PAPPA and gestational diabetes: Uniquely, this study showed that the strongest association between early pregnancy PAPP-A concentrations and an index from the week 28 OGTT was with HOMA IR, suggesting that the principal reason PAPP-A is related to the future development of GDM and high blood pressures is via regulation of insulin sensitivities (with high circulating glucose concentrations and blood pressures both being related to reduced insulin sensitivity).