A prospective cohort study on the prediction of fetal distress and neonatal status with arterial and venous Doppler measurements in appropriately grown term fetuses.

Abstract

To assess the predictive power of the cerebro-placental ratio (CPR) and the venous-arterial index (VAI) for the development of intrapartum fetal distress (FD) and neonatal intensive care unit (NICU) admission. Fetal umbilical artery, middle cerebral artery and umbilical vein Doppler measurements were obtained before the active phase of labor in 311 singleton pregnancies at ≥37weeks. A continuous electronic fetal monitorization was applied, and an umbilical cord blood sample was obtained for each participant. FD and NICU admission were the primary outcomes. Labor was concluded as uncomplicated spontaneous vaginal delivery (SVD) in 261 (83.9%) cases. The 22 (7.1%) FD cases were subdivided into FD with NICU admission (n: 7; 2.3%) and without NICU admission (n: 15; 4.8%). Six out of 7 (85.8%) FD with NICU admission cases were from nulliparous pregnancies. The combinatory indices (VAI and CPR) reached the highest sensitivity (31.8%) and negative predictive value (94.7%). None of the fetuses, distressed or non-distressed, with CPR≤10th percentile was born with a cord pH<7.20. FD frequency was increased in fetuses with a low CPR or low VAI. However, the Doppler patterns were heterogeneous in both subgroups: FD with and without NICU admission. FD seems to be a common endpoint of different circulatory-metabolic disturbances. Parity affects the FD frequency in a manner related but not limited to fetal arterial and venous circulation. Low CPR could be a part of the adaptive mechanisms providing metabolic preparedness for hypoxic episodes.