Fatty liver in pregnancy: a narrative review of two distinct conditions

Risk Factors Related to the Development of Nonalcoholic Fatty Liver: A Systematic Review

Background: Nonalcoholic fatty liver disease (NAFLD) has a major impact on public health owing to its high morbidity and mortality due to its close relationship with several conditions, including metabolic syndrome, cirrhosis, and cancer. Therefore, this review aimed to systematically compile and summarize the scientific literature on early risk factors for NAFLD development. Methods: A systematic review of population-based cohort studies was conducted. Studies reporting the risk factors associated with nonalcoholic steatohepatitis (NASH) and NAFLD were screened. Results: The search yielded 987 unique records, of which 196 articles were selected after title and abstract screening. A total of 39 articles were read in full text after quality analysis using Downs and Black criteria; 10 of the studies were excluded due to heterogeneity or inconclusive results. Finally, 30 publications were included in this systematic review. The review revealed that clinical conditions such as obesity, weight change, psoriasis, polycystic ovary syndrome, diabetes, thyroid disorders, and elevated serum uric acid levels increase the risk of developing nonalcoholic fatty liver. In addition, lifestyle factors such as sedentary behavior, active or passive smoking, poor sleep quality, and consumption of carbonated beverages are associated with this condition. Conclusions: Evidence was found on the association between different clinical and lifestyle risk factors and NAFLD. This supports the need for preventive, diagnostic, and therapeutic strategies to improve the metabolic, hepatic, and oncological outcomes related to this condition.

Association between the atherogenic index of plasma and non-alcoholic fatty liver disease in Korean pregnant women: secondary analysis of a prospective cohort study

Background

Recent studies have shown an association between atherogenic index of plasma (AIP) and nonalcoholic fatty liver disease (NAFLD), but the association in a population of pregnant women remains unclear.

Objectives

Our study aimed to examine the association between AIP and NAFLD in pregnant Korean women.

Methods

Our study used publicly available data from Korea, which recruited singleton pregnant women between November 2014 and September 2016 who were at 10-14 weeks of gestation. The presence of NAFLD was diagnosed by liver ultrasound. AIP was calculated as log10 (TG/HDL). Participants were grouped according to AIP tertile: T1 (< 0.16, n = 195), T2 (0.16-0.32, n = 195), and T3 (>0.32, n = 196). Logistic regression models were used to estimate the relationship between AIP and NAFLD. Subgroup and sensitivity analyses were conducted to explore the stability of this relationship. Restricted cubic spline (RCS) curve fitting was employed to investigate potential non-linear associations.

Results

After excluding data on missing variables, 586 singleton pregnant women were finally included. The subjects included in the study had an average AIP of 0.22 (0.11, 0.37), and NAFLD occurred in 110 (18.8%) pregnant women. We observed a positive linear association between AIP and NAFLD (OR = 1.33, 95% CI: 1.19-1.48), which persisted after adjusting for potential confounders (OR = 1.2, 95% CI: 1.06-1.37). When AIP was used as a categorical variable, after adjusting for covariates, the NAFLD risk was significantly higher in the highest tertile of AIP than in the lowest group (OR = 2.02, 95% CI: 1.11-3.68). Their correlations were stable across subgroups and sensitivity analyses.

Conclusion

In this secondary analysis of a prospective cohort study of pregnant Korean women, AIP was found to be positively associated with NAFLD. These outcomes might be used to screen for NAFLD in pregnant women.

Maternal obesity and metabolic (dysfunction) associated fatty liver disease in pregnancy: a comprehensive narrative review

INTRODUCTION

Obesity and metabolic-associated fatty liver disease (MAFLD) during pregnancy constitute significant problems for routine antenatal care, with increasing prevalence globally. Similar to obesity, MAFLD is associated with a higher risk for maternal complications (e.g. pre-eclampsia and gestational diabetes) and long-term adverse health outcomes for the offspring. However, MAFLD during pregnancy is often under-recognized, with limited management/treatment options.

