First in pregnancy continuous lactate monitoring using a minimally invasive microneedle device: a proof of concept study in healthy pregnant volunteers

Objectives Validation and testing of a microneedle device capable of continuously monitoring lactate concentrations in healthy pregnant volunteers. Setting Clinical research facility in a Liverpool hospital in the UK. Participants Seven healthy pregnant women over 18 years old, with no previously diagnosed medical conditions and no reported pregnancy complications, were able to exercise gently for 30 min and do similar exercise routinely. Results A healthy volunteer proof-of-concept study was carried out measuring lactate continuously during a period of rest and gentle exercise in pregnant women. Women wore a microneedle device during 30 min of gentle exercise in order to monitor their interstitial lactate levels continuously along with having blood draws at regular intervals. Participants completed a questionnaire about their experience (average pain score 0.43/10, average discomfort score 0.14/10). Interstitial lactate mirrored trends in venous lactate in response to exercise. Conclusions In maternity care, lactate levels are used to support decision-making, especially around evolving sepsis during labour or post-partum haemorrhage management. Little is known about lactate levels during labour; they are presumed to rise due to anaerobic respiration brought about by physical exertion. However, whether in labour or not, if lactate levels rise above 2 mM intervention is triggered in the form of broad-spectrum antibiotics for treatment or prevention of sepsis. Lactate concentration provides a snapshot of a woman’s current clinical condition, which may alter rapidly. The device has possible application during labour and childbirth, where it could have a significant impact by triggering timely interventions while reducing exposure to unnecessary antibiotics. Trial registration number West of Scotland Research Ethics Committee 4 and prospectively registered ( ISRCTN38095366 ).