Increased maternal serum activin A but not follistatin levels in pregnant women with hypertensive disorders

Activin A levels are elevated in maternal serum of pregnant women with hype rtensive disturbances. Because follistatin is a circulating binding protein for activin A, the present study was designed to evaluate whether serum fo llistatin and activin A levels also change in patients with hypertensive di sorders in the last gestational trimester. The study design was a controlle d survey performed in the setting of an academic prenatal care unit. Health y pregnant women (controls, n = 38) were compared with patients suffering f rom pregnancy-induced hypertension (PIH, n = 18) or pre-eclampsia (n = 16). In addition, the study included a subset of patients with pre-eclampsia as sociated with intrauterine growth restriction (IUGR, n = 5). Maternal blood samples were withdrawn at the time of diagnosis (patients) or ma random pr enatal visit (controls), and serum was assayed for follistatin and activin A levels using specific enzyme immunoassays. Hormone concentrations were co rrected for gestational age by conversion to multiples of median (MoM) of t he healthy controls of the same gestational age. Follistatin levels were no t different between controls and patients, while activin A levels were sign ificantly increased in patients with PIH (18 MoM), pre-eclampsia (4.6MoM), and pre-eclampsia + IUGR (3.2 MoM, P < 0.01, ANOVA). The ratio between acti vin.A and follistatin was significantly increased in patients with :PIH (1. 5 MoM) and was further increased in patients with pre-eclampsia (4.5 MoM) a nd in the group with preeclampsia + IUGR (2.6 MoM). Follistatin levels were positively correlated with gestational age in control subjects (r = 0.36, P < 0.05) and in patients with PIH (r = 0.46, P < 0.05) or pre-eclampsia (r = 0.61, P < 0.01), while activin. A correlated with gestational age only i n the healthy control group (r = 0.69, P < 0.0001). The finding of apparent ly normal follistatin and high activin A levels in patients with PIH, and p re-eclampsia suggests that unbound, biologically active, activin A is incre ased in women with these gestational diseases.