RENAL TUBULAR ACIDOSIS IN PREGNANCY

Abstract

Introduction:

Renal tubular acidosis(RTA) in pregnancy is a very rare disorder.It is usually associated with an inability to excrete hydrogen ions and/or a defect in the reabsorption of bicarbonate.This results in significant systemic acidosis, hypokalemia, hypocalcemia, and hypercalciuria.RTA is a chronic disease,mostly in childhood, and if untreated may lead to delay in growth.Patients are maintained on oral sodium bicarbonate and potassium supplementation for life.

Case report:

A 33-year-old lady, previously healthy, who started the prenatal care uneventfully until 30 weeks, developed easily fatigue,weakness proximal part of upper limb and lower limb.No other symptoms such as fever, dysuria, contraction pain, pervaginal bleeding, vomitting or diarrhea.Examination revealed a blood pressure 131/84, heart rate 88, sugar 6.5 mmol.Having weakness over proximal upper limb. White cell count 12.9, hemoglobin 13.3, platlet 314, sodium 138, potassium 2.0,creatine kinase 1795,magnesium 1.17, calcium 2.21.Urinalysis unremarkable.Venous blood gases pH of 7.43, bicarbonate of 19.8 and base deficit of 6.2.She started on intravenous and oral potassium correction together with intravenous magnesium sulphate.Potassium and creatine kinase normalised to 4.2 and 14 and the symptoms resolved.

Discussion:

RTA divided into four different types.Distal RTA(type I) is due to an inability of the distal tubule to excrete hydrogen ions.Proximal RTA(type II) is due to an inability of the proximal tubule to reabsorb bicarbonate.Type III is a combination of both, while type IV is associated with diffuse distal tubular dysfunction.Types I and II are more common.Hypokalemia may be severe in some cases of distal RTA.Rhabdomyolysis due to muscle ischemia is a rare manifestation of severe hypokalemia.There are several reports in the medical literature of pregnant patients with RTA. Pregnancy is known to worsen RTA.The majority of patients(86%) presented with preterm labor.Other complaints are painful cramps and proximal muscle weakness in both lower limbs.