[The relationship of amniotic fluid volume and fetal renal function to fetal distress in intrauterine growth retardation].

The Hourly fetal urine production rate (HFUPR) was measured by ultrasound to evaluate the relationship between qualitative amniotic fluid volume (vertical depth of amniotic cavity) and fetal renal function. A positive correlation was found between HFUPR and neonatal birth weight (r = 0.625, p < 0.01), and between HFUPR and the vertical depth of the amniotic cavity (r = 0.615, p < 0.01). In three cases of IUGR complicated by fetal distress, the cyclicity of micturition disappeared and the vertical depth of the amniotic cavity was less than 30mm. The values for urinary beta 2-microglobulin were significantly higher in three neonates with fetal distress (15.00 +/- 1.00mg/L) than in healthy neonates (1.51 +/- 1.48mg/L) (p < 0.01). The mean value for vertical depth of the amniotic cavity in normal pregnancies was stable during pregnancy (mean +/- 2SD; 30-80mm). Thus patients with an amniotic cavity vertical depth less than 30mm were classified as decreased. In the IUGR group, the vertical depth of the amniotic cavity was normal in 81 patients, 14 of whom gave birth to a fetus with fetal distress. In contrast, the vertical depth of the amniotic cavity was decreased in 34 patients, 26 of whom gave birth to a fetus with fetal distress. The difference was significant (76.5% vs 17.3%, p < 0.01). The incidence of fetal distress was significantly related to the vertical depth of the amniotic cavity in the IUGR group.