Microglobulin is significantly elevated in women with idiopathIc polyhydramnios

OBJECTIVE: To investigate the role of letal β2-microglobulin (β2-M) as a marker of renal tubular function in pregnancies complicated bv poKlndramnios. STUDY DESIGN: Maternal srrum and amniotic fluid samples, were obtained from 40 pregnant women who gave birth to normal infams without congenital anomalies. Amniotic fluid uas obtained bv transabdominal amniocentesis. All patients gave informed cotisent tor participation in the stiuh. The study population was classified into Uvo groups according to t lie presence or absence of poh hvdr.immos. Group 1: (ionsisted of 20 women nith polvlivdramnios (API > 25 cm.) and Gorup 2: Included 20 women \\ith normal AK1. β'2-microglobulin levels were measuied f)\ speciti( and sensitive RIA. Data were analv/ed using Student's t-test. RESULTS: 1. Amniotic fluid β2-M concentraiions were significauth hiifher in pregnaiu les complicated by polvhydratnnios than in those with normal API: H 4 ±fi.7 fig ni. fig 'ml, respectively (p < 0.024); 2. A significant decrease in amniotk fluid concentration of β2-M was observed with advancing gesiational .ige (p < 0.001); 3. Maternal serum levels of β2-M were mit siatisiicaih different between both groups: 4. Gestational age at amniocentesis were similar in both groups (Group 1: 28.7 ± 4.6 wk. vs. Gnmp 2: 30.2 ±4.9 wk; N.S.). CONCLUSIONS: Polyhydramnios is associated with higher levels of amniotk fluid β2-microglobulin, and ma\ reflect in utero impairment of fetal rena! tubular function. This parameter mav then-lore become a useful means of assessing letal and. 01 neonatal renal function in conditions which impact on the renal tubular integrity.