Pregnancy physiology pattern prediction study (4P study): protocol of an observational cohort study collecting vital sign information to inform the development of an accurate centi... door Kumar, F, Kemp, J, Edwards, C, Pullon, R, Loerup, L, Triantafyllidis, A, Salvi, D, Gibson, O, Gerry, S, MacKillop, L, Tarassenko, L, Watkinson, P