Evaluation of the 'SensPoint' Lactate Meter in the Estimation of Foetal Scalp Blood and Umbilical Cord Blood Lactate

A cardiotocograph (CTG) can be used in labour to assess the heartbeat and well-being of a baby. An abnormal CTG may be a sign that a baby has low oxygen levels (hypoxia) and is becoming distressed.

In this situation a blood test can be taken from the scalp of the baby. A high lactate level in the blood indicates that urgent delivery is required to prevent long-term harm to the newborn.

SensPoint is a new medical device that measures lactate. It has several potential benefits over the current method of measuring lactate in that it is a portable hand-held device (allowing for use in the delivery room), requires a much smaller volume of blood and produces results more quickly than the current method of measuring lactate.

Before a new device is adopted into clinical practice, it is important that it is first confirmed that it is accurate and reliable for its intended use. This study will evaluate the ability of the SensPoint device to accurately and reliably detect lactate in fetal and umbilical cord blood by comparing its performance to the reference device currently in use.

A cardiotocograph (CTG) can be used in labour to assess the heartbeat and well-being of a baby. An abnormal CTG may be a sign that a baby has low oxygen levels (hypoxia) and is becoming distressed.

In this situation a blood test can be taken from the scalp of the baby. A high lactate level or high acidity (low pH) in the blood indicates that urgent delivery is required to prevent long-term harm to the newborn.

Obtaining scalp blood can be difficult, time consuming and has a high failure rate. In the UK the majority of maternity units (including at North Bristol NHS Trust) will use a blood gas analyser to measure lactate. These are generally large, non-transportable devices located in or nearby the maternity unit. The blood gas analyser requires relatively large drops of baby's blood and due to it's fixed location, requires the midwife to leave the delivery room to process. Samples that are too small or contain air bubbles and blood clots will be rejected and need repeating. The process can take up to twenty minutes to complete.

After delivery blood from the umbilical cord is routinely obtained in high-risk deliveries for the measurement of pH and lactate. This establishes the wellbeing of the baby at the time of birth and can guide on-going treatment. Lactate in these samples is also measured using the blood gas analyser.

SensPoint is a new medical device that measures lactate. It has several potential benefits over the current method of measuring lactate in that it is a portable hand-held device (allowing for use in the delivery room), requires a much smaller volume of blood and produces results more quickly than the current method of measuring lactate.

Before a new device is adopted into clinical practice, it is important that it is first confirmed that it is accurate and reliable for its intended use. The researchers propose a study that will evaluate the ability of the SensPoint device to accurately and reliably detect lactate in both the laboratory and clinical setting by comparing its performance to the reference device currently in use.

The study will be divided into three parts:

1. Comparison of the SensPoint device and the reference device in laboratory prepared samples.
2. Comparison of the SensPoint device and the reference device using small volumes of leftover blood from umbilical cord blood testing obtained during routine care.
3. Comparison of the SensPoint device and the reference device using small volumes of leftover blood from foetal scalp sampling obtained during routine care.

All foetal blood samples utilised in this study are surplus to clinical requirements and would otherwise be discarded. Retrospective consent will be obtained.

For the purposes of ensuring validity, reliability and repeatability of the device the researchers will test 90 laboratory standard samples, 90 arterial and venous cord blood samples and 90 foetal scalp capillary blood samples.

This study will enable the research team to design a larger study directly comparing the two methods of measuring lactate, assessing factors such as speed and patient satisfaction.

Eligibility Criteria:
Inclusion Criteria:

* women who have a fetal blood sample or umbilical cord blood sampling as part of their care during childbirth

Exclusion Criteria:

* women in Prison