Extent of absent end-diastolic flow in umbilical artery and outcome of pregnancy.

Objective: To investigate if the extent of absent end-diastolic flow (AEDF) on umbilical artery (UA) Doppler velocimetry predicts pregnancy outcome.

Methods: This was a retrospective observational study based on data from 25 000 Doppler examinations of UA flow performed between 1998 and 2017 at the Blood Flow Laboratory, Level III Perinatal Center, Lund, Sweden. All pregnancies with AEDF in the UA were identified, and the duration of AEDF as a proportion of the total duration of the cardiac cycle (T /T ratio) was measured in digital images of the Doppler spectrum recorded at the last examination showing AEDF before delivery.

Cerebroplacental ratio as predictor of adverse perinatal outcome in the third trimester.

Introduction: Fetal growth restriction is associated with adverse perinatal outcome and the clinical management of these pregnancies is a challenge. The aim of this study was to investigate the potential of cerebroplacental ratio (CPR) to predict adverse perinatal outcome in high-risk pregnancies in the third trimester. Another aim was to study whether the CPR has better predictive value than its components, middle cerebral artery (MCA) pulsatility index (PI) and umbilical artery (UA) PI.

Infant outcome after active management of early-onset fetal growth restriction with absent or reversed umbilical artery blood flow.

Objective: To describe the short- and long-term outcomes of infants with early-onset fetal growth restriction (FGR) and umbilical artery absent or reversed end-diastolic flow (AREDF), delivered before 30 weeks' gestation and managed proactively.

Methods: This was a retrospective cohort study of fetuses delivered for fetal indication before 30 completed weeks' gestation that had early-onset FGR (defined as estimated fetal weight more than 2 SD below the mean) with AREDF in the umbilical artery (FGR group), at the level-3 perinatal unit in Lund, Sweden, between 1998 and 2015. Perinatal outcome and neurodevelopment at ≥ 2 years of age in surviving infants were compared with those of a group of infants without small-for-gestational-age birth weight or any known fetal Doppler changes delivered before 30 weeks in Lund during the corresponding time period (non-FGR group).

Doppler Audio Signal Analysis as an Additional Tool in Evaluation of Umbilical Artery Circulation.

 To investigate the predictive capacity of a new method for sound spectrum analysis of Doppler signals recorded from the umbilical artery in high-risk pregnancies.  The retrospective study comprised 127 pregnant women with various pregnancy complications between 23 and 39 gestational weeks. Umbilical artery blood flow velocity waveforms were recorded with Doppler ultrasound and characterized by pulsatility index (PI) and blood flow class (BFC).

Audio spectrum analysis of umbilical artery Doppler ultrasound signals applied to a clinical material.

Analysis of umbilical artery flow velocity waveforms characterized by pulsatility index (PI) is used to evaluate fetoplacental circulation in high-risk pregnancies. However, an experienced sonographer may be able to further differentiate between various timbres of Doppler audio signals. Recently, we have developed a method for objective audio signal characterization; the method has been tested in an animal model.