Liver function tests in pre-eclampsia: importance of comparison with a reference range derived for normal pregnancy

Intrahepatic Cholestasis of Pregnancy during COVID-19 Pandemic

Background and Objectives: Intrahepatic cholestasis of pregnancy (ICP) stands as one of the most prevalent concerns in maternal-fetal medicine, presenting a significant risk to fetal health and often associated with liver dysfunction. Concurrently, the coronavirus-19 (COVID-19) infection can lead to hepatic cell injury through both direct and indirect pathways. Hypothetically, these two conditions may coincide, influencing each other. This study aimed to comparatively assess the incidence and severity of ICP before and during the COVID-19 pandemic. Methods: A retrospective cohort study was conducted, comparing the incidence and severity of ICP between January 2018 and February 2020 (pre-COVID-19 period) and March 2020 to March 2022 (COVID-19 period) across two hospitals, encompassing 7799 deliveries. The diagnosis of ICP was established using the ICD-10 code and defined as total bile acids (BA) levels ≥ 10 μmol/L. Statistical analysis included descriptive statistics, Chi-square and Mann-Whitney U tests, as well as multiple or logistic regression analysis. Results: A total of 226 cases of ICP were identified. The incidence of mild cholestasis (BA < 40 μmol/L) was lower during the pandemic compared to before (3% before versus 2%, p < 0.05), while the incidence of moderate and severe ICP remained unchanged (0.6% before vs. 0.4%, p = 0.2). Overall, the total incidence of ICP was lower during the pandemic (3.6% before versus 2.4%, p = 0.01). No significant differences were observed in severity (as defined by BA and liver function test levels), rates of caesarean section, or neonatal birth weights. Conclusions: During the COVID-19 pandemic, the total incidence of ICP appeared to be lower. However, this reduction was primarily observed in cases of mild ICP, potentially indicating challenges in detection or reduced access to medical services during this period. The incidence of moderate and severe ICP remained unchanged, suggesting that these forms of the condition were unaffected by the pandemic's circumstances.

Diagnostic Approach to Elevated Liver Function Tests during Pregnancy: A Pragmatic Narrative Review

Liver disease is not uncommon during pregnancy and is associated with increased maternal and fetal/neonatal morbidity and mortality. Physiological changes during pregnancy, including a hyperestrogenic state, increase in circulating plasma volume and/or reduction in splanchnic vascular resistance, and hemostatic imbalance, may mimic or worsen liver disease. For the clinician, it is important to distinguish among the first presentation or exacerbation of chronic liver disease, acute liver disease non-specific to pregnancy, and pregnancy-specific liver disease. This last group classically includes conditions such as hyperemesis gravidarum, intrahepatic cholestasis of pregnancy, liver disorders associated with the pre-eclampsia spectrum, and an acute fatty liver of pregnancy. All of these disorders often share pathophysiological mechanisms, symptoms, and laboratory findings (such as elevated liver enzymes), but a prompt and correct diagnosis is fundamental to guide obstetric conduct, reduce morbidity and mortality, and inform upon the risk of recurrence or development of other chronic diseases later on in life. Finally, the cause of elevated liver enzymes during pregnancy is unclear in up to 30-40% of the cases, and yet, little is known on the causes and mechanisms underlying these alterations, or whether these findings are associated with worse maternal/fetal outcomes. In this narrative review, we aimed to summarize pragmatically the diagnostic work-up and the management of subjects with elevated liver enzymes during pregnancy.

Pregnancy-Associated Liver Diseases

The liver disorders unique to pregnancy include hyperemesis gravidarum, intrahepatic cholestasis of pregnancy, acute fatty liver of pregnancy, and preeclampsia-associated hepatic impairment, specifically hemolysis, elevated liver enzymes, and low platelet count syndrome (HELLP). Their importance lies in the significant maternal and fetal/neonatal morbidity and mortality. Expeditious diagnosis and clinical evaluation is critical to ensure timely, appropriate care and minimize risks to the pregnant woman and her fetus/baby. A multidisciplinary approach is essential, including midwives, maternal-fetal-medicine specialists, anesthetists, neonatologists, and hepatologists.

Role of Salivary Uric Acid Versus Serum Uric Acid in Predicting Maternal Complications of Pre-Eclampsia in a Rural Hospital in Central India: A Two-Year, Cross-Sectional Study

Background

Hypertensive disorders during pregnancy are an important topic of concern, specifically in rural and remote areas of India where there is a lack of awareness and it is difficult to maintain proper follow-up of pregnant females to screen them for complications developed during pregnancy. Gestational hypertension and pre-eclampsia result in the abruption of the placenta, hemolysis, elevated liver enzymes, low platelet count syndrome, eclampsia, and disseminated intravascular coagulation, which can be a serious threat to the health of the mother and the fetus. Therefore, it is important to identify biomarkers for diagnosing and predicting the complications of pre-eclampsia that may aid the obstetric high-dependency units based in rural areas to tackle this important health hazard during pregnancy.

Methodology

A total of 180 singleton pregnant women of more than 34 weeks of gestational age were enrolled in this study. All women were divided into three groups (control group, severe pre-eclampsia, and non-severe pre-eclampsia) based on the severity of blood pressure and the presence of proteinuria (≥+1 by the dipstick method). Salivary and serum uric acid levels were measured through morning samples, and all patients were monitored for the development of complications and outcomes. Salivary uric acid and serum uric acid levels were correlated with each other and with maternal complications of pre-eclampsia.

Results

Mean salivary uric acid (mg/dL) in severe pre-eclampsia was (6.72 ± 0.49) significantly higher compared to non-severe pre-eclampsia (4.75 ± 0.94) and control (3.13 ± 0.43). Mean serum uric acid (mg/dL) in severe pre-eclampsia was (8.13 ± 0.87) significantly higher compared to non-severe pre-eclampsia (6.23 ± 0.76) and control (3.85 ± 0.46).The lowest best cut-off value of maternal salivary uric acid was 5.06 mg/dL, above which one can predict maternal complications with a diagnostic accuracy of 78.33%.

