Influencia de la anastomosis de las arterias umbilicales (Hyrtl's) en la morfometría y eficiencia placentaria / Influence of the anastomosis of the umbilical arteries (Hyrtl's) on the morphometry and efficiency of the placenta

La anastomosis de Hyrtl's (AH), vaso único con amplia variabilidad anatómica, comunica las arterias umbilicales cerca de la inserción del cordón umbilical en las placentas humanas. El objetivo del presente trabajo fue determinar si existe relación entre las características morfométricas de la placenta y la presencia de anastomosis y analizar si esta tiene influencia en la eficiencia placentaria. Estudio descriptivo. Se analizaron 60 placentas provenientes de madres que aceptaron participar en la investigación, embarazo único, a término (entre 37,0 y 41,6 semanas), con edades entre 18 y 37 años, con al menos cuatro visitas a control prenatal, sin comorbilidades. Las características placentarias de peso, diámetros y grosor se tomaron en fresco. Una vez fijadas con formaldehido al 10 %, mediante disección se ubicó, clasificó y fotografió la anastomosis. El peso de la placenta fue 494,4 ± 87,1 gramos, el grosor central correspondió a 1,7 ± 0,4 cm, DM 19,9 ± 2,0 cm y Dm 18,4 ± 1,7 cm. La inserción de cordón predominante fue excéntrica (65 %) y la forma discoidea u ovalada (60 %). En 51 placentas se ubicó la presencia de anastomosis (85 %). En el grupo de placentas con presencia AH se encontró un peso placentario más bajo al compararlo con el grupo que no presentó AH, el resto de las características morfométricas de la placenta, incluido el tipo de inserción de cordón umbilical no presentaron relación con la anastomosis. La eficiencia placentaria expresada con la relación entre peso neonato/peso placenta presentó diferencias significativas en el grupo con presencia de anastomosis, con mayores valores comparados con el grupo sin anastomosis. La presencia de AH contribuye positivamente a la eficiencia placentaria. Sin embargo, el incremento del peso placentario puede ser un efecto compensador de la placenta y no siempre indica una mayor eficiencia funcional del órgano.

SUMMARY: Hyrtl's anastomosis (HA), a single vessel, with wide anatomical variability, communicates the umbilical arteries, near the insertion of the umbilical cord in human placentas. The objective of this study was to determine if there is a relationship between the morphometric characteristics of the placenta and the presence of the anastomosis and to analyze if this influences the placental efficiency. Descriptive study. We analyzed 60 placentas from mothers who agreed to participate in the study, single pregnancy, term (between 37.0 and 41.6 weeks), aged between 18 and 37 years with at least four visits to prenatal control, without comorbidities. The placental characteristics of weight, diameters and thickness were taken fresh. Once fixed with 10 % formaldehyde, the anastomosis was located, classified, and photographed by dissection. The weight of the placenta was 494.4 ± 87.1 g, the central thickness corresponded to 1.7 ± 0.4 cm, the MD 19.9 ± 2.0 cm and Dm 18.4 ± 1.7 cm: The predominant cord insertion was eccentric, with 65 % and the discoid or oval shape with 60 %. In 51 placentas the presence of anastomosis was found (85 %). In the group of placentas with AH presence, a lower placental weight was found when compared to the group that did not present AH, the rest of the morphometric characteristics of the placenta, including the type of umbilical cord insertion, were not related to the anastomosis. Placental efficiency expressed as the neonatal weight/placental weight ratio showed significant differences in the group with presence of anastomosis, with higher values compared to the group without anastomosis. The presence of HA contributes positively to placental efficiency. However, the increase in placental weight may be a compensatory effect of the placenta and does not always indicate a greater functional efficiency of the organ.

A Study On Placental Weight And Its Assocition With Maternal And Neonatal Characteristics

Placenta plays a vital role in normal fetal development and failure of placenta to gain weight and insufficiency of its function can result in fetal disorders. We performed this study to determine placental weight with birth weight, maternal diabetes, pre–eclampsia/eclampsia, Anemia, Apgar score, SNCU admission, in a longitudinal cross–sectional study, women with single pregnancy, and gestational age between 29–42 weeks were studied. The placental weight, birth weight, maternal age, gestational age, hypertensive disorders in pregnancy, maternal diabetes, Apgar score in 5th minutes after delivery were examined. Two fifty pregnant women were included in the study. The mean and standard deviation for maternal ages and gestational ages at deliveries were 25.6 ± 4.4 and 38.3 ± 4.4 days, respectively. The mean and standard deviation of neonates’ weights at birth and placental weights were 2709 ± 614.0g and 466.6 ± 112.2 g, respectively. The prevalences of low and high placental weights were 2% and 2.8%, respectively. There were statistically significant relationships between placental weight, placental weight ratio(PWR) and birth weight, maternal diabetes, hypertensive disorders in pregnancy, anemia, Apgar score, SNCU admission . Our findings indicate that placental weight Ratio(PWR) can be associated with important variables influencing some maternal and neonatal outcomes .Careful attention to placenta growth during pregnancy, for example by ultrasonography, can guide physicians to assess neonatal health.

