Second trimester amniotic fluid retinol in patients developing preeclampsia

Is salivary uric acid, a putative biomarker of pre-eclampsia, of maternal, placental, or fetal origin?

OBJECTIVES

Increased salivary uric acid (sUA) represents a potential biomarker predictive of pre-eclampsia (PE), but its origin is unclear. The study explores whether sUA levels reflect maternal or feto-placental physiological stress and whether sUA levels in these cases correlate with amniotic fluid (fetal origin), maternal blood (maternal origin), or cord blood (fetal vs placental origin).

STUDY DESIGN

Pregnant women (n = 39) undergoing amniotomy or caesarean section after 34 gestational weeks were designated into three groups of either maternal, feto-placental, or no signs of physiological stress: women (n = 15) in the established first phase of active labour and without any signs of fetal growth restriction (FGR) or PE were assigned to the maternal stress group, women (n = 6) with an ultrasound-based diagnosis of FGR, with or without PE, were assigned to the feto-placental stress group, and women (n = 18) not yet in active labour and without any signs of FGR or PE, were assigned to the control group. Uric acid levels in corresponding samples of amniotic fluid, saliva, maternal blood, and cord blood were compared between groups and between body compartments within each group.

RESULTS

The feto-placental stress group showed increased UA levels in saliva (median, interquartile range [IQR]: 0.47 [0.38] mmol/L, P = 0.023) and maternal blood (0.42 [0.13] mmol/L, P = 0.032), but no differences in amniotic fluid or cord blood compared with the other groups. Within the control and maternal stress group, sUA levels were lower compared with maternal blood (0.20 [0.08] vs 0.25 [0.08] mmol/L, Pcontrol = 0.018; 0.20 [0.06] vs 0.26 [0.08] mmol/L, Pmaternal = 0.001) and highest in amniotic fluid (control group (0.49 [0.18] mmol/L): Pmaternal,blood = 0.001, Pumbilical,artery = <0.001, Pumbilical,vein = <0.001, Psaliva = <0.001) (maternal stress group (0.56 [0.23] mmol/L): Pmaternal,blood = 0.021, Pumbilical,artery = 0.006, Pumbilical,vein = 0.004, Psaliva = 0.003). Levels did not differ between compartments in the feto-placental stress group.

CONCLUSIONS

Salivary and maternal blood UA levels were increased in the feto-placental stress group with salivary levels increasing more than blood levels compared with the maternal stress and control groups, whilst UA in amniotic fluid were not different between the groups, suggesting a placental origin and potential use of sUA as a biomarker of placental dysfunction, including FGR and severe PE.

STRA6 and Placental Retinoid Metabolism in Gestational Diabetes Mellitus

BACKGROUND

Recent reports indicate the potential role of the stimulated by retinoic acid 6 (STRA6) protein in developing insulin resistance. The study's objective was to assess placental STRA6 expression and staining pattern in human pregnancy complicated by gestational diabetes mellitus (GDM). The expression pattern of further relevant genes involved in retinoid metabolism was also evaluated.

METHODS

A retrospective case-control study on paraffin-embedded placental tissue. Twenty-two human pregnancies affected by GDM, namely, 11 insulin-treated (iGDM) and 11 diet-controlled (dGDM), were compared with 22 normal-developed pregnancies (controls). An RT-PCR was performed in a random sample of 18 patients (six iGDM, six dGDM, and six controls) to assess RNA expression of STRA6 and further markers of retinoid metabolism. A semi-quantitative intensity evaluation at immunohistochemistry was performed for STRA6 in all 44 recruited patients.

RESULTS

STRA6 showed a decreased placental staining (9.09% vs. 68.18% positively stained samples, p < 0.05) and augmented RNA expression in dGDM patients than controls (ΔCT expression 0.473, IQR 0.403-0.566 vs. 0.149, IQR 0.092-0.276, p < 0.05). The protein staining pattern in patients affected by iGDM was comparable to controls. A reduced RNA expression of LPL, LRP1, VLDLR, and MTTP besides an augmented expression of LDLR was found in dGDM, while overexpression of LRP1 and LPL was found in iGDM patients. Unlike in the control group, significant positive correlations were found between RXRα and the proteins involved in the intracellular uptake of ROH, such as STRA6, LRP1, LRP2, and VLDLR.

CONCLUSIONS

An altered placental expression and staining pattern of STRA6 were found in pregnancies complicated by GDM compared to the controls. These changes were coupled to an altered expression pattern of several other genes involved in the retinoid metabolism.

Is Glycated Hemoglobin A1c Level Associated with Adverse Pregnancy Outcomes of Women Affected by Pre-Gestational Diabetes?

Background and Objectives: This observational study aims to determine the correlation between glycemic control with the HbA1c value and adverse obstetric outcome in women affected by pre-gestational diabetes. Materials and Methods: A retrospective analysis has been performed at the University Hospital of Udine. Only patients with a singleton pregnancy, pre-gestational diabetes, and known level of Hb A1c throughout pregnancy were included in the study. Results: According to the HbA1c level, at the beginning of pregnancy, 49 patients with HbA1c ≤ 7.0% were compared with 45 patients with HbA1c > 7.0%. Maternal age at diagnosis of the disease was significantly higher in the group with HbA1c ≤ 7% than in the group with HbA1c > 7%, 26.00 (18.00–32.00) vs. 20.00 (12.50–27.00). Women with HbA1c ≤ 7.0% reached, at term of pregnancy, significantly lower levels of HbA1c, 5.8% (5.7–6.0) vs. 6.7% (6.3–7.3). Daily insulin units were statistically different between the two groups at the end of pregnancy (47.92 (39.00–67.30) vs. 64.00 (48.00–82.00)). Proteinuria was significantly higher in the group with HbA1c > 7.0%, who delivered at earlier gestational age (37.57 (35.57–38.00) vs. 38.14 (38.00–38.43). Moreover, women with HbA1c > 7.0% had a significantly higher prevalence of an adverse composite outcome. Of note, in multivariate logistic regression analysis, pregnancy complications were significantly correlated to pre-pregnancy HbA1c > 7.0% (OR 2.95 CI.95 1.16–7.48, p < 0.05) independently of age, insulin treatment, and type of diabetes. Conclusions: Our data, obtained from a single-center cohort study, suggest that starting pregnancy with poor glycemic control might predict more complex management of diabetes in the following trimesters.