Conclusions

Salivary uric acid and serum uric acid levels are significantly raised in cases of pre-eclampsia in comparison to normal pregnancy. Salivary uric acid and serum uric acid are correlated significantly indicating that salivary uric acid can function as a cost-effective, novel marker to provide an idea about serum uric acid levels. The prognostic accuracy of salivary uric acid was good in predicting maternal complications among cases of pre-eclampsia (severe and non-servere) and early-onset maternal complications. Therefore, it may be utilized as a helpful marker to identify high-risk patients.

Physiological and metabolic adaptations in pregnancy: importance of trimester-specific reference intervals to investigate maternal health and complications

Diagnosis, prognostication, and monitoring of maternal health throughout pregnancy relies on laboratory testing, including but not limited to key markers of thyroid, hepatic, cardiac, hematology, and renal function. Dynamic physiological processes during gestation significantly influence the maternal biochemistry that supports both the mother and fetus. Resultant changes in blood biochemistry alter the expected values of common laboratory tests. However, the importance of pregnancy-specific reference intervals for laboratory test result interpretation and appropriate monitoring of maternal health and complications is underappreciated. Most clinical laboratories continue to use non-pregnant adult reference intervals for laboratory test interpretation in pregnancy. The current review summarizes and critically evaluates the available literature regarding physiological and metabolic adaptations in pregnancy and their influence on common biomarkers of health and disease. The main laboratory parameters discussed include thyroid, hepatic, metabolic, renal, hematology, inflammatory, and cardiac markers. Considering the available data, further studies are urgently needed to establish trimester-specific reference intervals in healthy pregnant women on updated analytical platforms. Without such data, the standard of clinical laboratory service in pregnancy remains compromised and affects the quality of maternal-fetal healthcare.

Transforming growth factor-beta and liver injury in an arginine vasopressin-induced pregnant rat model

Objective

Approximately 30% of preeclamptic pregnancies exhibit abnormal liver function tests. We assessed liver injury-associated enzyme levels and circulating transforming growth factor beta (TGF-β) levels in an arginine vasopressin (AVP)-induced pregnant Sprague-Dawley rat model.

Methods

Pregnant and non-pregnant Sprague-Dawley rats (n=24) received AVP (150 ng/hr) subcutaneously via mini-osmotic pumps for 18 days. Blood pressure was measured, urine samples were collected, and all animals were euthanized via isoflurane. Blood was collected to measure circulating levels of TGF-β1-3 isomers and liver injury enzymes in pregnant AVP (PAVP), pregnant saline (PS), non-pregnant AVP (NAVP), and non-pregnant saline (NS) rats.

Results

The PAVP group showed significantly higher systolic and diastolic blood pressure than both saline-treated groups. The weight per pup was significantly lower in the AVP-treated group than in the saline group (p<0.05). Circulating TGF-β1-3 isomer levels were significantly higher in the PAVP rats than in the NS rats. However, similar TGF-β1 and TGF-β3 levels were noted in the PS and PAVP rats, while TGF-β2 levels were significantly higher in the PAVP rats. Circulating liver-type arginase-1 and 5'-nucleotidase levels were higher in the PAVP rats than in the saline group.

Conclusion

This is the first study to demonstrate higher levels of TGF-β2, arginase, and 5'-nucleotidase activity in PAVP than in PS rats. AVP may cause vasoconstriction and increase peripheral resistance and blood pressure, thereby elevating TGF-β and inducing the preeclampsia-associated inflammatory response. Future studies should explore the mechanisms through which AVP dysregulates liver injury enzymes and TGF-β in pregnant rats.

Pregnancy-specific reference intervals for C-reactive protein improve diagnostic accuracy for infection: A longitudinal study

BACKGROUND AND AIMS

Infections are a major cause of maternal mortality. C-reactive protein (CRP), a commonly-used inflammatory marker, is widely used to inform diagnosis, but the upper limit of normal in pregnancy is uncertain. We have defined trimester-specific reference intervals for CRP and evaluated their diagnostic accuracy for infection.

MATERIALS AND METHODS

Development cohort: longitudinal study of pregnant women to determine 95% reference intervals. Evaluation cohort: diagnostic accuracy study to evaluate these intervals in 50 women with suspected intrauterine infection.

RESULTS

In these 322 healthy pregnant women, CRP was substantially higher than in most non-pregnant populations. CRP was similar in each trimester, with an upper reference limit of 19 mg/L. CRP increased linearly with body mass index (p < 0.0001). The sensitivity and specificity of CRP for diagnosing chorioamnionitis were 73% and 86%, respectively. The overall diagnostic accuracy using the pregnancy-specific reference interval was significantly better than that of the existing standard (p = 0.03).

CONCLUSIONS

CRP is a widely-used clinical tool in pregnancy, and a pregnancy-specific reference interval should be used to optimise diagnostic accuracy. Chorioamnionitis was used as an example of a localised infection with well-defined outcomes, but pregnancy-specific RIs for CRP should be considered in any clinical setting including pregnant women.

A pregnancy-specific reference interval for procalcitonin

BACKGROUND AND AIMS

Sepsis is a leading cause of maternal death, and developing diagnostic tests for infection is increasingly important to reduce maternal mortality. The existing inflammatory markers, like C-reactive protein, are not specific for infection, which introduces diagnostic uncertainty. Procalcitonin (PCT) is used to accurately diagnose bacterial sepsis and differentiate it from other conditions, which is now particularly important given the vulnerability to COVID-19 in pregnancy. There are few studies of PCT in pregnancy as the reference interval for pregnant women is unknown. This study aimed to define the pregnancy-specific reference interval for PCT.

MATERIALS AND METHODS

Cross-sectional study of 323 healthy pregnant women, with longitudinal sampling in each trimester.

