1. INTRAPARTUM FETAL BLOOD SAMPLING – HOW MUCH IS ENOUGH?
Santangeli L, Ratnavelu N, Hair WM, Thomson AJ
Department of Obstetrics & Gynaecology, NHS Greater Glasgow & Clyde, Scotland
Introduction
Intrapartum fetal blood sampling (FBS) is a crucial tool in the assessment of fetal wellbeing. National guidelines exist providing guidance on how to interpret FBS results and what action is appropriate (NICE Guidance, 2007). No published guidance or evidence exists regarding the number of samples required to support clinical decision-making; we sought to address this in the current study.
Key results
10/50 women had an FBS pH <7.25.
In those patients whose first FBS pH was <7.20 (n=6), all subsequent samples were also abnormal.
In patients whose first pH was 7.20–7.25 (n=4), subsequent pHs varied (range ), but clinical decisions were based on the initial result.
FBS sampling times ranged from 6-45 minutes. In 6 patients, the sampling times took more than 35 minutes.
Methods
FBS were obtained from 50 labouring women. Other data gathered included; number of samples obtained and analysed, sampling time, pH values and subsequent clinical decisions. An abnormal FBS value necessitating delivery or re-sampling was defined as <7.25.
Conclusions
In those patients where FBS is indicated, there appears to be no benefit in obtaining more than one result
Multiple samples may lead to unnecessary delays in clinical decision-making
Consideration should be given to standardising practice amongst practitioners in labour ward
Results
160 samples were obtained (median per patient = 3, range 0-6), and 71% were processed successfully (the remainder were reported as “air, gas in sample, insufficient”).