Infections in pregnancy Flashcards
1
Q
methods of transmission of congenital infections
A
- Transplacental infections – infections having invaded the maternal blood stream and then go onto infect the fetus via the placenta
- Premature/immunocompromised fetus – more prone to becoming infected with disease
- Perinatal infections – acquired during delivery or time of birth e.g. Birth canal in the time of delivery
Skin abrasion/Birth trauma – e.g. scalp electrodes can provide passage of entry to pathogen
2
Q
difference between primary vs secondary infections
A
- primary infections - refers to first encounter and infection of the disease during active pregnancy
e. g. primary rubella and T.gondii infection - secondary infection - pathogen remains latent and can reactivate to affect subsequent and multiple pregnancies
3
Q
What are the most common causes of congenital infections?
A
- Toxoplasmosis - parasitic disease which can cause flue like illnesses
- Others
- Rubella
- CMV
- herpes/hiv
- Syphyllis
4
Q
maternal CMV infection
A
- 1 - 4% of women will have a primary CMV infection
- Most cases of CMV infections are asymptomatic
( glandular fever, persistent fever + pharyngitis) - 40% of primary CMV infections result in congenital infections
5
Q
congenital CMV infection
A
- infection is by transplacental transmission from mother to foetus
- most common congenital infection
6
Q
clinical features of CMV infections
A
- effect on fetus in first trimester
- blindness
- hearing loss
- mental retardation - After birth
- petichae
- jaundice
- hepatosplenomegaly
- microcephaly
7
Q
diagnosis of CMV
A
- test amniotic fluid after 22 weeks - detects congenital CMV infection
- After birth in first 3 weeks of life - detect CMV in urine or saliva
8
Q
treatment of CMV
A
- IV Ganciclovir treatment for congenitally affect neonates with CNS symptoms
- Antiviral not used to reduce risk
9
Q
Herpes simplex virus
A
a double stranded DNA virus which is sexually transmitted
- HSV 1 strain - found within orofacial lesions in the trigeminal ganglia
- HSV 2 strain - lumbosacral ganglia produces genital herpes
10
Q
transmission of HSV occurs ;
A
- 85% of cases during intrapartum period ( onset of labour through the delivery of the placenta)
- 5 % during pregnancy
- 30 - 50% in late trimester as there is not enough time for foetus to develop antibodies after exposure to the virus before birth
- postnatally -via coldsore/lesions on skin
11
Q
Management of primary/first episode of genital HSV infection in pregnancy
A
- Active lesions present at the onset of labour Caesarean section recommended + treat mother with acyclovir
- Active lesions are present within 6 weeks of expected onset of labour but cleared at the time of labour vaginal birth
- Active lesions present > 6 weeks before expected onset of labour vaginal delivery only
This is to prevent neonatal herpes by reducing exposure of foetus to HSV in genital secretions
12
Q
management of recurrent genital herpes with active lesions during pregnancy
A
- Lesions at the onset of labour consider caesarean section but risk of neonatal herpes is small ( 0%-3%) + treat mother with acyclovir
- Lesions before onset of labour Vaginal delivery only
13
Q
management of hsv
A
- Symptomatic genital herpes infections are confirmed by direct detection of HSV
- Swabs from conjunctivaem nasopharynx, mouth and anus can be used for HSV PCR ( high yield) or viral cultures
- Arrange for screening of other sexually transmitted diseases
- Aciclovir : an antiviral drug that is associated with a reduction in duration and severity of symptoms and decrease in the duration of viral shedding
14
Q
Varicella zoster infection
A
- is caused by varicella zoster virus (VZV), a herpes vitus which is transmitted by doplet spread
- Clinical features –
- Non immune pregnant women – more vulnerable to complications of chicken pox such as hepatitis, encephalitis or pneumonia
- Pneumonia occurs in 10% of women with chicken pox and is more severe at later gestations
3.
15
Q
Management
A
- Establish exposure and immunity at booking visit
- Test for immunity – Blood test to check for VZV IgG
If exposure to virus – VZIg antibody titres within 4 days of contact - Treat chickenpox in all adults with high dose acyclovir
