PAPPA and spontaneous abortion: Subsequently, we conducted a multivariable regression analysis and after adjusting for confounding factors, we found that factors increasing the risk of miscarriage were maternal height (OR = 1.037; 95%CI: 1.002–1.073), history of autoimmune disorder (OR = 17.981; 95%CI: 1.166–277.252), monochorionicity (OR = 2.568; 95%CI: 1.65–3.998), high intertwin discordance in CRL (OR = 1.365; 95%CI: 1.256–1.483), low PAPP-A MoM (OR = 0.051; 95%CI: 0.021–0.122) and nuchal translucency above the 95th centile (OR = 7.170; 95%CI: 4.215–12.197).