBS detected in a previous pregnancy
What should you do with these women?
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
With the increased incidence of HIV infection amongst the heterosexual population there are an increasing number of HIV positive women giving birth in the UK.
true
The aim of treating HIV positive women during pregnancy is
to minimise harm to both the mother and fetus, and to reduce the chance of vertical transmission.
Factors which reduce vertical transmission
maternal antiretroviral therapy
mode of delivery (caesarean section)
neonatal antiretroviral therapy
infant feeding (bottle feeding)
NICE guidelines recommend offering HIV screening to all pregnant women
true
Factors which reduce vertical transmission reduce rates from 25-30% to ?%?
2%
All HIV+ve pregnant women should be offered antiretroviral therapy regardless of whether they were taking it previously
true
Mode of delivery HIV pts
vaginal delivery is recommended if viral load is less than 50 copies/ml at 36 weeks, otherwise caesarian section is recommended
a zidovudine infusion should be started four hours before beginning the caesarean section
Neonatal antiretroviral therapy
zidovudine is usually administered orally to the neonate if maternal viral load is <50 copies/ml. Otherwise triple ART should be used. Therapy should be continued for 4-6 weeks.
Infant feeding HIV?
all women should be advised not to breast feed
Rubella, also known as German measles, is a viral infection caused by
togavirus
If rubella contracted during pregnancy there is a risk of
congenital rubella syndrome
rubella
infectivity and incubation
incubation period is 14-21 days and individuals are infectious from 7 days before symptoms appear to 4 days after the onset of the rash.
risks of rubella?
in first 8-10 weeks risk of damage to fetus is as high as 90%
damage is rare after 16 weeks
Features of congenital rubella syndrome
sensorineural deafness
congenital cataracts, ‘salt and pepper’ chorioretinitis, microphthalmia
growth retardation, cerebral palsy
hepatosplenomegaly
congenital heart disease (e.g. patent ductus arteriosus)
purpuric skin lesions
Diagnosis rubella?
suspected cases should be discussed immediately with the local Health Protection Unit (HPU) as type/timing of investigations may vary
IgM antibodies are raised in women recently exposed to the virus
it should be noted that it is very difficult to distinguish rubella from parvovirus B19 clinically. It is therefore important to also check parvovirus B19 serology as there is a 30% risk of transplacental infection, with a 5-10% risk of fetal loss
Management rubella immunity antenatally?
suspected cases of rubella in pregnancy should be discussed with the local Health Protection Unit
since 2016, rubella immunity is no longer routinely checked at the booking visit
if a woman is however tested at any point and no immunity is demonstrated they should be advised to keep away from people who might have rubella
non-immune mothers should be offered the MMR vaccination in the post-natal period
MMR vaccines should not be administered to women known to be pregnant or attempting to become pregnant
all pregnant women are offered screening for hepatitis ?
B
babies born to mothers who are chronically infected with hepatitis B or to mothers who’ve had acute hepatitis B during pregnancy should receive
a complete course of vaccination + hepatitis B immunoglobulin
hepatitis B - caesarean section reduces vertical transmission rates
false
there is little evidence to suggest caesarean section reduces vertical transmission rates
hepatitis B & HIV can be transmitted via breastfeeding
false
hepatitis B cannot be transmitted via breastfeeding (in contrast to HIV)
Chorioamnionitis can affect up to ?% of all pregnancies
5%
Chorioamnionitis is a medical emergency
True
threatening condition to both mother and foetus and is therefore considered a medical emergency
Chorioamnionitis is usually the result of
ascending bacterial infection of the amniotic fluid / membranes / placenta
Chorioamnionitis mx
Prompt delivery of the foetus (via cesarean section if necessary) and administration of intravenous antibiotics is widely considered the mainstay of initial treatment for this condition.
