Approach to investigation and management of proteinuria in pregnancy.

Pregnancy leads to significant changes in renal physiology, which result in increases in glomerular filtration rate (GFR) and enhanced protein excretion. These changes may continue in the postnatal period and might be observed for 5-6 months after birth. Once confirmed, proteinuria warrants investigation and close surveillance. Clinicians should establish the level of excretory kidney function and the presence or absence of proteinuria at booking/diagnosis. A history of proteinuria, PET and anti-hypertensive requirements in previous pregnancies is a helpful guide to what to expect in the current pregnancy. Maternal physiological adaptations mean that yet-undiagnosed kidney disease is unmasked during pregnancy. New onset of proteinuria before 20 weeks' gestation (with or without kidney impairment) suggests known or previously undetected kidney disease. As pregnancy evolves, hyperfiltration may lead to increasing proteinuria, posing a diagnostic challenge in the diagnosis and recognition of pre-eclampsia. This article was written as a guide for the evaluation and management of proteinuria in pregnancy, as well as appreciating diagnostic dilemmas.