RESULTS

The upper reference limit for PCT was 0.05 ng/mL and did not vary materially between any observed group of gestational age, body mass index, maternal age, mean arterial blood pressure or fetal sex.

CONCLUSION

Our study has shown that levels of PCT are similar in pregnant and non-pregnant populations despite the physiological changes of normal pregnancy. Therefore, pregnancy should not preclude the use of PCT in pregnant women with suspected sepsis, or for guiding antibiotic therapy in women with a diagnosed bacterial infection at any stage of pregnancy.

First trimester serum angiogenic and anti-angiogenic factors in women with chronic hypertension for the prediction of preeclampsia

BACKGROUND

An imbalance between angiogenic and antiangiogenic factors is thought to be a central pathogenetic mechanism in preeclampsia. In pregnancies that subsequently experience preeclampsia, the maternal serum concentration of the angiogenic placental growth factor is decreased from as early as the first trimester of pregnancy, and the concentration of the antiangiogenic soluble fms-like tyrosine kinase-1 is increased in the last few weeks before the clinical presentation of the disease. Chronic hypertension, which complicates 1-2% of pregnancies, is the highest risk factor for the development of preeclampsia among all other factors in maternal demographic characteristics and medical history. Two previous studies in women with chronic hypertension reported that first-trimester serum placental growth factor and soluble fms-like tyrosine kinase-1 levels were not significantly different between those who experienced superimposed preeclampsia and those who did not, whereas a third study reported that concentrations of placental growth factor were decreased.

OBJECTIVE

The purpose of this study was to investigate whether, in women with chronic hypertension, serum concentrations of placental growth factor and soluble fms-like tyrosine kinase-1 and soluble fms-like tyrosine kinase-1/placental growth factor ratio at 11⁺⁰-13⁺⁶ weeks gestation are different between those women who experienced superimposed preeclampsia and those who did not and to compare these values with those in normotensive control subjects.

STUDY DESIGN

The study population comprised 650 women with chronic hypertension, which included 202 women who experienced superimposed preeclampsia and 448 women who did not experience preeclampsia, and 142 normotensive control subjects. Maternal serum concentration of placental growth factor and soluble fms-like tyrosine kinase-1 were measured by an automated biochemical analyzer and converted into multiples of the expected median with the use of multivariate regression analysis in the control group. Comparisons of placental growth factor and soluble fms-like tyrosine kinase-1 levels and soluble fms-like tyrosine kinase-1/placental growth factor ratio in multiples of the expected median values between the 2 groups of chronic hypertension and the control subjects were made with the analysis of variance or the Kruskal-Wallis test.

RESULTS

In the group of women with chronic hypertension who experienced preeclampsia compared with those women who did not experience preeclampsia, there were significantly lower median concentrations of serum placental growth factor multiples of the expected median (0.904 [interquartile range, 0.771-1.052] vs 0.948 [interquartile range, 0.814-1.093]; P=.014) and soluble fms-like tyrosine kinase-1 multiples of the expected median (0.895 [interquartile range, 0.760-1.033] vs 0.938 [interquartile range, 0.807-1.095]; P=.013); they were both lower than in the normotensive control subjects (1.009 [interquartile range, 0.901-1.111] and 0.991 [interquartile range, 0.861-1.159], respectively; P<.01 for both). There were no significant differences among the 3 groups in soluble fms-like tyrosine kinase-1/placental growth factor ratios. In women with chronic hypertension, serum placental growth factor and soluble fms-like tyrosine kinase-1 levels provided poor prediction of superimposed preeclampsia (area under the curve, 0.567 [95% confidence interval, 0.537-0.615] and 0.546 [95% confidence interval, 0.507-0.585], respectively).

CONCLUSION

Women with chronic hypertension, and particularly those who subsequently experienced preeclampsia, have reduced first-trimester concentrations of both placental growth factor and soluble fms-like tyrosine kinase-1.

Implications of abnormal liver function in pregnancy and non-alcoholic fatty liver disease

Elevated liver enzyme levels can sometimes be encountered in asymptomatic pregnant women. Similar to non-pregnant subjects, women with elevated gamma glutamyltransferase or alanine aminotransferase in early pregnancy have increased risk of subsequent complications, especially gestational diabetes mellitus. In non-pregnant subjects, the commonest cause of abnormal liver function currently is non-alcoholic fatty liver disease. Risk factors include obesity, diabetes, and the metabolic syndrome. It can progress to hepatocellular carcinoma through the development of steatohepatitis, and has become the leading cause for liver transplantation in women. Found in as many as 16-18% of pregnant women, it is associated with an increased risk of pregnancy complications and abnormal foetal growth, which predisposes the offspring to the same problem subsequently. This condition probably explains the majority of the cases of "idiopathic" abnormal liver function in pregnancy, and should be looked out for in high-risk women owing to its implications on their long-term health outcome.

MIR146A rs2910164 (G/C) Polymorphism is Associated with Incidence of Preeclampsia in Gestational Diabetes Patients

Preeclampsia and gestational diabetes are common pregnancy disorders that may be interrelated. MIR146A rs2910164 (G/C) is a functional polymorphism that was associated with several diseases. This study aimed to investigate the frequency of rs2910164 polymorphism and its possible correlation with the incidence of preeclampsia in gestational diabetes patients. The study involved 250 pregnant women divided into 80 healthy control subjects, 85 gestational diabetes patients only, and 85 patients of gestational diabetes combined with preeclampsia. Systolic and diastolic blood pressures, urinary proteins, kidney and liver functions, glucose homeostasis parameters, and lipid profile were determined. Genotyping of the polymorphism was conducted by PCR-RFLP. The frequency of the minor C allele of rs2910164 polymorphism was significantly higher among patients of gestational diabetes combined with preeclampsia compared to the control group (p = 0.012) and the gestational diabetes group (p = 0.014). Patients of gestational diabetes and preeclampsia carrying CC genotype showed higher systolic and diastolic blood pressure, and increased urea, creatinine, urine protein, and dyslipidemia compared to the carriers of GG and GC genotypes. In conclusion, the results of the current study suggest that the rare CC genotype of MIR146A rs2910164 (G/C) polymorphism may be related to increased incidence of preeclampsia in gestational diabetes patients.

