Revisiting the placental clock: Early corticotrophin-releasing hormone rise in recurrent preterm birth.

Abstract

ObjectiveTo determine if maternal plasma CRH and preterm birth history were associated with recurrent preterm birth risk in a high-risk cohort.Study designSecondary analysis of pregnant women with a prior preterm birth ≤35 weeks receiving 17-alpha hydroxyprogesterone caproate for the prevention of recurrent spontaneous preterm birth. All women with a 24-week blood sample were included. Maternal plasma CRH level at 24- and 32-weeks' gestation was measured using both enzyme-linked immunosorbent assay (ELISA) and extracted radioimmunoassay (RIA) technologies. The primary outcome was spontaneous preterm birth ResultsRecurrent preterm birth in this cohort of 169 women was 24.9%. Comparing women who subsequently delivered ConclusionIn women with a prior preterm birth, CRH levels were higher and had an earlier rise in women who experienced recurrent preterm birth. Second trimester CRH may be useful in identifying a sub-group of women with preterm birth due to early activation of the placenta-fetal adrenal axis. Assay methodology is a variable that contributes to difficulties in reproducibility of CRH levels in the obstetric literature.