Predicting respiratory distress syndrome in neonates from mothers with intrahepatic cholestasis of pregnancy

The spatial expression of mTORC2-AKT-IP3R signal pathway in mitochondrial combination of endoplasmic reticulum of maternal fetal interface trophoblast in intrahepatic cholestasis of pregnancy

OBJECTIVES

Intrahepatic cholestasis of pregnancy (ICP) is complicated by adverse fetal outcomes and even fetal death, the mechanism remains unclear. This study aims at evaluating the differential expression of mTORC2-AKT-IP3R signaling pathway, which accurately regulate Ca2+ transfer across mitochondria-associated membranes (MAMs) and determine the stress intensity experienced by endoplasmic reticulum (ER) and mitochondria, in patients diagnosed with ICP.

METHODS

We combined western blot analysis and placental immunofluorescence co-localization detection to assess the expression and co-localization of the mTORC2-AKT-IP3R signaling pathway in severe (maternal total bile acid (TBA) levels ≥40 μmol/L) and mild (maternal TBA 10-40 μmol/L) ICP.

RESULTS

Compared with the control and mild ICP groups, phosphorylated protein kinase B (p-AKT) levels were significantly upregulated in the severe ICP group. Placental Rictor levels were lower in the mild ICP group than in the control group and were further downregulated in the severe ICP group. IP3R3 and p-IP3R3 levels were lower in placentas in the severe ICP group than in those in the mild ICP and control groups. Moreover, the co-localization of IP3R3 and p-AKT in patients in the mild and severe ICP groups was significantly elevated compared with that in patients in the control group.

CONCLUSIONS

In patients with severe ICP, limited expression of Rictor and elevated p-AKT levels would suppress IP3R3/p-IP3R3 levels in MAMs. This inhibition might influence the transportation of Ca2+ from the ER to the mitochondria, thus weaken the stress adaptation associated with MAMs. Our results reveal the possible pathophysiological mechanism of adverse fetal outcomes in ICP.

Bile Acids Pneumonia: A Respiratory Distress Syndrome in Early-Term Neonates

Intrahepatic cholestasis of pregnancy (ICP) complicates among 0.2-2% of pregnancies and has been associated with adverse perinatal outcomes, including sudden stillbirth, meconium strained fluid, preterm birth, perinatal asphyxia, and transient tachypnea of the newborn. The diagnosis of "bile acids pneumonia" was previously proposed and a causative role of bile acids (BA) was supposed with a possible mechanism of action including surfactant dysfunction, inflammation, and chemical pneumonia. In the last few years, the role of lung ultrasound (LUS) in the diagnosis and management of neonatal respiratory distress syndrome has grown, and LUS scores have been introduced in the literature, as an effective predictor of the need for surfactant treatment among neonates with respiratory distress syndrome. We present four cases of infants born from pregnancies complicated by ICP, who developed respiratory distress syndrome early after birth. Lung ultrasound showed the same pattern for all infants, corresponding to a homogeneous alveolar-interstitial syndrome characterized by a diffuse coalescing B-line pattern (white lung). All infants evaluated require non-invasive respiratory support and in three cases surfactant administration, despite the near-term gestational age, with rapid improvement of respiratory disease and a good clinical outcome.

Ultrasound-assessed lung aeration, oxygenation and respiratory care in neonatal bile acid pneumonia: A nested case-control study

AIM

Neonatal bile acid pneumonia (NBAP) occurs in neonates following obstetric cholestasis. We aimed to study the lung aeration and respiratory support of NBAP.

METHODS

Nested, case/control study enrolling age-matched neonates with NBAP, respiratory distress syndrome (RDS) or transient tachypnoea (TTN). Lung aeration and oxygenation were assessed with lung ultrasound score, oxygenation index and SpO2 /FiO2 .

RESULTS

Nineteen, 22 and 25 neonates with NBAP, RDS and TTN, respectively were studied (mean gestational age = 33 (2.2) weeks, 30 (45.5%) males). Upon admission, RDS patients had the worst lung ultrasound score (p = 0.022) and oxygenation index (p = 0.001), while NBAP and TTN neonates had similar values. At the worst time-point, NBAP and RDS patients showed similar oxygenation index (NBAP: 4.6 [2], RDS: 5.7 [3]) and SpO2 /FiO2 (NBAP: 3.1 [1.1], RDS: 2.7 [1]) which were worse than those of TTN patients (oxygenation index: p = 0.015, SpO2 /FiO2 : p = 0.001). RDS neonates needed the longest continuous positive airway pressure and highest mean airway pressure, but NBAP neonates needed invasive ventilation (26.3%, p = 0.01) and surfactant (31.6%, p = 0.003) more often than TTN patients who never needed these.