Biosensors for Detection of Human Placental Pathologies: A Review of Emerging Technologies and Current Trends

Substantial growth in the biosensor research has enabled novel, sensitive and point-of-care diagnosis of human diseases in the last decade. This paper presents an overview of the research in the field of biosensors that can potentially predict and diagnosis of common placental pathologies. A survey of biomarkers in maternal circulation and their characterization methods is presented, including markers of oxidative stress, angiogenic factors, placental debris, and inflammatory biomarkers that are associated with various pathophysiological processes in the context of pregnancy complications. Novel biosensors enabled by microfluidics technology and nanomaterials is then reviewed. Representative designs of plasmonic and electrochemical biosensors for highly sensitive and multiplexed detection of biomarkers, as well as on-chip sample preparation and sensing for automatic biomarker detection are illustrated. New trends in organ-on-a-chip based placental disease models are highlighted to illustrate the capability of these in vitro disease models in better understanding the complex pathophysiological processes, including mass transfer across the placental barrier, oxidative stress, inflammation, and malaria infection. Biosensor technologies that can be potentially embedded in the placental models for real time, label-free monitoring of these processes and events are suggested. Merger of cell culture in microfluidics and biosensing can provide significant potential for new developments in advanced placental models, and tools for diagnosis, drug screening and efficacy testing.

New LC-MS/MS method with single-step pretreatment analyzes fat-soluble vitamins in plasma and amniotic fluid

Fat-soluble vitamins (FSVs), A, D, and E, are components of prenatal vitamin care. Previously, limited evidence existed to explain on a molecular level how maternal FSV supplementation affects the fetus during pregnancy. We developed a simplified LC-MS/MS method to simultaneously detect FSVs in maternal plasma (MP) and amniotic fluid (AF); we used this approach to investigate the correlation between FSV levels in these two matrices. With this method, we circumvented frequently used liquid-liquid extraction or solid-phase extraction methods and, instead, used simple protein precipitation with acetonitrile for sample preparation. This method displayed satisfactory linearity, intra- and inter-day imprecision, and accuracy. We validated the consistency with standard reference material 972a and 968f certification. In analysis of MP and AF samples from 50 pregnant women in the second trimester, concentrations of retinol, 25-hydroxyvitamin D3 [25(OH)D3], and α-tocopherol (reflecting vitamins A, D, and E, respectively) were lower in AF than in MP. Significant positive correlations existed between MP and AF for 25(OH)D3 (r = 0.667; P < 0.001) and retinol (r = 0.393; P = 0.005), but not for α-tocopherol (r = 0.145, P > 0.05). This novel LC-MS/MS method shows prominent applicability for FSV detection and the observed correlations contribute to research on fetal development.

Biomarkers of oxidative stress in pregnancy complications

Pregnancy complications including pre-eclampsia, gestational-diabetes mellitus, preterm birth and intrauterine growth restriction can cause acute and chronic health problems for the mother and lead to fetal loss or dysregulation of infant physiology. The human placenta is susceptible to oxidative stress and oxidative damage in early gestation contributes to the onset of these conditions later in pregnancy. Current methods of predicting pregnancy complications are limited and although a large number of factors are associated with disease progression, few biomarkers have been used to aid in disease diagnosis early in gestation. This review discusses the detection of oxidative stress markers in biological fluids and highlights the need for further studies to validate their use in the prediction or diagnosis of pregnancy disorders.

First trimester concentrations of the TTR-RBP4-retinol complex components as early markers of insulin-treated gestational diabetes mellitus

BACKGROUND

The objective of the study was to investigate the relationship between first trimester maternal serum levels of the TTR-RBP4-ROH complex components and the later insurgence of an altered glucose metabolism during pregnancy.

METHODS

Retrospective case control study including 96 patients between the 12th and 14th week of gestation, 32 that developed gestational diabetes mellitus (GDM), respectively, 21 non-insulin-treated (dGDM) and 11 insulin-treated (iGDM), 20 large for gestational age fetuses (LGA) without GDM and 44 patients with normal outcome as control. Serum concentrations of RBP4 and TTR were assessed by ELISA; serum concentration of ROH by reverse-phase high performance liquid chromatography (rpHPLC). The molecular heterogeneity of TTR and RBP4 was analyzed after immunoprecipitation by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS).

RESULTS

iGDM patients were characterized by reduced TTR, RBP4 and ROH compared to controls (respectively, iGDM vs. controls, mean±SD: TTR 3.96±0.89 μmol/L vs. 4.68±1.21 μmol/L, RBP4 1.13±0.25 μmol/L vs. 1.33±0.38 μmol/L and ROH 1.33±0.17 μmol/L vs. 1.62±0.29 μmol/L, p<0.05). TTR containing Gly10 in place of Cys10 was lower in the iGDM group (p<0.05) compared to controls. In the final logistic regression model ROH significantly predicted the diagnosis of iGDM (OR 0.93, 95% CI 0.87-0.98, p<0.05).

CONCLUSIONS

First trimester maternal serum ROH, RBP4 and TTR represent potential biomarkers associated with the development of iGDM.