To carry out a measurement of AFL, a sample of amniotic fluid of between 250-500 microliters is needed. In normal cases, the amniotic fluid that flows out spontaneously after the membranes have broken, is collected and analysed for the concentration of lactate (AFL® test).
The amniotic fluid is in some cases contaminated by foreign substances such as e.g. vaginal secretion and meconium. These substances are filtered away in the device and do not affect the measurement.