Placental morphometry in hypertensive disorders of pregnancy and its relationship with birth weight in a Latin American population

A longitudinal and cross-sectional study of placental circulation between normal and placental insufficiency pregnancies

INTRODUCTION

To longitudinally and cross-sectionally study the differences in the uterine artery pulsatility index (UTPI), umbilical artery pulsatility index (UAPI) and placental vascularization indices (PVIs, derived from 3-dimensional power Doppler) between normal and placental insufficiency pregnancies throughout gestation.

METHODS

UTPI, UAPI and PVI were measured 6 times at 4- to 5- week intervals from 11 to 13+6 weeks-36 weeks. Preeclampsia (PE) and fetal growth restriction (FGR) were defined as placental insufficiency. Comparisons of UTPI, UAPI and PVI between normal and insufficiency groups were performed by one-way repeated measures analysis of variance.

RESULTS

A total of 125 women were included: monitored regularly from the first trimester to 36 weeks of gestation: 109 with normal pregnancies and 16 with placental insufficiency. Longitudinal study of the normal pregnancy group showed that UTPI and UAPI decreased significantly every 4 weeks, while PVIs increased significantly every 8 weeks until term. In the placental insufficiency group however, this decrease occurred slower at 8 weeks intervals and UTPI stabilized after 24 weeks. No significant difference was noted in PVIs throughout pregnancy. Cross-sectional study from different stages of gestation showed that UTPI was higher in the insufficiency group from 15 weeks onward and PVIs were lower after 32 weeks.

DISCUSSION

Compared to high-risk pregnancies with normal outcome, UTPI and UAPI needed a longer time to reach a significant change in those with clinical confirmation of placental insufficiency pregnancies and no significant change was found in PVI throughout gestation. UTPI was the earliest factor in detecting adverse outcome pregnancies.

FGR-associated placental insufficiency and capillary angiogenesis involves disruptions in human placental miRNAs and mRNAs

Fetal growth restriction (FGR) is one of the most common pregnancy complications culminating in adverse fetal outcome, including preterm birth, neonatal mortality and stillbirth. Compromised placental development and function, especially disruption in angiogenesis and inadequate nutrient supply are contributing factors. Fetal sex also influences placental function. Knowledge of gene expression changes and epigenetic factors contributing to placental dysfunction in FGR pregnancies will help identify biomarkers and help target interventions. This study tested the hypothesis that FGR pregnancies are associated with disruptions in miRNA - an epigenetic factor and mRNAs involving key mediators of angiogenesis and microvessel development. Changes in expression of key genes/proteins involved in placental dysfunction by RT-PCR and immunohistochemistry and miRNA changes by RNA sequencing were undertaken with term placenta from 12 control and 20 FGR pregnancies. Findings showed changes in expression of genes involved in steroidogenesis, steroid action, IGF family members, inflammatory cytokines and angiogenic factors in FGR pregnancies. In addition, upregulation of MIR451A and downregulation of MIR543 in placentas from FGR group with female newborns and upregulation of MIR520G in placentas from FGR group with male newborns were also noted. MIR451A and MIR543 have been implicated in angiogenesis. Consistent with gene changes, CD34, the microvessel angiogenesis marker, also showed reduced staining only in female FGR group. These findings provide evidence that epigentically regulated gene expression changes in angiogenesis and capillary development influence placental impairment in FGR pregnancies. Our preliminary observations also support for these changes to be driven in a sex-specific manner.

Association of the Severity of Hypertensive Disorders in Pregnancy with Birthweight, Childhood Obesity, and Blood Pressure at Age 7

We aimed to examine the effects of various severities of hypertensive disorders in pregnancy on birthweight, blood pressure (BP), and body mass index in offspring at age 7. In the China Labor and Delivery Survey and the United States Collaborative Perinatal Project (CPP), the relationship of the severity of hypertensive disorders and nutritional and cardiovascular outcomes in offspring was assessed using a multivariable logistic and general linear regression model. In both datasets, those with gestational hypertension were more likely to deliver large for gestational age (LGA) and macrosomia (adjusted odds ratios (aOR) ranged from 1.29 to 1.91), as well as low birth weight (LBW) neonates (aOR ranged from 1.23 to 3.56), compared with normotensive mothers. In the CPP, when gestational hypertension was further stratified into mild and severe, only those with mild gestational hypertension (the mild group) were more likely to deliver macrosomia and LGA (aOR ranged from 1.25 to 1.32). Others (severe gestational hypertension and preeclampsia/eclampsia) were closely related to LBW and small for gestational age (aOR ranged from 1.27 to 2.77). Moreover, children of mothers in the mild group tended to be overweight/obese and had elevated diastolic BP. We concluded that the severity of hypertensive disorders had different effects on birthweight, childhood overweight, and BP.