AREAS COVERED

PubMed/MEDLINE, EMBASE, and Scopus were searched based on a search strategy for obesity and/or MAFLD in pregnancy to identify relevant papers up to 2024. This review summarizes the pertinent evidence on the relationship between maternal obesity and MAFLD during pregnancy. Key mechanisms implicated in the underlying pathophysiology linking obesity and MAFLD during pregnancy (e.g. insulin resistance and dysregulated adipokine secretion) are highlighted. Moreover, a diagnostic approach for MAFLD diagnosis during pregnancy and its complications are presented. Finally, promising relevant areas for future research are covered.

EXPERT OPINION

Research progress regarding maternal obesity, MAFLD, and their impact on maternal and fetal/offspring health is expected to improve the relevant diagnostic methods and lead to novel treatments. Thus, routine practice could apply more personalized management strategies, incorporating individualized algorithms with genetic and/or multi-biomarker profiling to guide prevention, early diagnosis, and treatment.

Features of the course of non-alcoholic fatty liver disease in women at different age periods: literature review

The review examines the epidemiology and risk factors of non-alcoholic fatty liver disease (NAFLD) for women. According to various sources, the global prevalence of NAFLD ranges from 20 to 40% of the adult population in the world. In Russia, 37.3% of polyclinic patients have NAFLD. NAFLD can occur at any age and has differences in prevalence and severity depending on ethnicity and gender. Over the past 10 years, there has been a trend towards an increase in the prevalence of NAFLD among women, as well as a sharper increase in mortality compared to men. Regardless of gender, prognostically significant risk factors for NAFLD include age, obesity, type 2 diabetes mellitus, insulin resistance, dyslipidemia. The clinical course and prognosis of NAFLD in women depends on age, reproductive stage and use of synthetic hormones. Premenopausal women have less pronounced liver fibrosis and a better life prognosis compared to postmenopausal men and women. The article describes the features of the course of NAFLD in the reproductive period, pre- and postmenopausal period, characterizes the effect of liver steatosis on the course and outcome of pregnancy, the perinatal condition of the mother and fetus. Thus, there are gender differences in the prevalence, risk factors, fibrosis, and clinical outcomes of NAFLD. The prevalence and severity of NAFLD in reproductive age is higher in men, but after menopause, there is an increase in this pathology in women, especially those with metabolic disorders. Liver steatosis can affect the course of pregnancy, labor and postpartum periods.

Obesogenic Diet in Mice Leads to Inflammation and Oxidative Stress in the Mother in Association with Sex-Specific Changes in Fetal Development, Inflammatory Markers and Placental Transcriptome

BACKGROUND

Obesity during pregnancy is related to adverse maternal and neonatal outcomes. Factors involved in these outcomes may include increased maternal insulin resistance, inflammation, oxidative stress, and nutrient mishandling. The placenta is the primary determinant of fetal outcomes, and its function can be impacted by maternal obesity. The aim of this study on mice was to determine the effect of obesity on maternal lipid handling, inflammatory and redox state, and placental oxidative stress, inflammatory signaling, and gene expression relative to female and male fetal growth.

METHODS

Female mice were fed control or obesogenic high-fat/high-sugar diet (HFHS) from 9 weeks prior to, and during, pregnancy. On day 18.5 of pregnancy, maternal plasma, and liver, placenta, and fetal serum were collected to examine the immune and redox states. The placental labyrinth zone (Lz) was dissected for RNA-sequencing analysis of gene expression changes.

RESULTS

the HFHS diet induced, in the dams, hepatic steatosis, oxidative stress (reduced catalase, elevated protein oxidation) and the activation of pro-inflammatory pathways (p38-MAPK), along with imbalanced circulating cytokine concentrations (increased IL-6 and decreased IL-5 and IL-17A). HFHS fetuses were asymmetrically growth-restricted, showing sex-specific changes in circulating cytokines (GM-CSF, TNF-α, IL-6 and IFN-γ). The morphology of the placenta Lz was modified by an HFHS diet, in association with sex-specific alterations in the expression of genes and proteins implicated in oxidative stress, inflammation, and stress signaling. Placental gene expression changes were comparable to that seen in models of intrauterine inflammation and were related to a transcriptional network involving transcription factors, LYL1 and PLAG1.

