Screening for infection - 1st trimester Flashcards
What are all pregnant women screened for?
Rubella, Hepatitis B, Syphilis, and HIV
Hepatitis B - if infected?
infected can provide passive and active immunisation for baby
Syphilis can be easily treated with?
penicillin
When does Congential rubella syndrome occur?
if a woman is infected with Rubella up to about 16 weeks of pregnancy.
What can Congential rubella syndrome result in? (4)
mental handicap, blindness, deafness and heart defects
what is offered to women who are not immune to rubella?
immunisation on postnatal discharge.
how can hep b be present?
- what can be provided?
chronic carrier state
- active and passive immunisation
what does congenital syphilis cause? (4)
intrauterine growth restriction, hepato-splenomegaly, anaemia, thrombocytopenia, skin rashes.
HIV has what scheme?
- what does this allow? (3)
Opt out
- use of anti-retroviral drugs to reduce viral load, usually delivery by caesarean section and avoidance of breastfeeding in order to reduce vertical spread. (20% vs 1%)
Screening for anaemia
- what week is it performed?
routine blood counts
- 28 weeks
Why is additional iron needed?
to make extra maternal red blood cells
- needed by the fetus and placenta
What is Isoimmunisation?
the development of antibodies against blood groups.
What is the commonest isoimmunisation ?
is Rhesus disease where anti-D antibodies occur.
If a Rhesus negative women is carrying a rhesus positive baby - what will she develop?
anti D antibodies if the fetal red blood cells enter the maternal circulation.
What do anti D antibodies in a phesus positive baby occur with ?
miscarriage beyond 12 weeks gestation
-surgical or medical evacuation of the uterus either due to miscarriage or termination, ectopic pregnancy, antepartum haemorrhage and at delivery.
When do anti D antibodies tend to develop?
following the first pregnancy.
What can cause fetal anemia?
- Rhesus positive fetus
- cross the placenta and lead to destruction of the fetal red blood cells
- can result in fetal death
Screening for Rhesus allows?
us to identify women at risk ie Rhesus negative and provide them with passive immunisation to destroy fetal RBCs in the maternal circulation before the maternal immune system has the opportunity to be activated and produce its own antibodies.
Screening women with pre-existing antibodies allows ?
those pregnancies to be monitored more closely to detect the development of fetal anaemia and provide treatment.
what is offered to all Rh negative women?
Anti D IgG at 28 weeks
- both prophylactically and after potentially sensitising events.
When are women offered Anti-D? what events need to have taken place?
any sensitising event (eg, vaginal bleeding or amniocentesis) to reduce risk of transplacental passage of antibodies
