Fetal cardiac dysfunction in intrahepatic cholestasis of pregnancy is associated with elevated serum bile acid concentrations

BackgroundIntrahepatic cholestasis of pregnancy (ICP) is associated with increased stillbirth risk. This study aimed to assess the relationship between bile acid concentrations and fetal cardiac dysfunction in ICP with or without ursodeoxycholic acid (UDCA) treatment.MethodsBile acid profiles and NT-proBNP, a marker of ventricular dysfunction, were assayed in umbilical venous serum from 15 controls and 76 ICP cases (36 untreated, 40 UDCA-treated). Fetal ECG traces were obtained from 43 controls and 48 ICP cases (26 untreated, 22 UDCA-treated). PR interval length and heart rate variability parameters (RMSSD, SDNN) were measured in two behavioural states (quiet and active sleep). Partial correlation coefficients (r) and median [IQR] are reported.ResultsIn untreated ICP, fetal total serum bile acids (TSBA, r=0.49, p=0.019), their hydrophobicity index (r=0.20, p=0.039), glycocholate (r=0.56, p=0.007) and taurocholate (r=0.44, p=0.039) positively correlated with fetal NT-proBNP. Maternal TSBA (r=0.40, p=0.026) and alanine aminotransferase (r=0.40, p=0.046) also positively correlated with fetal NT-proBNP. No significant correlations to NT-proBNP were observed in the UDCA-treated cohort. Fetal PR interval length positively correlated with maternal TSBA in untreated (r=0.46, p=0.027) and UDCA-treated ICP (r=0.54, p=0.026). Fetal RMSSD in active sleep (9.6 [8.8,11.3] vs. 8.7 [7.6,9.6] ms, p=0.028) and SDNN in quiet sleep (11.0 [9.5,14.9] vs. 7.9 [5.1,9.7] ms, p=0.013) and active sleep (25.4 [21.0,32.4] vs. 18.2 [14.7,25.7] ms, p=0.003) were significantly higher in untreated ICP cases than controls. Heart rate variability values in UDCA-treated cases did not differ to controls.ConclusionsElevated fetal and maternal serum bile acid concentrations in untreated ICP are associated with an abnormal fetal cardiac phenotype characterised by increased NT-proBNP concentration, PR interval length and heart rate variability. UDCA treatment partially attenuates this phenotype

Prefrontal cortex activation and young driver behaviour: a fNIRS study

Road traffic accidents consistently show a significant over-representation for young, novice and particularly male drivers. This research examines the prefrontal cortex activation of young drivers and the changes in activation associated with manipulations of mental workload and inhibitory control. It also considers the explanation that a lack of prefrontal cortex maturation is a contributing factor to the higher accident risk in this young driver population. The prefrontal cortex is associated with a number of factors including mental workload and inhibitory control, both of which are also related to road traffic accidents. This experiment used functional near infrared spectroscopy to measure prefrontal cortex activity during five simulated driving tasks: one following task and four overtaking tasks at varying traffic densities which aimed to dissociate workload and inhibitory control. Age, experience and gender were controlled for throughout the experiment. The results showed that younger drivers had reduced prefrontal cortex activity compared to older drivers. When both mental workload and inhibitory control increased prefrontal cortex activity also increased, however when inhibitory control alone increased there were no changes in activity. Along with an increase in activity during overtaking manoeuvres, these results suggest that prefrontal cortex activation is more indicative of workload in the current task. There were no differences in the number of overtakes completed by younger and older drivers but males overtook significantly more than females. We conclude that prefrontal cortex activity is associated with the mental workload required for overtaking. We additionally suggest that the reduced activation in younger drivers may be related to a lack of prefrontal maturation which could contribute to the increased crash risk seen in this population