Sensitivity and Specificity of Biochemical Tests for Diagnosis of Intrahepatic Cholestasis of Pregnancy

BACKGROUND AND AIM

Intrahepatic cholestasis of pregnancy (ICP) is linked with increased risk of fetal complications. An accurate diagnostic test is needed to diagnose this disorder on time. We aimed to assess sensitivity and specificity of laboratory tests used for diagnosis of intrahepatic cholestasis of pregnancy and determine more reliable cut-off values of transaminases.

MATERIAL AND METHODS

Sixty one symptomatic patients with ICP and 29 healthy pregnant women were included in the retrospective analysis.

RESULTS

ICP patients had higher total bile acids (TBA) levels than healthy women (32 vs. 6; P < 0.0001) due to increase in cholic acid (CA) and chenodeoxycholic acid (CDCA). CA/CDCA ratio was significantly higher in ICP patients compared to healthy pregnant women (1.13 vs. 0.68; P < 0.00002). TBA, CA, CDCA and CA/CDCA ratio demonstrate the following sensitivity (94%, 96%, 89%, 71.9%) and specificity (63%, 63%, 59%, 79.3%, respectively) for ICP diagnosis. Lowering cut-off values for ALT (31 U/L) and AST (30 U/L) resulted only in minimal increase of sensitivity to 92.2% vs. 90.1% for ALT and to 92.2%, vs. 90.6% for AST.

CONCLUSION

The present study did not reveal any single specific and sensitive marker for reliable diagnosis of ICP. Establishment of lower cut-off values for transaminases activity might only minimally increase the accuracy of diagnosing ICP.

Gestational age-specific reference intervals for 15 biochemical measurands during normal pregnancy in China

Aims

Physiological changes that occur during pregnancy can influence biochemical parameters. Therefore, using reference intervals based on specimens from non-pregnant women to interpret laboratory results during pregnancy may be inappropriate. This study aimed to establish the essential reference intervals for a range of analytes during pregnancy.

Methods

A cross-sectional study was performed in 13,656 healthy pregnant and 2634 non-pregnant women. Fifteen biochemical measurands relating to renal and hepatic function were analysed using an Olympus AU5400 analyzer (Olympus, Tokyo, Japan). All the laboratory results were checked for outliers using Dixon’s test. Reference intervals were established using a non-parametric method.

Results

Alanine aminotransferase, aspartate aminotransferase, albumin, cholinesterase, creatinine, direct bilirubin, gamma-glutamyl transpeptidase, total bilirubin, total bile acid and total protein showed a decrease during the whole gestational period, while alkaline phosphatase and uric acid increased. Urea nitrogen, β2-microglobulin and cystatin-C fell significantly during the first trimester and then remained relatively stable until third trimester. Reference intervals of all the measurands during normal pregnancy have been established.

Conclusions

The reference intervals established here can be adopted in other clinical laboratories after appropriate validation. We verified the importance, for some measurands, of partitioning by gestational age when establishing reference intervals during pregnancy.

Prediction of adverse maternal outcomes from pre-eclampsia and other hypertensive disorders of pregnancy: A systematic review

BACKGROUND

The hypertensive disorders of pregnancy are a leading cause of maternal and perinatal mortality and morbidity. The ability to predict these complications using simple tests could aid in management and improve outcomes. We aimed to systematically review studies that reported on potential predictors of adverse maternal outcomes among women with a hypertensive disorder of pregnancy.

METHODS

We searched MEDLINE, Embase and CINAHL (inception - December 2016) for studies of predictors of severe maternal complications among women with a hypertensive disorder of pregnancy. Studies were selected in a two-stage process by two independent reviewers, excluding those reporting only on adverse fetal outcomes. We extracted data on study and test(s) characteristics and outcomes. Accuracy of prediction was assessed using sensitivity, specificity, likelihood ratios and area under the receiver operating curve (AUROC). Strong evidence of prediction was taken to be a positive likelihood ratio >10 or a negative likelihood ratio <0.1, and for multivariable models, an AUROC ≥0.70. Bivariate random effects models were used to summarise performance when possible.

RESULTS

Of 32 studies included, 28 presented only model development and four examined external validation. Tests included symptoms and signs, laboratory tests and biomarkers. No single test was a strong independent predictor of outcome. The most promising prediction was with multivariable models, especially when oxygen saturation, or chest pain/dyspnea were included.

CONCLUSION

Future studies should investigate combinations of tests in multivariable models (rather than single predictors) to improve identification of women at high risk of adverse outcomes in the setting of the hypertensive disorders of pregnancy.

Trauma and Considerations Unique to Pregnancy

Trauma complicates 6% to 7% of all pregnancies and requires multidisciplinary education and training for both trauma and obstetric teams to achieve the best outcome. It is important to understand the mechanisms of certain adverse maternal and fetal/neonatal outcomes incurred as a result of trauma, as well as caveats to pregnancy physiology that make some injuries more likely and detection of maternal compromise more difficult. This article focuses on these caveats and how to incorporate these into ongoing trauma protocols and offers suggestions for the formation of obstetric trauma response team.

Validation of reportable indices of haematology, liver and renal function in pregnancy for the Middle Eastern population

The objective of this study was to describe normative values of complete blood counts, kidney and liver function tests for Jordanian women. A prospective study of 797 healthy pregnant women, seen at the antenatal clinics of the Jordan University of Science and Technology, in Irbid, north Jordan, was conducted between January 2005 and December 2009. Differences by trimester were analysed using one-way ANOVA. The mean age of the women was 31.0 years. The mean gestational age at delivery was 38.2 weeks. It was concluded that complete blood counts, kidney and liver function values by trimester, of healthy pregnant population of Jordanian women, were consistent with data reported for other populations.