Dose-response relationships between maternal urinary cotinine and placental weight and ratio of placental weight to birth weight: The Japan Environment and Children's Study

INTRODUCTION

Studies on the relationship between maternal self-reported smoking status and placental weight report inconsistent results. This study examined the relationships between maternal urinary cotinine concentration and placental weight and the ratio of placental weight to birth weight (PW/BW ratio). The study also examined the relationship between maternal smoking status, as determined by cotinine concentration, with placental weight and with PW/BW ratio, stratified by sex of offspring.

METHODS

Our analysis used information of 91,049 mother-child pairs enrolled in the Japan Environment and Children's Study. Maternal urinary cotinine concentration was quantified (during the second or third trimester) with high-performance liquid chromatography-tandem mass spectrometry. Using restricted cubic splines, placental weight and PW/BW ratio were plotted against natural log-transformed cotinine concentration. Taking cotinine levels of <0.17 ng/mL, 0.17 to <21.5 ng/mL (natural log-transformed values, -1.77 to 3.07), and ≥21.5 ng/mL as indicative of non-smokers, passive smokers, and active smokers, respectively, the relationships between maternal smoking status and placental weight and PW/BW ratio were examined, adjusting for confounders.

RESULTS

Placental weight and PW/BW ratio increased with increasing cotinine concentration. After cotinine reached a certain concentration, the placental weight decreased in male offspring whereas it plateaued in female offspring. Compared with not smoking, active smoking during pregnancy significantly increased placental weight and PW/BW ratio.

CONCLUSION

Placental weight responded as an inverted U-shape whereas the PW/BW ratio followed a J-shape with increasing maternal urinary cotinine concentration measured during pregnancy, suggesting exposure to tobacco smoke induces a disproportionate reduction in fetal growth. The effect of tobacco smoke on placental growth varied by sex of offspring.

Normative placental structure in pregnancy using quantitative Magnetic Resonance Imaging

INTRODUCTION

To characterize normative morphometric, textural and microstructural placental development by applying advanced and quantitative magnetic resonance imaging (qMRI) techniques to the in-vivo placenta.

METHODS

We enrolled 195 women with uncomplicated, healthy singleton pregnancies in a prospective observational study. Women underwent MRI between 16- and 40-weeks' gestation. Morphometric and textural metrics of placental growth were calculated from T2-weighted (T2W) images, while measures of microstructural development were calculated from diffusion-weighted images (DWI). Normative tables and reference curves were constructed for each measured index across gestation and according to fetal sex.

RESULTS

Data from 269 MRI studies from 169 pregnant women were included in the analyses. During the study period, placentas undergo significant increases in morphometric measures of volume, thickness, and elongation. Placental texture reveals increasing variability with advancing gestation as measured by grey level non uniformity, run length non uniformity and long run high grey level emphasis. Placental microstructure did not vary with gestational age. Placental elongation was the only metric that differed significantly between male and female fetuses.

DISCUSSION

We report quantitative metrics of placental morphometry, texture and microstructure in a large cohort of healthy controls during the second and third trimesters of pregnancy. These measures can serve as normative references of in-vivo placental development to better understand placental function in high-risk conditions and allow for the early detection of placental mal-development.

Vitamin D alleviates hypoxia/reoxygenation-induced injury of human trophoblast HTR-8 cells by activating autophagy

INTRODUCTION

Attenuation of trophoblast cell dysfunction would be beneficial for retarding pre-eclampsia (PE). Vitamin D has been reported to improve trophoblast cell function in early PE, but the mechanism involved is not fully elucidated. This study is aimed to investigate whether vitamin D alleviates trophoblast cell dysfunction via regulating autophagy.

METHODS

Human trophoblast HTR-8 cells were cultured in hypoxia/reoxygenation (H/R) condition to simulate the oxidative stress state of early PE in vitro. MTT, Transwell and tube formation assays were respectively applied to assess cell proliferation, invasion, and angiogenesis abilities. DCFH-DA staining was performed to detect cellular reactive oxygen species levels. GFP-RFP-LC3 plasmid transfection and transmission electron microscopy were subjected to monitor autophagy. Enzyme-linked immunosorbent assay and Western blot analysis were used to detect autophagy-related and pyroptosis-associated molecules.

