GIP and atrial fibrillation: In comparison, 78.3% (65/83) of AF samples were positive; of these, 13.3% (11/83) were quantified (ranged from 6.25 to 25.5 ng GIP/mL and from 6.25 to 8.05 ng GIP/mL, in deliveries at second and third trimesters, respectively).