CONCLUSION

NBAP was a mild disorder in the first hours of life but subsequently worsened and became similar to RDS.

Bile acids-induced lung injury: update of reverse translational biology

The presence of bile acids in lung tissue is associated with some clinical features observed in various medical specialties, but it took time to understand that these are due to a "bile acid-induced lung injury" since specific translational studies and cross-disciplinary awareness were lacking. We used a reverse translational approach to update and summarize the current knowledge about the mechanisms of bile acid-induced lung injury. This has been done in a cross-disciplinary fashion since these conditions may occur in patients of various age and in different medical fields. We here define these clinical conditions, then we review the physiopathology of these conditions and the animal models used to mimic them and, finally, their pathobiology. Mechanisms of bile acid-induced lung injury have been partially clarified overtime and are represented by: 1) the interaction with secretory phospholipase A2 pathway, 2) the effect on surfactant function and structure, 3) the biological effects on inflammation and local immunity, 4) the direct cellular toxicity. These mechanisms are schematically illustrated and histological comparisons between ARDS induced by bile acids and other triggers are also provided. Based on these mechanisms we propose possible direct therapeutic applications and, finally, we discuss further research steps to improve the understanding of processes that generate pathological clinical conditions.

Intrahepatic Cholestasis of Pregnancy Is Associated with Reduced Nitric Oxide Synthase (iNOS) in Plasma and Placentas: A Pilot Study

Background

Intrahepatic cholestasis of pregnancy (ICP) is a condition specific to pregnancy, leading to increased fetal morbidity and mortality. Nitric oxide synthase (iNOS) may be a factor regulating the vasodilation of blood vessels, which are relevant to ischemic-hypoxic conditions. We aimed to explore the potential relationship between iNOS and ICP.

Material/Methods

A prospective, case-control study was conducted including 77 pregnant women with ICP and 80 healthy pregnant women as controls. Enzyme-linked immunosorbent assays were used to investigate maternal plasma iNOS levels. The placenta mRNA levels and cell-specific localization of iNOS were determined by quantitative polymerase chain reaction, western blotting, and immunohistochemical analysis. A multivariate linear regression model was used to identify the independent factors of serum total biliary acids (TAB) in ICP.

Results

Compared with controls, the expression of iNOS was significantly lower in maternal serum and placentas with ICP (P<0.001). Maternal plasm iNOS levels were negatively correlated with TAB (r=−0.450, P<0.001), cholyglycine (r=−0.367, P<0.001), alanine aminotransferase (r=−.359, P<0.001), and aspartate aminotransferase (r=−0.329, P<0.001). iNOS level was an indicator for ICP by multivariate linear regression analysis (β=−0.505, P<0.001). The ROC curve indicated the optimal cut-off level for iNOS was 2865.43 pg/mL (sensitivity, 85.71%; specificity, 63.75%). The ROC curve area for iNOS was 0.793 (95% CI 0.722–0.864).

Conclusions

iNOS plays an important role in poor fetoplacental vascular perfusion and adverse pregnancy outcomes. iNOS can provide complementary information in predicting the extent and severity of ICP.

Echography-Guided Surfactant Therapy to Improve Timeliness of Surfactant Replacement: A Quality Improvement Project

OBJECTIVE

To improve time of surfactant administration with a surfactant replacement protocol based on semiquantitative lung ultrasound score (LUS) thresholds.

STUDY DESIGN

Quality improvement (QI), prospective, before-after, pilot study. In a 6-month period surfactant replacement was based only on inspired oxygen fraction (FiO₂) thresholds. In the second 6-month period, surfactant was given when either the FiO₂ or LUS exceeded the limits. The main QI measures were the proportion of neonates receiving surfactant within the first 3 hours of life and maximal FiO₂ reached before surfactant replacement. Secondary QI measures were the duration of respiratory support and ventilator-free days. Data were also collected for 1 year after the study to verify sustainability.

