First-trimester levels of pregnancy-associated plasma protein A2 (PAPP-A2) in the maternal circulation are elevated in pregnancies that subsequently develop preeclampsia.

Crosley EJ, Durland U, Seethram K, MacRae S, Gruslin A, Christians JK.

Reprod Sci. 2014 Jun;21(6):754-60. doi: 10.1177/1933719113512532. Epub 2013 Dec 13.
https://www.ncbi.nlm.nih.gov/pubmed/24336677