Introducing a Mobile-Connected Umbilical Doppler Device (UmbiFlow(™)) into a Primary Care Maternity Setting: Does This Reduce Unnecessary Referrals to Specialised Care? Results of a Pilot Study in Kraaifontein, South Africa

OBJECTIVES: UmbiFlow™ is a mobile-connected Doppler device that utilises a continuous waveform to measure resistance in the umbilical artery. The main aim of this pilot study was to determine whether the use of UmbiFlow™ for umbilical artery Doppler in patients with a suspected decreased symphysis fundal (SF) growth could safely lead to a decreased number of patients requiring referral to a more specialised level of care. A secondary aim of the study was to evaluate the effectiveness of UmbiFlow™ Doppler as a screening tool for concealed placental insufficiency in late bookers by using a single screening cut-off value that will be abnormal for any gestation >28 weeks. METHODS: The cohort comprised two groups of patients: The first group included all follow-up patients with suspected intra-uterine growth restriction (a decreased symphysis-fundus measurement based on serial assessment) who underwent on-site UmbiFlow™Doppler testing performed by the midwife directly after the clinical examination. The second group included late bookers, where gestation was uncertain; but estimated >28 weeks based on clinical grounds. This group was comprised of unselected patients who report to antenatal care late for the first time and received an UmbiFlow™Doppler test for concealed placental insufficiency. RESULTS: UmbiFlow™Doppler could reduce the number of false referrals to hospital by 55%. A single UmbiFlow™Doppler test in late bookers appeared to identify a group of women at moderate risk of lower birth weight babies.