Changes during pregnancy
- Anatomical – ↑size by 1-1.5cm, dilated ureter (due to ↑progesterone which is a muscle relaxant)
- Physiological
- GFR increase by 80% in 2nd trimester
- By 20% in 3rd trimester
- Decreased BUN + creatnine
- Proteinuria – 300mg/day
- Bacteriuria – MC in pregnancy due to delayed emptying, stasis and vesico-ureteral reflux (VUR)
- Pre-eclampsia – HTN + proteinuria that develops after 20 gestational weeks and resolves with delivery
Acute RF in pregnancy
- Obstetric complications of ARF – haemorrhage from placenta previa , placental abruption, uterine atony
- Causes of ARF unique in pregnancy
- Pre-eclampsia / Eclampsia
- Severe PPH
- HELLP syndrome – hemolysis, elevated liver enzymes, low platelet count
Pre-eclampsia
- Characterised by proteinuria and HTN
- Due to epithelial damage, causes swollen intra-cap endothelial cells in glomerulus (HALLMARK)
- RF – very young or old woman, twins, DM, essential HTN
- CF – HTN (160/110), thrombocytopenia , ↑LDL, ↑liver enzymes, PU>2g, edema, headache, vision disturbance, epigastric pain, HELLP syn
- Treatment – delivery (definitive), dexamethasone to mature fetal lungs, MgSO4 (to prevent seizures)
Pyelonephritis – risk of PN is higher in pregnancy
- Treatment– hospitalisation + ceftriaxone
- If severe (immunocompromised/poor urine ouput) – IV ticarcillin-clavulanate or piperacillin-tazobactam
Diabetic nephropathy
- ↑risk of pre-eclampsia
- ACEI contraindicated, nifedipine (CCB) used instead
Asymptomatic bacteriuria – ↑risk of UTI as urine of preg women has higher nutrient content
Thrombotic microangiopathy – fibrin + platelet aggregate in microvasculature in kidney + brain
- Splitting of glomerular BM, endothelial cell swelling
- When it primarily affects the kidney it is HUS (usually post partum)
- Characterised by ↓RBCs, ↓platelets and ARF
- Etiology – S.dysenteriae, E.coli, S.typhi
- HUS can develop as a complication of pre-eclampsia
- When characterised by profound thrombocytopenia + neurological disturbances
- Thrombotic thrombocytopenic purpura (usually antepartum)
Acute fatty liver of preg – fatty infiltration of hepatocytes
Estimate eGFR is unreliable in pregnancy