(1128) Continuous Intrapartum Fetal Lactate Monitoring: A First-in-Fetus Study using a Novel Multi-Modal Biosensor

Women (n=10) who had experienced an uncomplicated pregnancy and in whom vaginal birth was anticipated were consented to participate in the study. The biosensor was applied to the fetal scalp when in active labor, membranes ruptured and the cervix at least 3 cm dilated. Fetal heart rate and lactate outputs from the device were blinded to caregivers and patients. The sensor was removed immediately prior to birth. Umbilical cord arterial samples were collected at the time of birth for lactate analysis. A factory calibration method was developed using fetal lamb data to predict umbilical cord lactate. 

Results:

Of the 10 sensors applied contemporaneous acquisition of fetal heart rate and lactate current was obtained from 7 fetuses. Figure 1 demonstrates representative traces following processing and demonstrate a rise in lactate throughout labor. 

The mean time of sensor application was 276 minutes (range 28 minutes – 465 minutes), with intrapartum lactate measurements obtained from as early as 15 minutes. Using data from extensive preclinical testing in the fetal lamb, predicted umbilical cord lactate correlated with that obtained from blood gas analysis . Table 1 demonstrates the concordance between the predicted lactate and the umbilical cord lactate. Overall, the Mean Average Error (MAE) was 0.68 mmol/L.  User acceptability of the device was high and there were no significant adverse events noted. 

 




Conclusion:

This study establishes the feasibility of acquisition of continuous fetal lactate measurement and fetal heart rate with a single device. The approach has the potential to advance intrapartum care and improve neonatal outcomes. Larger clinical studies are planned.