CONCLUSION

This study shows that fetal growth restriction with maternal obesity is related to elevated oxidative stress, inflammatory pathways, and sex-specific placental changes. Our data are important, given the marked consequences and the rising rates of obesity worldwide.

Bile acids metabolism in the gut-liver axis mediates liver injury during lactation

AIMS

The obesity epidemic, especially in pregnant women, linked to a higher risk of liver diseases. Bile acids (BAs) are known to participate in liver metabolism, but this function during obesogenic reproductive process remains largely uncertain. The study aims to identify whether a high-fat diet (HFD) during pregnancy negatively disturbs liver metabolism and the potential role of BAs and gut microbiota (GM)in a sow model.

MAIN METHODS

Reproductive (RP) or non-reproductive (NRP) sows were fed a 15 % HFD containing compound oil. Body condition, blood parameters, and BAs levels/profile during gestation and lactation were monitored. The tissues and colonic GM were collected after euthanasia at the end of lactation. HepG2 hepatocytes were used to test the effects of BAs on liver damage and the mechanism.

KEY FINDINGS

Reproductive sows fed an HFD (HF-RP) experienced increased weight loss, and elevated plasma non-esterified fatty acid (NEFA) during lactation, consistent with exacerbated lipolysis, aggravating the risk of liver damage. HF-RP sows exhibited an enlarged BAs pool size and alterations in composition (higher levels of CDCA and LCA species) along with a drastic change in the GM (increased Firmicutes/Bacteroidetes ratio and declined Lactobacillus abundance). Furthermore, the liver FXR-SHP pathway, BAs synthesis and transport underwent adaptive regulation to sustain the BAs homeostasis and hepatic lipid metabolism. CDCA alleviated endoplasmic reticulum (ER) stress induced by palmitic acid via FXR pathway, in HepG2 cells.

SIGNIFICANCE

Lactation BAs metabolism signal in gut-liver axis coordinated the risk of liver damage induced by exacerbated lipolysis in obesogenic pregnancy.

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.

Hepatoprotective agents in the management of intrahepatic cholestasis of pregnancy: current knowledge and prospects

Intrahepatic cholestasis of pregnancy (ICP) is characterized by unexplained distressing pruritus in the mother and poses significant risk to the fetus of perinatal mortality. Occurring in the second and third trimester, the serum bile acid and aminotransferase are usually elevated in ICP patients. Ursodeoxycholic acid (UDCA) is the first line drug for ICP but the effectiveness for hepatoprotection is to a certain extent. In ICP patients with severe liver damage, combination use of hepatoprotective agents with UDCA is not uncommon. Herein, we reviewed the current clinical evidence on application of hepatoprotective agents in ICP patients. The underlying physiological mechanisms and their therapeutic effect in clinical practice are summarized. The basic pharmacologic functions of these hepatoprotective medications include detoxification, anti-inflammation, antioxidation and hepatocyte membrane protection. These hepatoprotective agents have versatile therapeutic effects including anti-inflammation, antioxidative stress, elimination of free radicals, anti-steatohepatitis, anti-fibrosis and anti-cirrhosis. They are widely used in hepatitis, non-alcoholic fatty liver disease, drug induced liver injury and cholestasis. Evidence from limited clinical data in ICP patients demonstrate reliable effectiveness and safety of these medications. Currently there is still no consensus on the application of hepatoprotective agents in ICP pregnancies. Dynamic monitoring of liver biochemical parameters and fetal condition is still the key recommendation in the management of ICP pregnancies.

