Stones pregnancy

Question 1

prevalence

Answer 1

affects 1:200 pregnancies

Question 2

rate of intervention

Answer 2

15-30%

Question 3

when stones occur

Answer 3

in 2nd/3rd trimester

Question 4

net risk of stone formation

Answer 4

does not increase
increase GFR increases filtered urine Na, uric acid, calcium, oxalate
also hypercalciuria due to suppression of PTH
also physiological HN and ureteric SM dilatation due to progesterone
but also increased filtration of citrate, mg and glycoproteins

Question 5

physiological HN on right more than left

Answer 5

90% vs 10%
because of
compression by dilated right ovarian vein
ureterine dextrorotation
protection of left ureter by gas filled sigmoid colon

Question 6

antibiotics in pregnancy

Answer 6

Avoid trimethoprim – folate antagonist
Gentamicin – auditory vestibular damage
Nitrofurantoin – neonatal haemolysis
penicillins and cephalosporins safe in pregnancy

Question 7

rate of spontaneous passage

Answer 7

<80% due to ureteric dilatation