Fig. 3

Definition of patient area- Focus on the IRIS named ‘Fressain’ (number equal to 592,540,000). IRIS of the Nord department are colored blue, whereas neighboring departments are green. The IRIS named ‘Fressain’ (number = 592,540,000) of the Nord department is highlighted in orange in (a) (left). All midwives accessible by car within 34 min of the Fressain IRIS are circled in orange. As shown in (b) (right), the patient area of the midwife highlighted in blue are 843 IRIS (in red and pale pink because they are accessible by car within 34 min). Accordingly, women living in the Fressain IRIS share this midwife with all the other highlighted IRIS. Depending on travel time, these 843 IRIS have different accessibility weightings (Red Zone: 4 to 16 min, (w) = 1; Pale Pink Zone: 17 to 34 min, w = ((15-d) / (15-5)) ^1.5)