Fig. 2

Example of the TCD measurement in a 27-week plus 6-day old female fetus. For TCD measurements, the transducer was slightly rotated from the thalamic plane (used to measure HC) until the posterior fossa was visible. TCD was measured using the ‘outer-to-outer’ method. TCD taken during the research scan always showed LGA. This is due to the fact that the internal growth charts on the GE Voluson 8 Expert ultrasound scanner [60] did not cover this GA. However, all TCD were within expected 5–95 centile ranges