Pregnancy

Pregnancy

Renal colic is the leading cause of non-obstetric hospital admission in pregnancy . The physiological changes that take place during preg - nancy include an increase in glomerular filtration rate by 50%; increased excretion of calcium, uric acid and sodium; and increased excretion of inhibitors of crystallisation such as citrate and magnesium. Urine pH is alkaline and so the pre - dominant stone type seen in pregnancy is calcium phosphate stones. US is the primary mode of investigation for renal colic. MRI can be used as a second-line investigation to define the - level of obstruction. Most stones pass spontaneously . Ho wever, stones can cause loss of pregnancy and prematur e labour. Hence, emergency ureteroscopy is a reasonable first-line option in well-selected distal ureteric stones. Inter nal stenting or PCN can be used in the interim and a definitive procedure can be planned fol - lowing childbirth. Pregnancy is an absolute contraindication to SWL.