7. Infections in pregnancy Flashcards
Why are infections more prevalent and more dangerous during pregnancy?
The mother is relatively immunosuppressed
There are physiological changes occurring in the mother leaving her more vulnerable
When are infections more likely to cause harm to the foetus/mother?
All of the foetal development is occurring in the first trimester so infections during this time will impact on the foetus
Infections in the third trimester are more harmful to the mother
What are the main infections that occur during pregnancy and how can these be easily remembered?
TORCHES Toxoplasmosis Other Rubella Cytomegalovirus (CMV) Herpes simplex virus (HSV) e.g. HIV, hepatitis
How are infections diagnosed in pregnancy?
Bacterial infection - swab or sample and culture this
Viral infection - serology or Pcr (this is very sensitive and very quick)
What are the different antibodies present in the bloodstream in response to an infection?
IgM is the first antibody produced in response to an infection
IgG is the second
If the patient is IgM positive then they have had a recent, acute infection
If the patient is IgG positive then they have contracted an infection in the past 24-48 hours
How common is cytomegalovirus and what type of virus is this?
When might this occur during pregnancy?
This is a herpes virus and is extremely common
50% of UK adults have had past exposure to this (50% of adults at IgG positive)
This can occur during any time in the pregnancy
Having it in the first trimester is most problematic to the foetus
When is CMV virus most dangerous to the foetus?
If the mother contracts CMV for the first time in the pregnancy then the foetus is more likely to develop congenital CMV
If the mother has had CMV in the past then the risk to the baby is much less
How common is congenital CMV and how is it diagnosed?
0.7% of live births have congenital CMV
Diagnosed via the maternal serology CMV IgG and IgM and also the neonatal urine/saliva
What are the symptoms of congenital CMV?
IUGR, seizures, hepatosplenomegaly, microcephaly
Sensorineural deafness is the most common symptom - CMV is the most common cause of this
What is the treatment for congenital CMV?
Ganciclovir
What is the varicella zoster virus responsible for and how is this transmitted?
This is also a Herpes virus - this is the virus responsible for chickenpox (varicella) in children and shingles in adults
Spread via droplet infection so is very infectious - respiratory spread
The later the mother develops this, the more damaging it is
What is the effect of VZV on the foetus?
Congenital varicella syndrome
The risk of this is greater in the second trimester than in the first
During the second trimester, development of the limbs occurs and so this will be impacted
Neonatal varicella
This occurs if the mother has VZV around the time of delivery (most severe if 5 days prior or 2 days post delivery)
This is transmission of the virus in utero and the foetus develops chicken pox following birth
What are the clinical presentations of VZV in the adult?
Dermatomal rash - this occurs because the VZV virus is reactivated from one dorsal root ganglia e.g. the opthalmic dorsal root ganglion would affect the eye
How is VZV diagnosed?
Look at the clinical presentations
Serology to see any antibodies to VZV
Swab of vesicle fluid for PCR usage
What is the treatment for VZV?
Prevention: vaccination - VZV immunoglobulin (this is a live vaccine so cannot be given during pregnancy
Treatment: (val)aciclovir - safe during pregnancy