Liver disease in pregnancy

Changes in the liver biochemical profile are normal in pregnancy. However, up to 3% to 5% of all pregnancies are complicated by liver dysfunction. It is important that liver disease during pregnancy is recognized because early diagnosis may improve maternal and fetal outcomes, with resultant decreased morbidity and mortality. Liver diseases that occur in pregnancy can be divided into 3 different groups: liver diseases that are unique to pregnancy, liver diseases that are not unique to pregnancy but can be revealed or exacerbated by pregnancy, and liver diseases that are unrelated to but occur coincidentally during pregnancy.

Pregnancy and the liver

In pregnancy the liver can be affected by diseases specific to pregnancy as well as unrelated conditions. The possible effect of the disease and its management on both the fetus and mother must be considered. Several physiological changes occur during pregnancy as liver metabolism is altered. Serum protein concentrations fall, with a decrease in serum albumin in part the result of the dilutional effect of an increase in plasma volume. Alanine transaminase and aspartate transaminase levels decrease (Table 1), complicating the diagnosis of disorders involving subtle changes in liver function. Alkaline phosphatase is also produced by the placenta, making this an unreliable marker of liver dysfunction in pregnancy.

Maternal hepatic growth response to pregnancy in the mouse

Pregnancy is characterized by physiological adjustments in the maternal compartment. In this investigation, the influence of pregnancy on maternal liver was examined in CD-1 mice. Dramatic changes were observed in the size of the maternal liver during pregnancy. Livers doubled in weight from the non-pregnant state to day 18 of pregnancy. The pregnancy-induced hepatomegaly was a physiological event of liver growth confirmed by DNA content increase and detection of hepatocyte hyperplasia and hypertrophy. Growth of the liver was initiated following implantation and peaked at parturition. The expression and/or activities of key genes known to regulate liver regeneration, a phenomenon of liver growth compensatory to liver mass loss, were investigated. The results showed that pregnancy-dependent liver growth was associated with interleukin (IL)-6, tumor necrosis factor α, c-Jun and IL-1β, but independent of hepatocyte growth factor, fibroblast growth factor 1, tumor necrosis factor receptor 1, constitutive androstane receptor and pregnane X receptor. Furthermore, maternal liver growth was associated with the activation of hepatic signal transducer and activator of transcription 3, β-catenin and epidermal growth factor receptor, but pregnancy did not activate hepatic c-Met. The findings suggest that the molecular mechanisms regulating pregnancy-induced liver growth and injury-induced liver regeneration exhibit overlapping features but are not identical. In summary, the liver of the mouse adapts to the demands of pregnancy via a dramatic growth response driven by hepatocyte proliferation and size increase.

Accuracy of liver function tests for predicting adverse maternal and fetal outcomes in women with preeclampsia: a systematic review

BACKGROUND

Liver function tests are routinely performed in women as part of a battery of investigations to assess severity at admission and later to guide appropriate management.

OBJECTIVE

To determine the accuracy with which liver function tests predict complications in women with preeclampsia by a systematic review.

DATA

We conducted electronic searches without language restrictions in (1951-2010), (1980-2010) and the Cochrane Library (2009).

METHODS OF STUDY SELECTION

Primary articles that evaluated the accuracy of liver function tests in predicting complications in women with preeclampsia were chosen. Data was extracted by two reviewers independently. A bivariate model estimated area under the curve, sensitivity and specificity.

RESULTS

There were 13 primary articles including a total of 3 497 women assessing maternal (30 2×2 tables) and fetal (19 2×2 tables) outcomes. For predicting adverse maternal outcome, the point estimates of specificity were >70% in 18 tables with 0.79 (95%CI 0.51, 0.93). For predicting adverse fetal outcomes the specificity of the test was >70% in 2×2 tables. Sensitivity of the test was poor for both maternal and fetal outcomes.

CONCLUSION

In women with preeclampsia, function tests performed better in predicting adverse maternal than fetal outcomes. The presence of increased liver enzymes was associated with an increased probability of maternal and fetal complications, but normal liver enzyme levels did not rule out disease, as specificity was often higher than sensitivity.

BILIARY AND PANCREATIC DISEASE IN PREGNANCY

Pregnancy is a physiological condition that affects all organs. Diseases unrelated to pregnancy may present coincidentally during pregnancy or may be exacerbated by pregnancy, and may increase maternal and/or fetal morbidity or mortality. Compared with many other systems, the changes within the biliary tree and pancreas are relatively minimal. However, pregnancy is associated with an increased likelihood of cholelithiasis, which can have significant implications for the parturient.

Laboratory reference intervals during pregnancy, delivery and the early postpartum period

BACKGROUND

Physiological changes during pregnancy may affect laboratory parameters. Reference values based on samples from non-pregnant women are not necessarily useful for clinical decisions during pregnancy. There is a need to establish reference values during pregnancy in order to recognize pathological conditions.

METHODS

Eight hundred and one women with expected normal pregnancies were included in the study. Of these, 391 had no complications during pregnancy, delivery, or the early postpartum period. Blood samples were obtained at gestational weeks 13-20, 21-28, 29-34, 35-42, at labor, and 1 and 2 days postpartum. Reference intervals were calculated for 36 tests as recommended by the International Federation of Clinical Chemistry and Laboratory Medicine.

RESULTS

Many tests showed such large variations indicating that gestational age-specific reference intervals were necessary. Other tests had different but stable values when compared to non-pregnant women. A minor decrease in albumin levels was observed. This was not only due to pregnancy-associated hemodilution, since other components with the same or a larger molecular diameter did not show a similar decrease. Many tests exhibited a broad distribution around vaginal delivery and in the early postpartum period.

