Morphometric characteristics of the umbilical cord and vessels in fetal growth restriction and pre-eclampsia

Ultrasound evaluation of the size of the umbilical cord vessels and Wharton's jelly and correlation with intrapartum CTG findings

OBJECTIVE

To compare the sonographic measurement of the umbilical cord between women with or without repetitive decelerations during the first stage of labor.

STUDY DESIGN

Prospective study including a non-consecutive cohort of women at term gestation carrying a normal sized fetus at term in cephalic presentation. The cross-sectional area of the umbilical cord, of its vessels and the amount of the Wharton's jelly were assessed at 2D ultrasound upon labor admission. The CTG traces recorded in labor were retrospectively evaluated and the biometric parameters of the umbilical cord were compared between women with or without repetitive decelerations during the first stage and their correlation with the total deceleration area/total length (stage I TDA/t) of the first stage of labor (overall and following the rupture of membrane) was assessed.

RESULTS

Overall, 113 women were included, of whom 21 (18.6 %) presented repetitive decelerations during the first stage of labor. In this latter group, the umbilical cord showed a significantly smaller total arterial area (24.4 ± 10.7 vs. 19.6 ± 9.0 mm2; p = 0.02), vein area (46.8 ± 13.6 vs. 34.1 ± 13.3 mm2; p < 0.001) as well Wharton's Jelly (WJ) area (122.7 ± 32.1 vs. 79.3 ± 11.1 mm2; p < 0.001) compared with fetuses with a normal CTG. At logistic regression analysis the WJ area was associated with the occurrence of repetitive decelerations during the first stage of labor (p < 0.001). The I stage TDA/t overall and after the rupture of membranes was found to be negatively correlated with the WJA (Spearman's coefficient -0.40; p < 0.001 and -0.45; p < 0.001 respectively).

CONCLUSION

In normal sized infants a reduced umbilical cord thickness is associated with an increased occurrence of repetitive decelerations during the first stage of labor. The severity of these decelerations is negatively correlated to the amount of WJ.

Placental Macrovascular Pattern from Pregnancies with Maternal Hypertensive and Fetal Growth Capacity Complications

Histomorphometric measurements of the wall thickness and internal diameter of the macrovessels of the chorionic villi of placentas from pregnancies complicated by preeclampsia or fetal growth restriction in comparison with normotensive pregnancy.

METHODS

The research included placentas from singleton pregnancies complicated by preeclampsia and/or fetal growth restriction, women delivered in medical institutions in Karaganda city (Kazakhstan). Placentas were divided into three groups: PE (n = 59), isolated FGR (n = 24), and PE with FGR (n = 41). The control group consisted of normotensive pregnancies, compared by gestation period. Placental examination and selection of placental tissue fragments were carried out in accordance with the consensus recommendations of the Amsterdam Placental Workshop Group. The sections were stained with hematoxylin and eosin and Masson trichrome. Morphometric measurements were performed using ImageJ software version 1.52p.

RESULTS

Our data showed that, in the PE group, there was a significant decrease in the wall thickness of the proximal and distal vessels with an increase in internal diameter compared with the control group (p < 0.01). In the PE + FGR group, there was a thickening of the wall of the proximal part of the vessels with a decrease in their lumen and a decrease in the wall thickness of the vessels with an increase in the lumen in the distal part compared with the control group (p < 0.01).

CONCLUSIONS

Two histopatterns of placental macrovessels in preeclampsia were revealed: the histophenotype of diffuse (proximal and distal) ectatic macroangiopathy with a thin vascular wall with a decrease in the thickness of the muscle layer and the histophenotype of proximal fibromuscular sclerosis with vascular obliteration/spasm and distal ectatic macroangiopathy. We believe that significant structural differences in vascular remodeling may reflect the different temporal and spatial nature of the pathological factor. Future research is needed to investigate the associations between histopatterns of placental vascular remodeling in preeclampsia and long-term perinatal/maternal outcomes.