RESULTS

Echography-guided Surfactant THERapy (ESTHER) increased the proportion of neonates receiving surfactant within the first 3 hours of life (71.4%-90%; P < .0001) and reduced the maximal FiO₂ reached before surfactant replacement (0.33 [0.26-0.5]) vs 0.4 [0.4-0.55]; P = .005). The global need for surfactant did not significantly change. ESTHER also resulted in a significant decrease in duration of invasive ventilation and ventilator-free days.

CONCLUSIONS

ESTHER improved the timeliness of surfactant administration and secondary QI indicators related to surfactant replacement.

New insights into diagnosis and treatment of intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific disease, characterized by maternal pruritus and abnormal serum biochemistries in the late second and third trimester of pregnancy. The symptoms and abnormal biochemistries resolve rapidly after fetal delivery. As a diagnosis of exclusion, the diagnosis of ICP is based on unexplained pruritus with other causes and impaired liver function presenting with elevated serum liver transaminases and/or bile acids. It is considered as severe ICP when bile acid ≥ 40 μmol/L during pregnancy. The pathogenesis of ICP is still unclear. Adverse perinatal outcomes associated with ICP are focused on increased risk of preterm, meconium-stained amniotic fluid, and perinatal mortality. Unpredictable fetal hypoxia may result in intrauterine fetal death, fetal distress during birth and even stillbirth, and lead to an increase of iatrogenic preterm and cesarean section. The etiology and pathogenesis of fetal stress in ICP are not yet clarified, which may be associated with impaired infrastructure and decreased stress-compensatory in human utero-placental-fetal unit, and related with vascular constriction of chorionic veins and umbilical cord due to elevated bile acids in fetal serum and amniotic fluid. The essential measures of standard treatment of ICP include: (1) monitoring and evaluation of disease, uterine contraction and fetus; (2) prevention and treatment of uterine contraction; (3) treatment with ursodeoxycholic acid (500-1500 mg/d) alone or in combination with S-adenosylmehionine (800-1000 mg/d) or rifampicin (300-1200 mg/d) to promote drainage of bile acids; (4) promotion of fetal growth and lung development; (5) treatment with vitamin K1 before delivery to prevent maternal and fetal hemorrhage; (6) and timely termination of pregnancy. Gestational weeks, fetal condition and severity of disease need to be taken into account when obstetricians decide the time of termination. Elective early delivery is still an effective measure to avoid stillbirth during prolongation of gestational weeks.

Can routine laboratory parameters predict adverse pregnancy outcomes in intrahepatic cholestasis of pregnancy?

AIM

Our aim was to investigate whether any hematological changes readily detectable by simple complete blood count (CBC), as well as fasting and postprandial total serum bile acid (SBA) levels, have diagnostic values for the prediction of adverse pregnancy outcomes in intrahepatic cholestasis of pregnancy (ICP).

METHODS

A prospective, case control study was carried out including 217 pregnant women (117 women with ICP and 100 healthy controls). The main outcome measures investigated were preterm delivery, APGAR scores, and neonatal unit admission. A multivariate logistic regression model was used to identify the independent risk factors of adverse pregnancy outcomes.

RESULTS

Compared with controls, women with ICP had significantly higher mean platelet volume (MPV) (mean 10.2±1.0 vs. 11.0±1.3; P<0.001) and platelet distribution width (PDW) (mean 13.1±2.3 vs. 14.7±2.8; P<0.001) values. Analysis with logistic regression revealed that the probability of preterm delivery did not increase until MPV levels exceeded 11.2 fL [odds ratio (OR)=2.68, 95% confidence interval (CI)=1.13-6.32, P=0.025], and total bilirubin levels exceeded 0.6 mg/dL (OR=3.13, 95% CI=1.21-8.09, P=0.019). Considering the low APGAR scores, only increased postprandial total SBA levels of ≥51 μmol/L were found to be predictive significantly (OR=3.02, 95% CI=1.07-8.53, P=0.037).

CONCLUSIONS

Our study suggests that increased MPV and total bilirubin levels are associated with preterm delivery, and increased postprandial total SBA levels are predictive for low APGAR in ICP patients.

