Infections in pregnancy

Question 1

What complications can the cytomegalovirus cause?

Answer 1

If the mother is infected, there is 40% chance of transmission.
In those who are symptomatic from birth (10%), they have intrauterine growth restriction (IUGR), pneumonia and thrombocytopenia. Most of these will go on to develop severe neurological sequelae such as hearing, visual and mental impairment, or will die.
Of those who are asymptomatic, they are at risk of deafness (15%).

Question 2

How do you diagnose and manage maternal and neonatal CMV?

Answer 2

Diagnose - mother can be tested, although IgM remains positive long after infection; recent infection is shown by titres rising and low IgG.
If recent infection is confirmed, amniocentesis at least 6 weeks after maternal infection will confirm or refute vertical transmission.
Management: most neonates are not seriously affected; close surveillance for US abnormality may determine those at most risk for severe sequelae –> termination may be offered as there is no prenatal treatment.

Question 3

What type of virus is cytomegalovirus?

Answer 3

Herpes virus

Question 4

When is transmission of herpes simplex virus to a fetus most common?

Answer 4

Vertical transmission at vaginal delivery following a recent primary maternal infection (40%), because the foetus will not have passive immunity from the mother.

Question 5

How common is neonatal transmission of herpes and what are the outcomes?

Answer 5

Very rare. High mortality.

Question 6

How do you manage maternal herpes? Does it matter if it is a new or latent infection?

Answer 6

C-section recommended for those delivering in 6 weeks of a primary attack and for those with genital lesions from primary infection at the time of delivery.
Risk is low in women with recurrent herpes who have vesicles present because the foetus has passive immunity, and so C-section is not recommended.

Question 7

What is used to treat herpes simplex in mother and child?

Answer 7

Aciclovir

Question 8

What are the maternal and foetal complications of herpes zoster (chicken pox)?
When is the foetus most likely to be infected?

Answer 8

Maternal - can cause severe maternal illness.
Neonatal - teratogenicity is a rare (1-2%) consequence of early pregnancy infection.
If maternal infection is in the 4 weeks preceding delivery it can cause severe neonatal infection. This is most common if delivery occurs 5 days after or 2 days before maternal symptoms.

Question 9

What is the management of herpes zoster in pregnancy?

Answer 9

Immunoglobulin is used to prevent and oral aciclovir is used to treat infection. Pregnant women are tested for immunity after exposure to the virus.
Neonates are given immunoglobulins if delivery was in the high risk time (5 days after or 2 days before maternal symptoms).

Question 10

What are the teratogenic infections?

Answer 10

Cytomegalovirus
Toxoplasmosis
Rubella 
Syphilis 
Herpes zoster (rare)

Question 11

Why is congenital rubella rare in UK?

Answer 11

National vaccination.

Question 12

What does rubella infection cause in early pregnancy?

Answer 12

Deafness, cardiac disease, eye problems and mental retardation.

Question 13

What are non-immune women who develop rubella before 16 weeks gestation offered?

Answer 13

Termination of pregnancy.

Question 14

What is parvovirus?

Answer 14

Slap cheek - most infections come from children.

Question 15

What are the complications of maternal parvovirus for the foetus?

Answer 15

Anaemia - foetal death occurs in 10%.

This can cause hydrops in foetal (detected on US).

Question 16

How are severe complications of foetal parvovirus treated?

Answer 16

In severe forms of anaemia, an in utero transfusion is given.

Question 17

What proportion of maternal and foetal carriers of hepatitis B become chronic?

Answer 17

10% of adults.

90% of neonates.

Question 18

How are hepatitis B positive women and their foetus’ treated?

Answer 18

Mother - Given neonatal immunisation to reduce risk of infection. Also treated with antiviral agents from 32 weeks.
Neonate - passive immunisation given postnatally to the neonate.

Question 19

With hepatitis C, does C-section, no breastfeeding and administration of immune globulin reduce the vertical transmission to the neonate?

Answer 19

no.

Question 20

What pregnancy complications are more common in those infected with HIV?

Answer 20

Pre-eclampsia and possibly gestational diabetes.

Stillbirth, growth restriction and prematurity are more common.

Question 21

What serum levels can be detected and show an increased risk of transmission to the neonate?

Answer 21

Low CD4 count and high viral load.

