Sequential fetal serum β2-microglobulin to predict postnatal renal function in bilateral or low urinary tract...

Area of Science:

• Perinatology
• Fetal Medicine
• Pediatric Nephrology

Background:

• Fetal serum β2-microglobulin (S2M) is a known predictor of postnatal renal outcome in fetal obstructive uropathy.
• Serial measurements may offer improved predictive accuracy over single assessments.

Purpose of the Study:

• To evaluate the efficacy of serial fetal serum β2-microglobulin measurements in predicting postnatal renal outcome.
• To compare the predictive value of serial versus single S2M measurements and amniotic fluid volume.

Main Methods:

• Retrospective study of 42 fetuses with bilateral or low urinary tract obstruction.
• Serial fetal blood sampling for β2-microglobulin assay and recording of amniotic fluid volume.
• Renal outcome classified as favorable (normal function) or adverse (chronic renal failure/dysplasia).

Main Results:

• Serial S2M measurements showed significantly higher sensitivity (96.4%) than single measurements (64.3%) in predicting adverse renal outcome.
• Serial amniotic fluid volume assessment also demonstrated improved sensitivity (75.0% vs 35.7%).
• Prediction accuracy was higher when using the last S2M measurement, especially in cases with differing serial values.

Conclusions:

• Sequential measurement of fetal serum β2-microglobulin is more accurate for predicting postnatal renal outcome than a single assay.
• This improved accuracy may be linked to the progression of renal injury over time in obstructive uropathy.
• Serial monitoring is recommended for fetuses with adverse ultrasound findings, such as renal abnormalities or decreased amniotic fluid.