Investigation of Urotensin II expression in placenta and umbilical cord in pregnancies with intrauterine growth restriction by histological and biochemical methods

OBJECTIVE

In this study, it was aimed to investigate Urotensin II in intrauterine growth restriction (IUGR) and its connection to autophagy and/or apoptosis in placenta and umbilical cord by immunohistochemical and biochemical methods.

MATERIALS AND METHODS

The study included 30 healthy pregnant women and 30 pregnant women with IUGR, aged 19-45, at Atatürk University Gynecology Clinic. Samples were collected from placenta, umbilical cord, maternal blood, and umbilical cord blood during delivery. Histopathological examination was carried out on placenta and umbilical cord, and UTII, Beclin 1, and caspase 3 expressions were analyzed in these tissues. Biochemical analysis was performed on maternal and umbilical cord serum samples.

RESULTS

In healthy placentas, normal villus formation was seen, but those with IUGR showed accelerated villus maturation, causing inadequate nutrition and development. IUGR placentas had fibrin deposition, villous edema, syncytial nodes increase, and intervillous distance. Umbilical cords of IUGR group had differences in vessel wall thickness, arterial lumens, and vessel number. Higher levels of UTII, Beclin 1, and caspase 3 were found in IUGR placenta and cord. Beclin 1 and caspase 3 levels were significantly higher in IUGR group compared to controls, while UTII levels were not significantly different in maternal and cord serums.

CONCLUSION

As a result of our findings, UTII increase in placenta and umbilical cord may lead to IUGR formation by inducing autophagy and apoptosis.

Gross and histological examination of Wharton's Jelly in the equine umbilical cord

Wharton's jelly (WJ) is fundamental for the well-being of the fetus, binding to the umbilical vessels and protecting them from twisting and compression. Gross and microscopic studies have been undertaken on the umbilical cord (UC) of human placentae in both normal and high-risk pregnancies, however there is limited research on equine UC. The aim of this study was to describe microscopically and immunohistochemically the equine UC in normal pregnancies, with particular attention to WJ. Forty-seven healthy mares, with no complications during pregnancy, admitted to the hospital for attending delivery were enrolled. Clinical data was collected at foaling on foal health and placental characteristics. UC samples were collected from three sites (amniotic, allantoic and in the region of vein anastomosis) for histology. The thickness of different layers of arteries and veins and WJ in different UC portions were measured (μm). Wharton's Jelly was weighted (g) and its sections were stained with Masson's trichrome, orcein technique and silver impregnation. Immunohistochemistry was undertaken using antibodies raised-against collagen type I, V, VI and fibrillin. Forty-seven UCs, from 19 colt and 28 filly foals, were analyzed for WJ weight and 8/47 UCs were examined histologically. Warton's jelly was only found in the amniotic portion of the UC closest to the foal's abdomen. The weight of WJ (4.0 ± 3.3 g) did not vary between colts and fillies and it was not correlated with any of the clinical or UC parameters measured. The tunica media of arteries and veins was thicker in the amniotic portion of the UC, as described in human UCs in late pregnancy. This finding could be an adaptation to aid in resisting compression because of fetal movements and UC twisting. The umbilical vein was thicker than the umbilical arteries in the tunica media and tunica adventitia in the sections examined throughout the length of the cord. This preliminary study describes gross and histological WJ's structure in the equine species. However, further studies are required to better characterize UC's changes throughout pregnancy and in the presence of mare's or fetal disease.