CONCLUSIONS

Only a few parameters were unaffected during uncomplicated pregnancy, delivery, and the early postpartum period suggesting that implementation of gestational age-specific reference intervals is necessary.

Antenatal detection of abnormal liver function tests - a marker for poor perinatal outcome

The purpose of this study was to examine (a) the incidence of liver disease diagnosed in our antenatal population, (b) the diagnostic value of initial symptoms and liver function tests (LFTs), (c) the adequacy of investigation and management of the liver disorder and (d) the obstetric and neonatal outcome in this group of patients. Women with abnormal LFTs that delivered at our hospital over a 2-year period were identified from computerised hospital records and data was obtained from chart review. Forty-six out of a total of 13 181 (0.35%) women had liver disease diagnosed in pregnancy: Diagnoses included intrahepatic cholestasis of pregnancy (13), pre-eclampsia and the HELLP syndrome (eight), acute fatty liver of pregnancy (three), hyperemesis gravidarum (one), hepatitis C (13), B (four) and hepatitis A (one), cholelithiasis (two) and hepatitis of unknown aetiology (one). Symptoms at presentation were more predictive of the final diagnosis than the initial LFT profile. Investigation of the liver disorder was incomplete in 50% of cases. One mother required intensive care for 6 weeks postpartum and three others had significant postpartum haemorrhage. There was one neonatal death and 24 neonates were admitted to the special care baby unit. Eighteen women attended for their postnatal check up at 6 weeks. Eight of these women were referred to a hepatologist. Detection of liver disease in pregnancy identifies a group at risk of poor neonatal and maternal outcome. Structured guidelines should be implemented in obstetric units to facilitate appropriate investigation, treatment and referral patterns for these women.

Dexamethasone in the treatment of obstetric cholestasis: A case series

Twelve women with obstetric cholestasis were given dexamethasone after failure to respond to ursodeoxycholic acid. Clinical improvement was achieved in eight cases, without complete resolution of symptoms. Biochemical response was achieved in seven cases. All but two cases had good correlation between clinical and biochemical response. Women of Asian and South American origin were more likely to respond to dexamethasone than Caucasians. There were no reported maternal or fetal side-effects. However, the subsequent consequences of dexamethasone treatment for the mother and fetus have not been thoroughly evaluated. Therefore, even in Asian and South American women, larger studies of dexamethasone are required before this treatment can be recommended as a universally safe and effective treatment for obstetric cholestasis.

Intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disorder characterized by maternal pruritus in the third trimester, raised serum bile acids and increased rates of adverse fetal outcomes. The etiology of ICP is complex and not fully understood, but it is likely to result from the cholestatic effects of reproductive hormones and their metabolites in genetically susceptible women. Equally unclear are the mechanisms by which the fetal complications occur. This article reviews the epidemiology, clinical features, diagnosis, etiology and management of ICP.

The angiotensin-converting enzyme gene insertion–deletion polymorphism in a white British patient cohort with obstetric cholestasis

The DD genotype of the angiotensin-converting enzyme (ACE) gene is over-represented in Finnish patients with obstetric cholestasis (OC). The purpose of this study was to establish whether this genotype is associated with cholestasis in UK cases. In a retrospective case-control study, we determined the ACE insertion/deletion frequencies in 166 British cases and 100 control women by polymerase chain reaction analysis. No significant difference in allele frequencies was found between these groups, but allele frequencies differed significantly between Finnish and UK OC cases ( P = 0.0005). The prevalence of the DD genotype is lower in UK cases than in controls (χ2 [1 d.f.] = 4.32, P = 0.05) and the odds ratio for OC associated with the DD genotypeis 0.54, 95% confidence interval 0.30–0.97. In contrast to Finnish OC cases, the DD genotype of the ACE is not increased in UK cases.

A randomised placebo-controlled trial of prolonged prednisolone administration to patients with HELLP syndrome remote from term

OBJECTIVES

To evaluate the effect of prolonged administration of high-dose prednisolone on early onset HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome during expectant management.

STUDY DESIGN

A randomized, double-blind trial was performed in 31 pregnant women with HELLP syndrome with an onset before 30 weeks gestation. Patients received either 50mg prednisolone or placebo intravenously twice a day. Primary outcome measures were the entry-to-delivery interval and the number of recurrent HELLP exacerbations in the antepartum period.

RESULTS

Serious maternal morbidity was considerable, in particular in the placebo group where even on maternal occurred as a consequence of liver rupture. The mean entry-delivery interval did not differ between the prednisolone group (6.9 days) and the placebo group (8.0 days). However, patients in the prednisolone group had a significant lower risk of a recurrent HELLP exacerbation after the initial crisis had subsided, as compared to patients in the placebo group (HR 0.3, with 95% CI 0.3-0.9). Platelet count recovered faster in the prednisolone group as compared to the placebo group (mean 1.7 days versus 6.2 days, P<0.01).

CONCLUSIONS

HELLP syndrome remote from term causes high risk for serious maternal morbidity and mortality. When expectant management is pursued in selected patients with a HELLP syndrome remote from term, prolonged administration of prednisolone reduces the risk of recurrent HELLP syndrome exacerbations.

Plasma lipid profiles of women with intrahepatic cholestasis of pregnancy

OBJECTIVE

Intrahepatic cholestasis of pregnancy is associated with dyslipidemia, but the gestational lipid profile in relation to clinical diagnosis of the disease is unknown. The aim of this study was to undertake a detailed analysis of plasma lipids in women presenting with intrahepatic cholestasis of pregnancy and pruritus gravidarum.

METHODS

Plasma lipid concentrations were assessed in nonfasting blood samples from 63 women with intrahepatic cholestasis of pregnancy (n = 54, recruited at the time of diagnosis, and n = 9, who later developed the disease), 43 women with pruritus gravidarum, and 26 healthy pregnant controls during pregnancy and at 4-6 weeks postpartum.