Question 22

What is the best strategy to prevent HIV vertical transmission?

Answer 22

Highly active antiretroviral therapy (HAART), which reduces viraemia and maternal disease progression.
Neonatal antiretroviral therapy for 6 weeks.
C-section where viral load is high.
Breast feeding is avoided.

Question 23

What is advised about breast feeding in UNDER-RESOURCED countries?

Answer 23

Breast feed for 6 months with prophylaxis (zidovudine) - formula only slightly reduces the risk, but there is higher mortality where breast feeding is not used.

Question 24

What are the effects of influenza on pregnancy?

Answer 24

12% of maternal deaths were related to influenza during pandemics.
No foetal effects.
The vaccination is recommended to all pregnant women, regardless of gestation.

Question 25

How are pregnant women infected with the ZIKA virus? How is it prevented?

Answer 25

Mosquitos (active during daytime).

Protection using repellants and not travelling to countries with current endemics.

Question 26

What are the effects of ZIKA virus on mother and foetus?

Answer 26

Mother - rash and fever. Potentially Guillian-Barre.
Foetus - CNS abnormalities (microcephaly, intracranial calcification, ventriculomegaly) –> scanned to check and if abnormality is present, termination is offered.

Question 27

What bacterium is the most common cause of maternal death and sepsis?

Answer 27

Group A streptococcus (streptococcus pyogenes).

Question 28

What causes streptococcal group A infection in a foetus and what is the consequence?

Answer 28

From maternal hand to perineal contamination.
Chorioamnionitis with abdominal pain, diarrhoea and severe sepsis may occur. The infected foetus often dies in utero and labour ensues.

Question 29

What preventative measures are there when a pregnant woman is infected with group A streptococcus?

Answer 29

Cultures and high dose antibiotics +/- intensive care in severe cases is required.

Question 30

How common is strep B in pregnancy and is it passed on? If so, how?

Answer 30

It is very common - 25% of women are carriers.
The foetus can be infected during labour if the membranes have ruptured. This is most common with preterm labours, if labour is prolonged of there is maternal fever.

Question 31

What is the consequence of group B streptococcus in infants?

Answer 31

6% mortality in term infants. 18% mortality in preterm infants.

Question 32

How can vertical transmission of group B streptococcus prevented?

Answer 32

High-dose IV penicillin throughout labour. In UK it is only high-risk pregnancies that are treated - there is no screening.

Question 33

What are the effects of active syphilis in pregnancy and what is the treatment?

Answer 33

Active syphilis in pregnancy causes miscarriages, severe congenital disease or stillbirth.
Prompt treatment with benzylpenicillin is safe and will prevent foetal damage but it will not reverse damage which has already occurred.

Question 34

How is toxoplasmosis infected by pregnant women?

Answer 34

Through cat faeces or soil, or eating infected meat.

Question 35

How common is toxoplasmosis in pregnancy and what is the consequence of infection?

Answer 35

Very rare (0.2%).
Consequences - mental handicap, convulsions, spasticities and visual impairment. Vertical transmission to the foetus is possible later on in pregnancy and can be confirmed after 20 weeks by amniocentesis.

Question 36

What treatment is given for toxoplasmosis?

Answer 36

Spiramycin is started as soon as diagnosed.
If vertical transmission is confirmed, additional combination therapy of pyrimethamine and sulfadiazine with folinic acid is used.

Question 37

How is Listeriosis caught? What are its complications in pregnancy?

Answer 37

By consuming pates, soft cheeses and pre-packed meals.

Potentially fatal infection of the foetus may follow.

Question 38

What is diagnosis of TB in late pregnancy associated with?

Answer 38

Prematurity and IUGR.

Question 39

What are the complications of malaria in pregnancy?

Answer 39

Maternal anaemia, IUGR and stillbirth.

Question 40

What are the consequences of chlamydia and gonorrhoea maternal infection? How are they treated?

Answer 40

Preterm birth.
Chlamydia - azithromycin and erythromycin
Gonorrhoea - cephalosporins (resistance to penicillin is common).

Question 41

What does bacterial vaginitis increase the risk of in pregnancy?

Answer 41

Preterm labour and late miscarriage are more common. Treatment reduces the risk of preterm birth if used before 20 weeks.