Objectives: We sought to verify the association between maternal intrahepatic cholestasis of pregnancy (ICP) and neonatal respiratory distress syndrome (RDS) and to determine how bile acids levels alter the risk of developing neonatal RDS.
Methods: We extracted data from our divisional database about all of the newborns born during the years 2000-2004. We compared 77 neonates born from pregnancies complicated by ICP with 427 neonates in the same range of gestational age born from noncomplicated pregnancies. We studied maternal bile acids levels immediately before delivery in mothers with ICP and measured bile acid levels during the first 24 hours of life in their newborns.
Results: The incidence of RDS in newborns from cholestatic pregnancies was twice that the reference population (28.6% vs 14%). The multivariate analysis showed that the risk of RDS in these newborns was approximately 2.5 times higher than in control infants. Within the ICP group, maternal and neonatal bile acid levels of infants affected by RDS were not significantly higher than those of healthy infants. The multivariate analysis showed that a low gestational age was the most important risk factor, but the probability of respiratory distress syndrome also increased by 2 per thousand for every additional micromole of the interaction term "neonatal by maternal bile acids level."
Conclusions: Maternal ICP is significantly associated with the occurrence of RDS in the newborn. We hypothesize that bile acids can produce surfactant depletion in the alveoli reverting the reaction of phospholipase A2. This hypothesis could potentially be confirmed by bronchoalveolar lavage study.