Fetal complications due to intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is the most common liver disorder of pregnancy. Diagnosis is based on the clinical picture, particularly the presence of pruritus with a deterioration of liver function tests, and typically elevated serum levels of total bile acids. ICP manifests in the second half of pregnancy, predominantly during the third trimester. Symptoms of the disease resolve spontaneously after delivery. Etiology is still not fully understood. Genetic defects in specific transport proteins, elevated levels of sex hormones, and various environmental factors are thought to play a role in the development of this disorder. Although practically benign for the pregnant woman, ICP represents a serious threat to the fetus. It increases the risk of preterm delivery, meconium excretion into the amniotic fluid, respiratory distress syndrome, and sudden intrauterine fetal death. Identifying fetuses at risk of ICP complications remains challenging. The ideal obstetrical management of ICP needs to be definitively determined. The aim of this review is to summarize the current knowledge on fetal complications of ICP and describe management options for their prevention.

Reduced plasma corticotropin-releasing hormone levels during late gestation in patients with intrahepatic cholestasis of pregnancy

OBJECTIVE

Intrahepatic cholestasis of pregnancy (ICP) may lead to sudden onset of stillbirth, which most likely is related to uteroplacental insufficiency and dysregulation of the fetal blood supply. The relaxing effect of corticotropin-releasing hormone (CRH) on blood vessels was measured to examine the role of CRH in the pathogenesis of ICP.

METHODS

Eighty normal pregnant women and 80 ICP patients were divided into four groups of 20 cases, respectively, each based on gestational age from week 34 to 37. Radioimmunoassay was used to measure CRH in plasma samples collected from all of the subjects.

RESULTS

Plasma CRH increased markedly from week 34 to 37 in both ICP and healthy patients, but the increase was lower in the ICP group. Plasma CRH was 322 ± 61 pg/ml in mild ICP cases at 37 weeks' compared to 1,066 ± 173 pg/ml in controls (p < 0.05), but only 218 ± 128 pg/ml in severe ICP (p < 0.05). Plasma CRH was significantly lower at all other measured time points in patients with severe ICP. In ICP patients, there was a negative correlation between plasma CRH and total bile acid (TBA).

CONCLUSION

A limited increasing CRH level and negative correlation of CRH with TBA were unveiled in ICP patients.

Fetal lung surfactant and development alterations in intrahepatic cholestasis of pregnancy

AIM: To investigate the association between total bile acid (TBA) level during intrahepatic cholestasis of pregnancy (ICP) and fetal lung surfactant alteration.

METHODS: We recruited 42 ICP and 32 normal pregnancy women in this study. The maternal blood, fetal blood and amniotic fluid TBA level were detected using a circulating enzymatic method. Umbilical blood pulmonary surfactant protein A (SP-A) was evaluated with enzyme-linked immunosorbent assay. High performance liquid chromatography was used for the determination of phosphatidyl choline (PC), phosphatidyl inositol (PI), lysolecithin (LPC) and sphingomyelin (SM). Amniotic fluid lamellar body was counted with a fully automatic blood cell counter. Fetal lung area and fetal body weight were calculated from data obtained with an iu22 color supersonic diagnostic set. Clinical information of a nonstress test, amniotic fluid properties and neonatal Apgar score, and birth weight were recorded for review.

RESULTS: The TBA level in maternal blood, fetal blood and amniotic fluid in the ICP group were significantly higher than that in the control group (maternal blood: 34.11 ± 6.75 mmol/L vs 4.55 ± 1.72 mmol/L, P < 0.05; fetal blood: 11.9 ± 2.23 mmol/L vs 3.52 ± 1.56 mmol/L, P < 0.05; amniotic fluid: 3.89 ± 1.99 mmol/L vs 1.43 ± 1.14 mmol/L, P < 0.05). Amniotic fluid PC and PI in the ICP group were significantly lower than that in the control group (PC: 65.71 ± 7.23 μg/mL vs 69.70 ± 6.68 μg/mL, P < 0.05; PI: 3.87 ± 0.65 μg/mL vs 4.28 ± 0.74 μg/mL, P < 0.05). PC/LPC ratio of the ICP group was lower than that of the control group (14.40 ± 3.14 vs 16.90 ± 2.52, P < 0.05). Amniotic LB in the ICP group was significantly lower than that of the control group ((74.13 ± 4.37) × 10⁹/L vs (103.0 ± 26.82) × 10⁹/L, P < 0.05). Fetal umbilical blood SP-A level in the ICP group was significantly higher than that of the control group (30.26 ± 7.01 ng/mL vs 22.63 ± 7.42 ng/mL, P < 0.05). Fetal lung area/body weight ratio of the ICP group was significantly lower than that of the control group (5.76 ± 0.63 cm²/kg vs 6.89 ± 0.48 cm²/kg, P < 0.05). In the ICP group, umbilical cord blood TBA concentration was positively correlated to the maternal blood TBA concentration (r = 0.746, P < 0.05) and umbilical blood SP-A (r = 0.422, P < 0.05), but it was negatively correlated to the amniotic fluid lamellar corpuscle (r = 0.810, P < 0.05) and fetal lung area/body weight ratio (r = 0.769, P < 0.05). Furthermore, umbilical blood TBA showed a negative correlation to PC, SM and PI (r_pc = 0.536, r_sm = 0.438, r_pi = 0.387 respectively, P < 0.05). The neonatal asphyxia, neonatal respiratory distress syndrome, fetal distress and perinatal death rates in the ICP group are higher than that of the control group.