RESULTS

H/R led to severe impairments on the bio-function of HTR-8 cells, as evidenced by the deficiency of cell proliferation, invasion, and angiogenesis abilities, and the increase of cellular ROS production. Simultaneously, H/R inhibited autophagy and triggered pyroptosis. 1,25(OH)₂D₃, the hormonally active form of vitamin D, dramatically attenuated H/R-induced trophoblast dysfunction. Also, 1,25(OH)₂D₃ activated autophagy and inhibited pyroptosis. Additionally, autophagy-enhancer rapamycin exerted similar protective effect to that of 1,25(OH)₂D₃, whereas autophagy-inhibitor 3-methyladenine blocked the protective effect of 1,25(OH)₂D₃.

DISCUSSION

The mechanism that vitamin D alleviates trophoblast cell dysfunction is associated with autophagy induction and pyroptosis inhibition.

Comparative risks and predictors of preeclamptic pregnancy in the Eastern, Western and developing world

Preeclampsia (PE) is a complication of pregnancy characterized by hypertension (HTN-Preg), and often proteinuria. If not managed promptly, PE could lead to eclampsia and seizures. PE could also lead to intrauterine growth restriction (IUGR) and prematurity at birth. Although PE is a major cause of maternal and fetal morbidity and mortality, the underlying mechanisms are unclear. Also, there is a wide variability in the incidence of PE, ranging between 2 and 8% of pregnancies in the Eastern, Western and Developing world, suggesting regional differences in the risk factors and predictors of the pregnancy-related disorder. Several demographic, genetic, dietary and environmental factors, as well as maternal circulating biomarkers have been associated with PE. Demographic factors such as maternal race and ethnicity could play a role in PE. Specific genetic polymorphisms have been identified in PE. Maternal age, parity, education and socioeconomic status could be involved in PE. Dietary fat, protein, calcium and vitamins, body weight, and environmental factors including climate changes and air pollutants could also play a role in PE. Several circulating cytoactive factors including anti-angiogenic factors and cytokines have also been associated with PE. Traditional midwifery care is a common practice in local maternity care units, while advanced perinatal care and new diagnostic tools such as uterine artery Doppler velocimetry have been useful in predicting early PE in major medical centers. These PE risk factors, early predictors and diagnostic tools vary vastly in different regions of the Eastern, Western and Developing world. Further understanding of the differences in the demographic, genetic, dietary and environmental factors among pregnant women in different world regions should help in designing a region-specific cluster of risk factors and predictors of PE, and in turn provide better guidance for region-specific tools for early detection and management of PE.

Association between maternal active smoking during pregnancy and placental weight: The Japan environment and Children's study

INTRODUCTION

Maternal smoking during pregnancy is a well-known risk factor for reduced birthweight. However, research investigating the association between maternal smoking and placental weight is scarce and inconsistent. Our study was conducted to evaluate the association between maternal smoking and placental weight and placental weight/birthweight ratio (PW/BW ratio).

METHODS

We used data from a birth cohort study, the Japan Environment and Children's Study (JECS). Main outcome measures were placental weight, PW/BW ratio, and the risk of high PW/BW ratio. High PW/BW ratio was defined as PW/BW ratio above the 90th percentile for gestational age and sex of offspring. The association between maternal smoking and placental weight was estimated as crude and as adjusted beta coefficients by applying linear regression analyses. Logistic regression analyses were also performed to estimate the association between maternal smoking and the risk of high PW/BW ratio.

RESULTS

Of the 91,951 pregnant women, the mean placental weight and the mean PW/BW ratio were lowest for the group of women who had never smoked. Smokers had higher odds ratio for high PW/BW ratio compared with non-smokers. Furthermore, among smokers, the mean placental weight and mean PW/BW ratio were lowest in women who smoked less than 5 daily cigarettes, and highest in women who smoked 20 or more daily cigarettes during pregnancy.

DISCUSSION

Placental weight was greater and PW/BW ratio was higher among smokers compared with non-smokers. Moreover, the number of daily cigarettes was positively associated with heavy placental weight.

[Pathomorphological features of the placentas and the placental sites after in vitro fertilization with a donor egg]

OBJECTIVE

To identify the structural and immunohistochemical features of the placentas and the placental sites after in vitro fertilization (IVF) with a donor egg (surrogate motherhood).

