Objective: To investigate whether the reported increase in maternal serum activin A concentration in pre-eclampsia is evident from the first trimester.
Design: This was a case-control study carried out in antenatal clinics among singleton pregnancies at 10-14 weeks of gestation.
Methods: Activin A concentration was measured in stored maternal serum samples obtained at 11-14 weeks of gestation from 131 women who subsequently developed pre-eclampsia, 77 who developed non-proteinuric pregnancy-induced hypertension, 141 with fetal growth restriction in the absence of hypertensive complications and from 494 normotensive controls.
Results: Compared to the median activin A level in the control group (1.00 MoM), the median MoM in the patients who subsequently developed pre-eclampsia and pregnancy-induced hypertension (1.49 MoM and 1.32 MoM, respectively) was significantly increased (p < 0.001), and in patients with fetal growth restriction (1.02 MoM) it was not significantly different (p = 0.57). In the pre-eclampsia group (n = 131) the disease was considered to be sufficiently severe to necessitate iatrogenic delivery before 35 weeks in 25 patients, and in this group the median MoM was 1.92.
Conclusion: Maternal serum activin A concentration at 12 weeks of gestation in pregnancies which subsequently develop hypertensive disease is increased, whereas in those complicated by fetal growth restriction it is normal.