CONCLUSION: ICP has higher TBA in maternal and fetal blood and amniotic fluid. The high concentration of TBA may affect fetal pulmonary surfactant production and fetal lung maturation.

Effect of bile Acid on fetal lung in rat model of intrahepatic cholestasis of pregnancy

Objective. To determine the correlation between maternal bile acid (BA) level and fetal pulmonary surfactant in rats and study the effects of BA on fetal lung in rat model of intrahepatic cholestasis of pregnancy. Methods. Forty pregnant rats were treated with (A) 5.5 mg/kg BA, (B) 1.4 mg/kg BA, and (C) 1 ml physiological saline. Levels of total bile acid (TBA), ALT, AST, TBIL, DBIL, and SP-A were determined and the lungs of fetal rats were analyzed for pathological changes. Results. Groups A and B intervened with BA showed significant higher level of TBA in both maternal and fetal serum, more mortality rate of fetal rats, more concentration of SP-A in fetal serum, and wider alveolus mesenchyme of fetal rats than the control Group C. Higher level of BA associated with increased fetal risk and lower numerical density of mitochondria in type II alveolar epithelial cells. The levels of TBA in maternal serum were found to have significant positive correlation with those in fetal serum and SP-A level but negatively with the area of alveolus and the numerical density of lamellar body. Conclusions. The TBA level in maternal serum showed significant association with lung pathological changes in fetal rats.

Secretory phospholipase A2 pathway in various types of lung injury in neonates and infants: a multicentre translational study

BACKGROUND

Secretory phospholipase A2 (sPLA2) is a group of enzymes involved in lung tissue inflammation and surfactant catabolism. sPLA2 plays a role in adults affected by acute lung injury and seems a promising therapeutic target. Preliminary data allow foreseeing the importance of such enzyme in some critical respiratory diseases in neonates and infants, as well. Our study aim is to clarify the role of sPLA2 and its modulators in the pathogenesis and clinical severity of hyaline membrane disease, infection related respiratory failure, meconium aspiration syndrome and acute respiratory distress syndrome. sPLA2 genes will also be sequenced and possible genetic involvement will be analysed.

METHODS/DESIGN

Multicentre, international, translational study, including several paediatric and neonatal intensive care units and one coordinating laboratory. Babies affected by the above mentioned conditions will be enrolled: broncho-alveolar lavage fluid, serum and whole blood will be obtained at definite time-points during the disease course. Several clinical, respiratory and outcome data will be recorded. Laboratory researchers who perform the bench part of the study will be blinded to the clinical data.

DISCUSSION

This study, thanks to its multicenter design, will clarify the role(s) of sPLA2 and its pathway in these diseases: sPLA2 might be the crossroad between inflammation and surfactant dysfunction. This may represent a crucial target for new anti-inflammatory therapies but also a novel approach to protect surfactant or spare it, improving alveolar stability, lung mechanics and gas exchange.

The active management of intrahepatic cholestasis of pregnancy

PURPOSE OF REVIEW

To review the literature regarding the active management of intrahepatic cholestasis of pregnancy.

RECENT FINDINGS

There has been an increasing trend toward the active management of cholestasis of pregnancy. This trend exists because clinicians have yet to discover adequate solutions to avert the morbidities and mortalities associated with the disorder. It is believed that early intervention by induction of labor before the 38th week of gestation will decrease the incidence of intrauterine fetal demise associated with cholestasis of pregnancy. It is also believed that treating the clinical symptoms of cholestasis with 2-5 ursodeoxycholic acid will improve maternal symptoms, facilitate the prolongation of pregnancy, and possibly improve fetal outcomes.

