INTRODUCTION
Intrahepatic cholestasis of pregnancy (IHCP) is the most common
hepatobiliary system disease of pregnancy that generally occurs in the
late second and third trimesters, with the variable incidence between
0,4% and 5% 1. It is diagnosed with new-onset
pruritus particularly in palms and soles of the feet and elevated
maternal serum bile acids and/or liver function enzymes. Even though
IHCP is known as a usually benign disease that is resolved in two or
three weeks after delivery, it is associated with adverse perinatal and
neonatal outcomes 2-4. Due to the severity of the
disease, higher incidence of obstetric complications such as preterm
delivery, meconium staining of amniotic fluid, respiratory distress,
fetal bradyarrhythmia and fetal demise has been observed1,2. The underlying pathophysiological mechanism to
explain these complications has been associated with raised bile acids
in fetal tissues 5. As in bile acid accumulation in
fetal myocardium, chronic exposure to bile acids disrupts fetal
pulmonary development and function by blocking surfactant production1,5. Moreover, in literature, it has been explained
that the higher bile acid concentration is detected in cord blood and
amniotic fluid, the lower level of pulmonary surfactant is produced and
respiratory distress syndrome (RDS) may be observed more often in those
newborns 6,7.
Respiratory distress syndrome that may complicate newborns even after
term deliveries, still remains the major cause of neonatal intensive
care unit (NICU) admissions, neonatal morbidity and mortality8. Due to its importance, to predict respiratory
complications before delivery, some different invasive techniques have
been described such as assessment of lecithin/sphingomyelin ratio of
amniotic fluid. However in the last decade, pulmonary artery
acceleration time (AT) to ejection time (ET) ratio (PATET) has been
studied as a non-invasive method evaluating pulmonary lung maturation8-11. It has been reported that low PATET ratio has
been a reliable ultrasonographic parameter that give tips on fetal lung
immaturity particularly has been studied on preterm,
small-for-gestational age fetuses 8,9.
Based on previous studies, we hypothesized that effect of IHCP on fetal
lung maturation might be detected as evaluating the impact of IHCP on
fetal pulmonary artery Doppler parameters. The primary aim of this study
was to determine whether PATET was altered in the fetuses whose mothers
were complicated by IHCP. The secondary aim was to investigate the
association between fetal pulmonary artery Doppler parameters with
neonatal outcomes in pregnancies complicated by IHCP.