RESULTS

Intrahepatic cholestasis of pregnancy was associated with an abnormal lipid profile. Low-density lipoprotein (LDL) cholesterol, apolipoprotein B-100, and total cholesterol concentrations were significantly raised during pregnancy in women with intrahepatic cholestasis of pregnancy compared with pruritus gravidarum and controls, and LDL-cholesterol was raised before clinical diagnosis. High-density lipoprotein cholesterol was lower in women with intrahepatic cholestasis of pregnancy compared with the pruritus gravidarum group. Ursodeoxycholic acid did not alter plasma lipid concentrations.

CONCLUSION

Intrahepatic cholestasis is associated with dyslipidemia, which may contribute to the pathogenesis of the disease. The elevation of LDL cholesterol and reduction of high-density lipoprotein cholesterol before clinical diagnosis may prove to be a useful biomarker for the early identification of intrahepatic cholestasis of pregnancy and differentiation from pruritus gravidarum.

LEVEL OF EVIDENCE

II-2.

Activity of hepatic enzymes from week sixteen of pregnancy

OBJECTIVE

This study was undertaken to determine the prevalence, epidemiology, and mother-child repercussions of increased alanine-aminotransferase levels from week 16 of pregnancy.

STUDY DESIGN

A longitudinal observational study of 381 pregnant women. The cause of increased alanine-aminotransferase levels during pregnancy and repercussions on the neonate were studied in 283 cases. Statistical analysis was performed with Mann-Whitney test, chi2 test, or the Fisher exact test.

RESULTS

The mean age of the mothers was 29.9 +/- 4.8 years. Twenty-five percent presented increased gamma-glutamyl-transpeptidase, alkaline phophatase, and dehydrogenase lactate from week 32. Increased alanine-aminotransferase was observed in 7.4% (95% CI, 5.00%-10.57%) of cases. Clinical disorders were light, transitory, and with no apparent cause, except for 1 hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome, 3 preeclampsias, and 1 gravidic cholestasis. No statistically significant differences were observed in the group of mother-child with alanine-aminotransferase normal or increased.

CONCLUSION

Most increases in alanine-aminotransferase from week 16 of pregnancy are transitory, non-specific, and have no repercussions on mother or child.

Routine investigations might be useful in pre-eclampsia, but not in gestational hypertension

BACKGROUND

Women referred to secondary care with suspected pregnancy-induced hypertension (PIH) are commonly investigated with blood tests and cardiotocography (CTG), regardless of the clinical severity of their condition. Over-investigation might lead to inappropriate intervention.

AIMS

To investigate how often abnormal blood test and CTG results occur in women with pre-eclampsia and gestational hypertension and in women who do not have pregnancy-induced hypertension.

METHODS

Retrospective case note review of 526 consecutive women referred with suspected pregnancy-induced hypertension to a district hospital. The frequency of abnormal test results and the pregnancy outcomes were analysed according to clinical classification.

RESULTS

36% of women referred did not meet the clinical criteria for a diagnosis of pregnancy-induced hypertension. Abnormalities of platelet count and/or liver function were seen in 11% of women with pre-eclampsia and in less than 2% of women with gestational hypertension and in a similar proportion of women who did not have pregnancy-induced hypertension. Gestational hypertension was associated with increased induction and caesarean birth rates, but not with low birthweight or preterm delivery. Progression from gestational hypertension to pre-eclampsia was not predicted by blood test abnormalities. Support for the routine use of antenatal CTG was not found.

CONCLUSIONS

A clinical diagnosis of pregnancy-induced hypertension should be confirmed before blood tests are ordered. The incidence of test abnormalities was only increased in pre-eclampsia and in gestational hypertension before term. CTG might only be of use in selected cases.

Glutathione S-transferase and liver function in intrahepatic cholestasis of pregnancy and pruritus gravidarum

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease associated with poor maternal and fetal outcome. The diagnosis is based on pruritus with abnormal liver function in the absence of other pathological conditions. However, pruritus in pregnancy is common, and it may be the only presenting feature in ICP. No reliable test currently exists that can discriminate between those women destined to develop ICP and those with the benign condition of pruritus gravidarum (PG). The purpose of this prospective study was to investigate longitudinally the serum concentration of glutathione S-transferase alpha (GSTA, a specific marker of hepatocellular integrity) and to compare this with the temporal profile of conventional liver function markers in women with ICP (n = 63), PG (n = 43), and normal pregnant controls (n = 26). Blood was sampled on at least 3 separate occasions between 16 weeks of gestation and 4 weeks postpartum. Serum concentrations of GSTA increased with gestation in ICP, being significantly higher from 24 (+/-2) weeks compared with controls (400% difference; 95% CI, 240%-734%; P < .001). GSTA was also higher in ICP versus PG (433% difference; 95% CI, 228%-790%; P < .001) throughout the gestational period studied. Significant differences in the ICP compared with control and PG groups were also found for total bile acids, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase and alkaline phosphatase. In conclusion, the measurement of GSTA provides a test of liver dysfunction that distinguishes women with ICP from those with PG. Additionally, on the basis of this study, reference ranges for biochemical markers of liver function require reevaluation in pregnancy.

Preeclampsia with abnormal liver function tests is associated with cholestasis in a subgroup of cases

OBJECTIVE

To investigate whether women with preeclampsia and abnormal liver function tests have raised serum bile acids.

DESIGN

Measurement of serum bile acids in serum specimens collected at the John Radcliffe Hospital, Oxford.

SETTING

Imperial College School of Medicine.

SAMPLE

Stored sera from 37 women with preeclampsia and abnormal liver function tests and from 19 controls.

METHODS

Enzymic total bile acid assay.

MAIN OUTCOME MEASURES

Total bile acid levels.

