First-trimester biochemical levels

The biochemical levels of the first trimester (B-HG, PAPP-A and PIGF) are obtained from maternal blood and are sampled between weeks 9 and 13 of gestation, and combined with maternal screening ultrasound of the first trimester we can obtain rates of detection up to 92 percent for chromosome abnormalities such as Down syndrome and severe preeclampsia at early onset.