PAPPA and obesity due to melanocortin 4 receptor deficiency: A first-trimester model based on multiparity, pregestational BMI, and plasma protein A (PAPP-A) amounts had 55% sensitivity and 79% specificity.[6] Another first-trimester model for LGA considering nuchal translucency, β-human chorionic gonadotrophin, and PAPP-A also had moderate accuracy.[7] Other models are limited to mothers with obesity[8] or diabetes,[9] lacking generalizability.