Proteomic analysis of the umbilical cord in fetal growth restriction and preeclampsia

Fetal growth restriction (FGR) is associated with adverse perinatal outcomes. Pre-eclampsia (PreE) increases the associated perinatal morbidity and mortality. The structure of the umbilical cord in the setting of FGR and PreE is understudied. This study aimed to examine changes in the umbilical cord (UC) composition in pregnancies complicated by FGR and FGR with PreE. UC from gestational age-matched pregnancies with isolated FGR (n = 5), FGR+PreE (n = 5) and controls (n = 5) were collected, and a portion of the UC was processed for histologic and proteomic analysis. Manual segmentation analysis was performed to measure cross-section analysis of umbilical cord regions. Wharton’s Jelly samples were analyzed on a tims-TOF Pro. Spectral count and ion abundance data were analyzed, creating an intersection dataset from multiple mass spectrometry search and inference engines. UCs from FGR and FGR with PreE had lower cross-sectional area and Wharton’s Jelly area compared with control (p = 0.03). When comparing FGR to control, 28 proteins were significantly different in abundance analysis and 34 in spectral count analysis (p < 0.05). Differential expression analysis between PreE with FGR vs controls demonstrated that 48 proteins were significantly different in abundance and 5 in spectral count. The majority of changes occurred in proteins associated with extracellular matrix, cellular process, inflammatory, and angiogenesis pathways. The structure and composition of the UC is altered in pregnancies with FGR and FGR with PreE. Future work in validating these proteomic differences will enable identification of therapeutic targets for FGR and FGR with PreE.

Development of a Bioartificial Vascular Pancreas

Transplantation of pancreatic islets has been shown to be effective, in some patients, for the long-term treatment of type 1 diabetes. However, transplantation of islets into either the portal vein or the subcutaneous space can be limited by insufficient oxygen transfer, leading to islet loss. Furthermore, oxygen diffusion limitations can be magnified when islet numbers are increased dramatically, as in translating from rodent studies to human-scale treatments. To address these limitations, an islet transplantation approach using an acellular vascular graft as a vascular scaffold has been developed, termed the BioVascular Pancreas (BVP). To create the BVP, islets are seeded as an outer coating on the surface of an acellular vascular graft, using fibrin as a hydrogel carrier. The BVP can then be anastomosed as an arterial (or arteriovenous) graft, which allows fully oxygenated arterial blood with a pO2 of roughly 100 mmHg to flow through the graft lumen and thereby supply oxygen to the islets. In silico simulations and in vitro bioreactor experiments show that the BVP design provides adequate survivability for islets and helps avoid islet hypoxia. When implanted as end-to-end abdominal aorta grafts in nude rats, BVPs were able to restore near-normoglycemia durably for 90 days and developed robust microvascular infiltration from the host. Furthermore, pilot implantations in pigs were performed, which demonstrated the scalability of the technology. Given the potential benefits provided by the BVP, this tissue design may eventually serve as a solution for transplantation of pancreatic islets to treat or cure type 1 diabetes.

Umbilical Cord miRNAs in Small-for-Gestational-Age Children and Association With Catch-Up Growth: A Pilot Study

CONTEXT

Catch-up growth in infants who are small for gestational age (SGA) is a risk factor for the development of cardiometabolic diseases in adulthood. The basis and mechanisms underpinning catch-up growth in newborns who are SGA are unknown.

OBJECTIVE

To identify umbilical cord miRNAs associated with catch-up growth in infants who are SGA and study their relationship with offspring's cardiometabolic parameters.

DESIGN

miRNA PCR panels were used to study the miRNA profile in umbilical cord tissue of five infants who were SGA with catch-up (SGA-CU), five without catch-up (SGA-nonCU), and five control infants [appropriate for gestational age (AGA)]. The miRNAs with the smallest nominal P values were validated in 64 infants (22 AGA, 18 SGA-nonCU, and 24 SGA-CU) and correlated with anthropometric parameters at 1 (n = 64) and 6 years of age (n = 30).

