Cuzick's trend test analysis of placental changes across ordered groups by number of P. vivax infections during pregnancy†.

†Women were divided according to the number of P. vivax infections that were diagnosed microscopically during pregnancy.aCuzick's trend test was performed across the ordered groups: no P. vivax infection (0), one P. vivax infection (1) and two or more P. vivax infections (2+). (z) Measure and direction of tendency.