102 pregnant women, suspected of placental insufficiency, according to their physical findings, were regularly monitored by various techniques which were related to the birth of a small-for-date infant ( < 10th weight percentile), and assessed by calculations of recognition, occurrence, and exclusion probabilities. High reliability was given by ultrasonic biometry, by human placental lactogen (HPL) and estriol both in serum, and placental perfusion measurements (113mIn) if they were within the normal range. Antepartum non-stressed cardiotocogram revealed probability rates similar to HPL in serum. Combinations of monitoring methods augmented the prognostic value, nevertheless a problem of relatively high numbers of false-positive findings remained. For large departments all methods are recommended; for smaller ones particularly antepartum cardiotocogram in combination with ultrasonic biometry is recommended.