Utility of Doppler-Ultrasound and Liver Elastography in the Evaluation of Patients with Suspected Pregnancy-Related Liver Disease

Grayscale abdomen ultrasound (US) is routinely performed in pregnant women with suspected pregnancy-related liver dysfunction, but its diagnostic yield is very low. We aimed to investigate the association between Doppler-US findings, liver stiffness measurement (LSM) and different causes of pregnancy-related liver dysfunction. This is a prospective cohort study of pregnant women referred to our tertiary center for any suspected gastrointestinal disease between 2017 and 2019 and undergoing Doppler-US and liver elastography. Patients with previous liver disease were excluded from the analysis. For group comparisons of categorical and continuous variables, the chi-square test or Mann-Whitney test, and the McNemar test were used, as appropriate. A total of 112 patients were included in the final analysis, of whom 41 (36.6%) presented with suspected liver disease: 23 intrahepatic cholestasis of pregnancy (ICP), six with gestational hypertensive disorders and 12 cases with undetermined causes of elevated liver enzymes. Values of LSM were higher and significantly associated with a diagnosis of gestational hypertensive disorder (AUROC = 0.815). No significant differences at Doppler-US or LSM were found between ICP patients and controls. Patients with undetermined causes of hypertransaminasemia showed higher hepatic and splenic resistive indexes than controls, suggesting splanchnic congestion. The evaluation of Doppler-US and liver elastography is clinically useful in patients with suspected liver dysfunction during pregnancy. Liver stiffness represents a promising non-invasive tool for the assessment of patients with gestational hypertensive disorders.

Obesogenic diet in mice compromises maternal metabolic physiology and lactation ability leading to reductions in neonatal viability

AIMS

Diets containing high-fat and high sugar (HFHS) lead to overweight/obesity. Overweight/obesity increases the risk of infertility, and of the pregnant mother and her child for developing metabolic conditions. Overweight/obesity has been recreated in mice, but most studies focus on the effects of chronic, long-term HFHS diet exposure. Here, we exposed mice to HFHS from 3 weeks prior to pregnancy with the aim of determining impacts on fertility, and gestational and neonatal outcomes.

METHODS

Time-domain NMR scanning was used to assess adiposity, glucose, and insulin tolerance tests were employed to examine metabolic physiology, and morphological and proteomic analyses conducted to assess structure and nutrient levels of maternal organs and placenta.

RESULTS

Fertility measures of HFHS dams were largely the same as controls. HFHS dams had increased adiposity pre-pregnancy, however, exhibited exacerbated lipolysis/hyper-mobilization of adipose stores in late pregnancy. While there were no differences in glucose or insulin tolerance, HFHS dams were hyperglycemic and hyperinsulinemic in pregnancy. HFHS dams had fatty livers and altered pancreatic islet morphology. Although fetuses were hyperglycemic and hyperinsulinemic, there was no change in fetal growth in HFHS dams. There were also reductions in placenta formation. Moreover, there was increased offspring loss during lactation, which was related to aberrant mammary gland development and milk protein composition in HFHS dams.

CONCLUSIONS

These findings are relevant given current dietary habits and the development of maternal and offspring alterations in the absence of an increase in maternal weight and adiposity during pregnancy, which are the current clinical markers to determine risk across gestation.

Application of CEEMD noise reduction algorithm in ultrasound imaging in evaluating fetuses with abnormal glucose metabolism in late pregnancy

Objectives:

To explore the predictive effect of abnormal glucose metabolism and fetal hemodynamic parameters on adverse pregnancy outcome.

Methods:

One hundred and nine pregnant women with abnormal glucose metabolism during pregnancy from June 2016 to October 2018 were selected and divided into poor prognosis group (34 cases) and good prognosis group (75 cases). The hemodynamic parameters of fetal cerebral artery (MCA), umbilical artery (UA) and uterine artery of pregnancy (UT-A), including peak systolic velocity (s / D), resistance index (RI) and plasticity index (PI), were measured by color Doppler ultrasound. The receiver operating characteristic (ROC) curve of adverse pregnancy outcomes was drawn and the best threshold index was determined.

Results:

MCA-PI poor prognosis group, MCA-RI, RI ratio (MCA/UA) are lower than the good prognosis group, Ut-A-PI is higher than the good prognosis group (P<0.05,). ROC curve analysis results show that when the MCA-PI 1.56, the sensitivity of the predicted adverse outcomes of pregnancy, the highest specificity<, was 91.18%, 80.00%, respectively. Logistic regression analysis of risk factors shows poor pregnancy outcomes include: pregnant women, older age, body mass index ≥24.0kg/m2 and a family history of diabetes. Protective factors include exercise during pregnancy, MCA-PI≥1.56, MCA-RI≥0.63 and RI The ratio (MCA/UA) ≥0.84.