RESULTS

Women with preeclampsia and abnormal liver function tests had higher median bile acid levels than controls (5.7 vs. 3.2, p = 0.01). The reason for the raised median serum bile acid levels in the patient group is that three (8%) women with preeclampsia had markedly raised serum bile acids levels. There were no obvious clinical or biochemical features specific to these patients.

CONCLUSIONS

The pathological mechanisms causing hepatic impairment in some women with preeclampsia may predispose to cholestasis. As some women with preeclampsia and abnormal liver function complain of pruritus, we recommend checking the serum bile acids in this group of women. If these acids are raised the fetal prognosis may be adversely affected.

Clinical outcome in a series of cases of obstetric cholestasis identified via a patient support group

OBJECTIVE

To explore the clinical features of obstetric cholestasis pregnancies in UK white Caucasians.

DESIGN

A questionnaire survey.

SETTING

Study coordinated at Queen Charlotte's Hospital.

POPULATION

Clinical features of 352 affected pregnancies in 227 Caucasian women identified via a patient support group.

METHODS

Evaluation of the gestation at which prematurity and intrauterine death occur, and recording of additional clinical features in pregnancies complicated by obstetric cholestasis.

MAIN OUTCOME MEASURES

The timing of pregnancies complicated by intrauterine death and prematurity.

RESULTS

Among the affected pregnancies, 23 (7%) were complicated by intrauterine death (20 singletons and 3 twins) and 133 (38%) were delivered prematurely (56 spontaneous and 77 iatrogenic). Eighteen of the 20 singleton intrauterine deaths occurred after 37 weeks. All three intrauterine deaths in twin pregnancies occurred before 37 weeks. Pruritus started earlier in pregnancies complicated by spontaneous prematurity, but not in those complicated by intrauterine death.

CONCLUSIONS

Intrauterine death in singleton pregnancies complicated by obstetric cholestasis death mainly occurs after 37 weeks. The gestation at which pruritus is first reported may help to predict spontaneous prematurity.

Obstetric cholestasis, outcome with active management: a series of 70 cases

OBJECTIVE

To determine the nature and outcome of obstetric cholestasis in a United Kingdom population.

DESIGN

Prospective analysis of clinical outcome in women diagnosed with obstetric cholestasis that is actively managed.

SETTING

Antenatal population of three London hospitals between August 1999 and April 2001.

POPULATION

Seventy women with obstetric cholestasis defined as abnormal liver function (one or more abnormality in gamma-glutamyl transpeptidase, alanine amino-transferase, aspartate amino-transferase and total bile acids) in a pregnant woman with pruritus, in the absence of other pathology.

METHODS

All women were interviewed weekly regarding their symptoms. All were actively managed according to a standardised protocol, which included early delivery before 38 weeks. Obstetric outcome was recorded.

RESULTS

Seventy women of mean age 30 (6) years delivered 73 infants. The median gestation at onset of pruritus was 30 (range 4-39) weeks and at diagnosis of obstetric cholestasis was 33.7 (range 21-40.7) weeks. Asian women were more likely to be diagnosed with obstetric cholestasis. Pruritus was usually severe and generalised, and commonly worst on the palms and/or soles of the feet. There were no stillbirths or perinatal deaths. Twenty-five women required caesarean section (36%); only four (16%) were for fetal distress. Twelve women (17%) delivered before 37 weeks, of which eight (67%) were iatrogenic. Ten (14%) infants required admission to the special care baby unit of which four (40%) were ventilated.

CONCLUSIONS

Policies of active management result in increased intervention and associated complications. This must be balanced against possible reductions in perinatal mortality.

Pruritus may precede abnormal liver function tests in pregnant women with obstetric cholestasis: a longitudinal analysis

Obstetric cholestasis is a liver disorder unique to pregnancy, which typically presents with pruritus. However, pruritus is common in pregnancy and the diagnosis of obstetric cholestasis is confirmed by finding abnormal liver function. We report 10 cases in which pruritus occurred before any abnormality in liver function tests (including total serum bile acids) and discuss the implications of this for clinical practice.

Gamma glutamyl transferase

Serum gamma-glutamyl transferase (GGT) has been widely used as an index of liver dysfunction and marker of alcohol intake. The last few years have seen improvements in these areas and advances in understanding of its physiological role in counteracting oxidative stress by breaking down extracellular glutathione and making its component amino acids available to the cells. Conditions that increase serum GGT, such as obstructive liver disease, high alcohol consumption, and use of enzyme-inducing drugs, lead to increased free radical production and the threat of glutathione depletion. However, the products of the GGT reaction may themselves lead to increased free radical production, particularly in the presence of iron. There have also been important advances in the definition of the associations between serum GGT and risk of coronary heart disease, Type 2 diabetes, and stroke. People with high serum GGT have higher mortality, partly because of the association between GGT and other risk factors and partly because GGT is an independent predictor of risk. This review aims to summarize the knowledge about GGT's clinical applications, to present information on its physiological roles, consider the results of epidemiological studies, and assess how far these separate areas can be combined into an integrated view.

Management and monitoring of severe preeclampsia

Preeclampsia is associated with increased maternal and perinatal morbidity and mortality. Preeclampsia is more than pregnancy-induced hypertension. The hypertension is only one manifestation of an underlying multifactorial, multisystem disorder, initiated early in pregnancy. In established severe disease there is volume contraction, reduced cardiac output, enhanced vascular reactivity, increased vascular permeability and platelet consumption. Medical treatment of severe hypertension in pregnancy is required. The more controversial issues are the role of pharmacological treatment in conservative management of severe preeclampsia aiming at prolongation of pregnancy, the ability of such therapy to modify the course of the underlying systemic disorder and the effects on fetal and maternal outcome. This paper presents an overview concerning the current developments in management and monitoring of severe preeclampsia. Controversial topics such as the role of plasma volume expansion in preeclampsia, expectant versus aggressive management of severe preeclampsia remote from term, and pharmacological interventions in the management of eclampsia and the HELLP syndrome are addressed.