SUBJECT AND METHODS

Morphological and immunohistochemical studies were performed on the placental (a placental disk) and placental bed materials obtained after caesarean delivery. The investigation enrolled 26 patients whose pregnancy occurred with IVF with a donor egg according to the surrogacy (IVF-S) program. A comparison group included 13 patients whose pregnancy occurred after IVF with their own eggs. An immunohistochemical study was conducted on paraffin sections made from biopsy material; mouse antibodies to total cytokeratin (clone AE1/AE3, 'Dako'), HLA-DR (clone TAL.1B5, 'Dako'), and CD138 (clone MI15, 'Dako') were used as primary antibodies.

RESULTS

The histological examination of the placentas in the IVF-S group showed the high incidence of central ischemic heart attacks (69%), dissociated cotyledon development (61%), pathological villous immaturity mainly with the predominance of intermediate differentiated villi (46%), and massive perivillous fibrinoid deposition (73%). The obtained differences between with the study and comparison groups were significant (p<0.05). The IVF-S group was characterized by the development of lymphoplasmacytic deciduitis (1.23±0.4 and 0.5±0.3 scores). Examination of the placental site biopsy material in the IVF-S group revealed the following changes: remodeling of the spiral arteries was incomplete in more than 40% of cases, and in 30% of the spiral arteries had no gestational changes. In the comparison group, more than 90% of the spiral arteries were characterized by complete remodeling during pregnancy. There was also an increase in the count of multinucleated trophoblastic giant cells (104.56±4.21 and 65.67±14.45) and HLA-DR positive cells (41.86±5.32 and 29.00±1.87).

CONCLUSION

The placentas and the placental sites of the women whose pregnancy occurred with IVF-S are characterized by the development of high lyoplasmacytic deciduitis activity and pronounced placental immune alterations manifested by the high incidence of immune responses at the sites of the closest contact between maternal and fetal tissues. The placental bed exhibited defective spiral artery remodeling, development of chronic inflammatory lesions in the perivascular areas, and an increase in the counts of HLA-DR positive cells and multinucleated trophoblastic giant cells.

Structural, immunohistochemical and molecular features of placentas and placental sites after in vitro fertilization with donor eggs (surrogate motherhood)

OBJECTIVE

to identify structural, immunohistochemical and molecular features of placentas and placental sites afterin vitro fertilization (IVF) with donor eggs (surrogate motherhood).

STUDY DESIGN

morphological and immunohistochemical studies were performed on placental material obtained after delivery by caesarean section. The study included 26 women patients whose pregnancy resulted from IVF with a donor egg (IVF-SM group). The comparison group included 13 women patients whose pregnancy occurred after IVF with their own eggs (IVF-OE). Immunohistochemistry of biopsy material was performed using mouse antibodies to total cytokeratin (clone AE1/AE3) and murine antibodies to HLA-DR (clone TAL.1B5). Molecular studies were performed on DNA samples isolated from venous blood. HLA-DNA-TEH reagent kits and polymerase chain reaction were used for genotyping the main human histocompatibility complex class II (DQA1, DQB1 and DRB1).

RESULTS

Histological examination of placenta in IVF-SM group showed a high incidence of central ischemic infarctions (69% of cases), dissociated cotyledon development (61%), pathological villus immaturity (46%) and massive perivillous fibrin deposition (73%). This group also had a pronounced lymphoplasmacytic deciduitis, which was 2 times higher than in the control group, and an expressed inflammatory process in the placental sites. Remodeling of the spiral arteries was incomplete in more than 40% of cases, and 30% of spiral arteries had no gestational changes. In comparison group, a complete gestational adjustment was found in more than 90% of spiral arteries. A focal lymphohistiocytic infiltration in perivascular regions, and a decrease in the number of multinucleated cells as compared with the control were also observed. For seven female surrogate mothers and their children, allelic polymorphisms of genes of HLA II class were studied.

CONCLUSION

Placental material of women from IVF-SM group is characterized by complex immune response in sites of tight contact between maternal and fetal tissues. The immune pathogenesis is associated with an increase in the number of HLA-DR positive cells, defects in remodeling of the spiral arteries, development of areas of chronic inflammation in perivascular regions, and a decrease in the number of multinucleated cells. Genetic incompatibility between alleles of HLA II genes can be a molecular predictor of impaired immune tolerance.