Conclusion:

Color Doppler ultrasound measured MCA-PI<1.56 the most important indicators of poor pregnancy outcomes as abnormal glucose metabolism during pregnancy and predict the exact cutoff. Pregnant women, older age, body mass index ≥24.0kg/m2 and a family history of diabetes and abnormal glucose metabolism during pregnancy risk factors for adverse outcomes of pregnancy.

Prenatal Noninvasive Trio-WES in a Case of Pregnancy-Related Liver Disorder

Liver disease in pregnancy may present as an acute condition related to the gestational period, characterized by pruritus, jaundice, and abnormal liver function. The disease may be misdiagnosed with other liver diseases, some of which may have consequences for fetal health. It is therefore advisable to implement rapid diagnostic strategies to provide information for the management of pregnancy in these conditions. We report the case of a healthy woman with a twin pregnancy from homologous in vitro fertilization (IVF), who in the third trimester presented jaundice and malaise. Biochemical investigations and liver hyperechogenicity raised the suspicion of acute fatty liver disease of pregnancy (AFLP). Non-invasive prenatal whole-exome sequencing (WES) in the trio identified the Phe305Ile heterozygous variant in the ATP8B1 gene. Considering the twin pregnancy, the percentage of the variant versus the wild allele was of 31%, suggesting heterozygosity present in the mother alone. This analysis showed that the mother was affected by benign recurrent intrahepatic cholestasis of pregnancy (ICP1: # 147480) and indicated the opportunity to anticipate childbirth to avoid worsening of the mother’s health. WES after the birth of the twins confirmed the molecular data.

Non-alcoholic fatty liver disease: A patient guideline

This patient guideline is intended for all patients at risk of or living with non-alcoholic fatty liver disease (NAFLD). NAFLD is the most frequent chronic liver disease worldwide and comes with a high disease burden. Yet, there is a lot of unawareness. Furthermore, many aspects of the disease are still to be unravelled, which has an important impact on the information that is given (or not) to patients. Its management requires a close interaction between patients and their many healthcare providers. It is important for patients to develop a full understanding of NAFLD in order to enable them to take an active role in their disease management. This guide summarises the current knowledge relevant to NAFLD and its management. It has been developed by patients, patient representatives, clinicians and scientists and is based on current scientific recommendations, intended to support patients in making informed decisions.

Impact of Maternal Obesity on the Metabolism and Bioavailability of Polyunsaturated Fatty Acids during Pregnancy and Breastfeeding

Prenatal and postnatal development are closely related to healthy maternal conditions that allow for the provision of all nutritional requirements to the offspring. In this regard, an appropriate supply of fatty acids (FA), mainly n-3 and n-6 long-chain polyunsaturated fatty acids (LCPUFA), is crucial to ensure a normal development, because they are an integral part of cell membranes and participate in the synthesis of bioactive molecules that regulate multiple signaling pathways. On the other hand, maternal obesity and excessive gestational weight gain affect FA supply to the fetus and neonate, altering placental nutrient transfer, as well as the production and composition of breast milk during lactation. In this regard, maternal obesity modifies FA profile, resulting in low n-3 and elevated n-6 PUFA levels in maternal and fetal circulation during pregnancy, as well as in breast milk during lactation. These modifications are associated with a pro-inflammatory state and oxidative stress with short and long-term consequences in different organs of the fetus and neonate, including in the liver, brain, skeletal muscle, and adipose tissue. Altogether, these changes confer to the offspring a higher risk of developing obesity and its complications, as well as neuropsychiatric disorders, asthma, and cancer. Considering the consequences of an abnormal FA supply to offspring induced by maternal obesity, we aimed to review the effects of obesity on the metabolism and bioavailability of FA during pregnancy and breastfeeding, with an emphasis on LCPUFA homeostasis.