MicroRNA-132 is overexpressed in fetuses with late-onset fetal growth restriction

Background and Aims To evaluate the expression of microRNA 132 (miR-132) in fetuses with normal growth and in fetuses with late-onset growth restriction (FGR). Methods In a prospective cohort study, 48 fetuses (24 with late-onset FGR and 24 with normal growth) were scanned with Doppler ultrasound after 34 weeks to measure the umbilical artery and middle cerebral artery pulsatility indices and followed until birth. Subsequently, blood samples from the umbilical cord were collected to evaluate the expression of miR-132 by means of Real-time quantitative polymerase chain reaction, determining the existence of normality cut-offs and associations with birth weight (BW) centile, cerebroplacental ratio multiples of the median (CPR MoM), and intrapartum fetal compromise (IFC). Results In comparison with normal fetuses, late-onset FGR fetuses showed upregulation of miR-132 (33.94 +/- 45.04 vs. 2.88 +/- 9.32 2-ddC(t), p < 0.001). Using 5 as a cut-off we obtained a sensitivity of 50% and a specificity of 96% for the diagnosis of FGR, while for IFC these values were respectively 27% and 73%. Expression of miR-132 was associated with BW centile but not with CPR MoM. Finally, the best detection of IFC was achieved combining miR-132 expression and CPR MoM (AUC = 0.69, p < 0.05). Conclusion Fetuses with late-onset FGR show upregulation of miR-132. Further studies are needed to investigate the role of miR-132 in the management of late-onset FGR.