Obstetric Qs Flashcards
Why and when is nitrofurantoin avoided in pregnancy?
3rd trimester
haemolytic anaemia
necrotising enterocolitis
Why and when is trimethoprim avoided in pregnancy?
1st trimester
folate antagonist, increases risk of neural tube defects
Why is co-amoxiclav avoided in pregnancy?
NEC
What things do they do when scanning at antenatal clinic?
AC, HC and FL (femur length)
liquor volume
doppler
Why are growth scans not done every 2 weeks?
Due to unsymmetrical growth patterns e.g. growth spurts in different parts of the body
What is low PAPP-A? what is it associated with?
Pregnancy associated plasma protein A
associated with low birth weight of baby as placenta may not work as well
What is UTI associate with in pregnancy?
risk of preterm labour
What is the difference between IUGR and SGA?
SGA-birth weight below the 10th percentile for appropriate gestational age
IUGR-describes a fetus that has not reached its full growth potential due to genetic or environmental factors. Growth is normal and then tails off
What are the centiles they look at?
97th, 50th, 3rd
Antenatal testing for what trisomy which?
21-Downs
18-Edwards
13-Pataus
What are the causes of polyhydraminos? (>700ml fluid)
multiple pregnancy diabetes gut atresia infection during pregnancy rhesus disease idiopathic
What risk assessments do they do at antenatal clinic?
SGA, PET, GDM, VTE
What is the antenatal testing for trisomy? and what do they involve?
1st line-Combined test
11-14 weeks
ultrasound-nuchal translucency (>6mm)
maternal blood test-beta hCG (higher greater risk), PAPPA (lower greater risk)
Triple test
14-20 weeks
maternal blood tests-beta hCG (higher greater risk), alpha fetoprotein (lower greater risk), serum oestriol (female sex hormone) (lower greater risk)
Quadruple test
14-20 weeks
identical to the triple test but also tests maternal inhibin-A (higher greater risk)
What is the Quadruple test for trisomy?
Done between 14-20 weeks beta hCG (high) alpha fetoprotein (low) inhibin-A (high) serum oestriol (low)
(greater risk)
What happens when downs risk score is above 1 in 150?
Women is offered amniocentesis (later in pregnancy) or chorionic villius sampling (before 15 weeks)