RESULTS

miR-501-3p, miR-576-5p, miR-770-5p, and miR-876-3p had nominally significant associations with increased weight, height, weight catch-up, and height catch-up at 1 year, and miR-374b-3p, miR-548c-5p, and miR-576-5p had nominally significant associations with increased weight, height, waist, hip, and renal fat at 6 years. Multivariate analysis suggested miR-576-5p as a predictor of weight catch-up and height catch-up at 1 year, as well as weight, waist, and renal fat at 6 years. In silico studies suggested that miR-576-5p participates in the regulation of inflammatory, growth, and proliferation signaling pathways.

CONCLUSIONS

Umbilical cord miRNAs could be novel biomarkers for the early identification of catch-up growth in infants who are SGA. miR-576-5p may contribute to the regulation of postnatal growth and influence the risk for cardiometabolic diseases associated with a mismatch between prenatal and postnatal weight gain.

Maternal Hematological Parameters and Placental and Umbilical Cord Histopathology in Intrauterine Growth Restriction

OBJECTIVE

To investigate the placental and umbilical cord histopathology in intrauterine growth restriction (IUGR) and their relation to second-trimester maternal hematological parameters.

MATERIALS AND METHODS

Patients were selected for the IUGR group based on estimated fetal weight below the 10th percentile. Patients were recruited into the control group randomly. Patients were followed up with ultrasound, and blood samples were taken between the 20th and 24th gestational weeks. After delivery and formalin fixation, weight and volume of the placenta were recorded and histologic samples were processed.

RESULTS

Maternal platelet count strongly correlates with placental weight (r = 0.766). On the other hand, neonatal weight correlates with placental volume (r = 0.572) rather than with placental weight (r = 0.469). Umbilical arterial lumen cross-sectional area correlates with birth weight (r = 0.338).

CONCLUSIONS

Maternal hematological parameters do not seem to affect neonatal outcome. Our main findings are the correlation of maternal platelet count with placental weight, the correlation of placental volume with birth weight being stronger than the correlation of placental weight with birth weight, and the correlation of umbilical artery lumen cross-sectional area with neonatal weight. Mild histopathologic alterations might occur in normal pregnancies; however, sufficient fetal nutrition can be maintained. This compensatory function of the placenta seems to be insufficient when two or more pathologies are present, which is characteristic for IUGR.

Fetal Growth Restriction Induces Heterogeneous Effects on Vascular Biomechanical and Functional Properties in Guinea Pigs (Cavia porcellus)

Aim: Fetal growth restriction (FGR) is associated with a variety of cardiometabolic diseases in adulthood which could involve remodeling processes of the vascular walls that could start in the fetal period. However, there is no consensus whether this remodeling affects in a similar way the whole vascular system. We aimed to determine the effects of FGR on the vasoactive and biomechanical properties of umbilical and systemic vessels in fetal guinea pigs.

Methods: FGR was induced by implanting ameroid occluders at mid-gestation in uterine arteries of pregnant guinea pigs, whilst the control group was exposed to simulated surgery. At the term of gestation, systemic arteries (aorta, carotid and femoral) and umbilical vessels were isolated to determine ex vivo contractile and biomechanical responses (stretch-stress until rupture) on a wire myograph, as well as opening angle and residual stresses. Histological characteristics in tissue samples were measured by van Gieson staining.

Results: Aorta and femoral arteries from FGR showed an increased in biomechanical markers of stiffness (p < 0.01), contractile capacity (p < 0.05) and relative media thickness (p < 0.01), but a reduced internal diameter (p < 0.001), compared with controls. There were no differences in the biomechanical properties of carotid and umbilical from control and FGR fetuses, but FGR umbilical arteries had a decreased contractile response to KCl (p < 0.05) along with a reduced relative media thickness (p < 0.05).

Conclusion: Altogether, these changes in functional, mechanical and morphological properties suggest that FGR is associated with a heterogeneous pro-constrictive vascular remodeling affecting mainly the lower body fetal arteries. These effects would be set during a pathologic pregnancy in order to sustain the fetal blood redistribution in the FGR and may persist up to adulthood increasing the risk of a cardiovascular disease.