IGF1 and microcephaly: Median (IQR) circulating levels of IGF-1 were higher in patients with severe microcephaly (162 [118-226] ng/mL vs 129 [91-163] ng/mL [to convert to nanomoles per liter, multiply by 0.131]; P = .01), but levels of IGFBP3 were not statistically significantly different.