Intrapartum Infections

Question 1

Chickenpox is caused by

Answer 1

primary infection with varicella-zoster virus

Question 2

Shingles is caused by

Answer 2

the reactivation of dormant virus in dorsal root ganglion

Question 3

In VSV infection in pregnancy, there is a risk to

Answer 3

both the mother and also the fetus, a syndrome now termed fetal varicella syndrome

Question 4

Chickenpox exposure, Risks to the mother?

Answer 4

5 times greater risk of pneumonitis

Question 5

Fetal varicella syndrome (FVS)

risk?

Answer 5

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

Question 6

features of FVS

Answer 6

skin scarring, eye defects (microphthalmia), limb hypoplasia, microcephaly and learning disabilities

shingles in infancy:
severe neonatal varicella

Question 7

severe neonatal varicella occurs when?

Answer 7

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

Question 8

shingles in infancy risks

Answer 8

1-2% risk if maternal exposure in the second or third trimester

Question 9

Management of chickenpox exposure in pregnancy,

if there is any doubt about the mother previously having chickenpox do what

Answer 9

maternal blood should be urgently checked for varicella antibodies

Question 10

if the pregnant woman <= 20 weeks gestation is not immune to varicella she should be given

Answer 10

varicella-zoster immunoglobulin (VZIG) as soon as possible

RCOG and Greenbook guidelines suggest VZIG is effective up to 10 days post exposure

Question 11

if the pregnant woman > 20 weeks gestation is not immune to varicella then what should be given

Answer 11

either VZIG or antivirals (aciclovir or valaciclovir) should be given days 7 to 14 after exposure

Question 12

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’

Answer 12

true

Question 13

Management of chickenpox in pregnancy

Answer 13

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’

Question 14

Group B Streptococcus (GBS) is the most common cause of early-onset severe infection in the neonatal period

Answer 14

true

Question 15

It is thought around ?% of mothers have GBS present in their bowel flora and may therefore be thought of as ‘carriers’ of GBS

Answer 15

20-40%

Question 16

Infants may be exposed to maternal GBS during labour and subsequently develop potentially serious infections.

Answer 16

true

Question 17

Risk factors for Group B Streptococcus (GBS) infection:

Answer 17

prematurity
prolonged rupture of the membranes
previous sibling GBS infection
maternal pyrexia e.g. secondary to chorioamnionitis

Question 18

Mx Group B Streptococcus (GBS) infection

Answer 18

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

Question 19

? is the antibiotic of choice for GBS prophylaxis

Answer 19

benzylpenicillin

Question 20

universal screening for GBS should not be offered to all women

Answer 20

true

Question 21

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?

Answer 21

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

Question 22

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.

Answer 22

true

Question 23

The aim of treating HIV positive women during pregnancy is

Answer 23

to minimise harm to both the mother and fetus, and to reduce the chance of vertical transmission.

Question 24

Factors which reduce vertical transmission

Answer 24

maternal antiretroviral therapy
mode of delivery (caesarean section)
neonatal antiretroviral therapy
infant feeding (bottle feeding)

Question 25

NICE guidelines recommend offering HIV screening to all pregnant women

Answer 25

true

Question 26

Factors which reduce vertical transmission reduce rates from 25-30% to ?%?

Answer 26

2%

Question 27

All HIV+ve pregnant women should be offered antiretroviral therapy regardless of whether they were taking it previously

Answer 27

true

Question 28

Mode of delivery HIV pts

Answer 28

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

Question 29

Neonatal antiretroviral therapy

Answer 29

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.

Question 30

Infant feeding HIV?

Answer 30

all women should be advised not to breast feed

Question 31

Rubella, also known as German measles, is a viral infection caused by

Answer 31

togavirus

Question 32

If rubella contracted during pregnancy there is a risk of

Answer 32

congenital rubella syndrome

Question 33

rubella | infectivity and incubation

Answer 33

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.

Question 34

risks of rubella?

Answer 34

in first 8-10 weeks risk of damage to fetus is as high as 90% damage is rare after 16 weeks

Question 35

Features of congenital rubella syndrome

Answer 35

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

Question 36

Diagnosis rubella?

Answer 36

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

Question 37

Management rubella immunity antenatally?

Answer 37

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

Question 38

all pregnant women are offered screening for hepatitis ?

Answer 38

B

Question 39

babies born to mothers who are chronically infected with hepatitis B or to mothers who've had acute hepatitis B during pregnancy should receive

Answer 39

a complete course of vaccination + hepatitis B immunoglobulin

Question 40

hepatitis B - caesarean section reduces vertical transmission rates

Answer 40

false | there is little evidence to suggest caesarean section reduces vertical transmission rates

Question 41

hepatitis B & HIV can be transmitted via breastfeeding

Answer 41

false | hepatitis B cannot be transmitted via breastfeeding (in contrast to HIV)

Question 42

Chorioamnionitis can affect up to ?% of all pregnancies

Answer 42

5%

Question 43

Chorioamnionitis is a medical emergency

Answer 43

True | threatening condition to both mother and foetus and is therefore considered a medical emergency

Question 44

Chorioamnionitis is usually the result of

Answer 44

ascending bacterial infection of the amniotic fluid / membranes / placenta

Question 45

Chorioamnionitis mx

Answer 45

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.