SUMMARY

The current literature encourages the induction of labor between 37-38 weeks' gestation in order to reduce the incidence of stillbirth in women with intrahepatic cholestasis of pregnancy. The most widely used medication for both the treatment of maternal pruritus and the elevations in maternal liver enzymes associated with cholestasis of pregnancy is 2-5 ursodeoxycholic acid. Neither mode of practice has been subjected to randomized clinical trials.

Predicting fetal asphyxia in intrahepatic cholestasis of pregnancy

PURPOSE

Intrahepatic cholestasis of pregnancy (ICP) is a disease associated with high-perinatal morbidity and mortality rates. It is important to have parameters that aid in predicting fetal outcomes. Certain parameters affecting asphyxia in newborns to mothers with ICP are evaluated in this study.

METHODS

One hundred eighty-seven cholestatic pregnancies were analyzed, retrospectively. Fetal asphyxia was defined as an APGAR score of less than 7 at 5 min postpartum. Predictors of asphyxia in ICP were analyzed by binary multivariate logistic regression analysis.

RESULTS

Thirty-six of the cholestatic pregnancies ended up having an asphyctic newborn at the time of delivery (19.2%). There was a statistically significance difference in the levels of total bile acids (TBA) (42.4 +/- 15.2 vs. 33.8 +/- 12.9 micromol/L, P < 0.01), HDL cholesterol (54.2 +/- 15.9 vs. 61.3 +/- 12.2, P = 0.01), total cholesterol (279.0 +/- 51.4 vs. 257.7 +/- 51.6, P = 0.02), and triacylglycerol (299.4 +/- 94.6 vs. 260.4 +/- 118.7) between the asphytic and nonasphytic group. Binary multivariate logistic regression analysis demonstrated that TBA levels (OR 1.04, 95% CI 1.01-1.08, P = 0.03) and exposure time (OR 1.11, 95% CI 1.05-1.17, P < 0.01) were the most important independent variables predicting fetal asphyxia in ICP.

CONCLUSIONS

In this study, it has been demonstrated that for the evaluation of fetal status, increased TBA levels in the mother and increased exposure time for the fetus to these increased values of TBA within the maternal circulation system help to predict increased risk of asphyxia in newborns to ICP mothers.

Bile acid-induced lung injury in newborn infants: a bronchoalveolar lavage fluid study

OBJECTIVES

Neonatal respiratory distress syndrome is associated with intrahepatic cholestasis of pregnancy, and bile acids may play a major role in neonatal bile acid pneumonia. Our aim was to demonstrate the bile acid presence in the bronchoalveolar lavage fluid of neonates affected by respiratory distress syndrome who were born from intrahepatic cholestasis of pregnancy and to investigate bile acid mechanisms of action in acute lung injury.

METHODS

In this prospective study, we enrolled 10 neonates delivered from intrahepatic cholestasis of pregnancy, affected by respiratory distress syndrome requiring mechanical ventilation (intrahepatic cholestasis of pregnancy group) and 2 control groups. The first group consisted of 20 infants with respiratory distress syndrome delivered from pregnancies without any sign of intrahepatic cholestasis of pregnancy (respiratory-distress-syndrome group), and the second group included 20 neonates with no lung disease who were ventilated for extrapulmonary reasons (no-lung-disease group). We measured bile acid and pH in the bronchoalveolar lavage fluid and serum bile acid levels in the first 24 hours of life.

RESULTS

Bile acids were measurable in the bronchoalveolar lavage fluid of all of the infants in the intrahepatic cholestasis of pregnancy group but were absent in the 2 control groups. Bronchoalveolar lavage fluid pH was not different among the 3 groups. Infants in the intrahepatic-cholestasis-of-pregnancy group had significantly higher serum bile acid levels compared with those in both of the control groups.

CONCLUSIONS

Bile acids are detectable in the bronchoalveolar lavage fluid of newborns from intrahepatic cholestasis of pregnancy affected by respiratory distress syndrome. Elevated serum bile acid levels in these infants allow us to hypothesize that bile acid reaches the lung after an uptake from the circulation. These findings strongly support a role for bile acid in causing bile acid pneumonia.