Pre-eclampsia is a serious condition both for the mother and the fetus. It is associated with inadequate placentation and reduced blood supply to the intravillous space of the developing placenta. Women who develop pre-eclampsia show impaired resistance to the pressor effect of angiotensin II, which can be demonstrated before the development of hypertension. Early detection of patients at risk allows for early intervention.
Types of pre-eclampsia:
(1) nonproteinuric: rise in diastolic blood pressure >= 25 mm Hg, AND diastolic blood pressure > 90 mm Hg, without proteinuria
(2) proteinuric: same as (1), with proteinuria > 1+ on dipstick
Specimen Collection:
(1) random, untimed urine sample
(2) collected between 16 and 20 weeks of pregnancy
ratio of inactive urinary kallikrein to creatinine =
= (inactive urinary kallikrein in mU/mL) / (creatinine in µmol/mL)
where:
• The conversion factor for creatinine from mg/dL to µmol/mL should be 0.0884.
Interpretation:
• The median ratio in women who developed pre-eclampsia was 78.27
• The median ratio in women who did not develop pre-eclampsia was 358.19
• A ratio <= 170 predicted pre-eclampsia with a sensitivity of 70% and specificity of 86%
NOTE: Measurement of inactive urinary kallikrein does not appear to be readily available in the US at this time.