Placental weight and birth weight to placental weight ratio in monochorionic and dichorionic growth-restricted and non-growth-restricted twins

OBJECTIVE: The aim of the present study was to compare the placental weight and birth weight/placental weight ratio for intrauterine growth-restricted and non-intrauterine growth-restricted monochorionic and dichorionic twins. METHODS: This was a retrospective analysis of placentas from twin pregnancies. Placental weight and the birth weight/placental weight ratio were compared in intrauterine growth-restricted and non-intrauterine growth-restricted monochorionic and dichorionic twins. The association between cord insertion type and placental lesions in intrauterine growth-restricted and non-intrauterine growth-restricted monochorionic and dichorionic twins was also investigated. RESULTS: A total of 105 monochorionic (intrauterine growth restriction=40; non-intrauterine growth restriction=65) and 219 dichorionic (intrauterine growth restriction=57; non-intrauterine growth restriction=162) placentas were analyzed. A significantly lower placental weight was observed in intrauterine growth-restricted monochorionic (p=0.022) and dichorionic (p<0.001) twins compared to non-intrauterine growth-restricted twins. There was no difference in the birth weight/placental weight ratio between the intrauterine growth restriction and non-intrauterine growth restriction groups for either monochorionic (p=0.36) or dichorionic (p=0.68) twins. Placental weight and the birth weight/placental weight ratio were not associated with cord insertion type or with placental lesions. CONCLUSION: Low placental weight, and consequently reduced functional mass, appears to be involved in fetal growth restriction in monochorionic and dichorionic twins. The mechanism by which low placental weight influences the birth weight/placental weight ratio in intrauterine growth-restricted monochorionic and dichorionic twins needs to be determined in larger prospective studies.

A Study of Placental Weight and Fetal Outcome In Different Grades of Pregnancy Induced Hypertension.

Introduction and Objectives: Placenta is a feto-maternal organ which is vital for maintaining pregnancy and promoting normal development of the fetus. The weight of the placenta is functionally significant because it is related to villous surface area and to fetal metabolism. Present study has done to record the placental weight and co-relate with the corresponding fetal weight. Materials and Methods: A total of 100 placentae were studied, out of which 50 placentae belong to pregnancy induced hypertension and 50 placentae were of normotensive pregnant mothers. The weight of placenta and weight of fetus were compared between normotensive (Control) and hypertensive mothers (Cases). Results: The mean weight of placenta in study group was low as compared to that in the control group. The birth weight of newborn was low with increasing grades of hypertension compared to control groups. The fetoplacental weight ratio was higher in case of mild and severe preeclampsia. The incidence of stillbirth was 0.5%, 12.5% and 20% in mild pre-ecampsia, severe preeclampsia and eclampsia respectively. Conclusion: In present study, the birth weight was low with increasing grades of hypertension compared to control groups. The fetal: placental weight ratio was higher in case of mild and severe preeclampsia. The incidence of eclampsia was more common in primigravida where as mild preeclampsia was more common in multigravida. The mean weight of placenta in study group was low compared to control group. Thus study of placental changes in pregnancy induced hypertension may help us to understand patho-physiological mechanisms and design treatment plans for better maternal and foetal outcome. Modern sophisticated techniques like ultrasonography have made it possible to study the necessary placental parameters in utero. This helps in assessing the foetal outcome and management.

The significance of placental ratios in pregnancies complicated by small for gestational age, preeclampsia, and gestational diabetes mellitus

OBJECTIVE: This study aimed to evaluate the placental weight, volume, and density, and investigate the significance of placental ratios in pregnancies complicated by small for gestational age (SGA), preeclampsia (PE), and gestational diabetes mellitus (GDM). METHODS: Two hundred and fifty-four pregnant women were enrolled from August 2005 through July 2013. Participants were divided into four groups: control (n=82), SGA (n=37), PE (n=102), and GDM (n=33). The PE group was classified as PE without intrauterine growth restriction (n=65) and PE with intrauterine growth restriction (n=37). Birth weight, placental weight, placental volume, placental density, and placental ratios including birth weight/placental weight ratio (BPW) and birth weight/placental volume ratio (BPV) were compared between groups. RESULTS: Birth weight, placental weight, and placental volume were lower in the SGA group than in the control group. However, the BPW and BPV did not differ between the two groups. Birth weight, placental weight, placental volume, BPW, and BPV were all significantly lower in the PE group than in the control group. Compared with the control group, birth weight, BPW, and BPV were higher in the GDM group, whereas placental weight and volume did not differ in the two groups. Placental density was not significantly different among the four groups. CONCLUSION: Placental ratios based on placental weight, placental volume, placental density, and birth weight are helpful in understanding the pathophysiology of complicated pregnancies. Moreover, they can be used as predictors of pregnancy complications.

Placental morphometry in relation to birth weight of full term newborn babies.

Background: In obstetrics the relationship of birth weight and the perinatal outcome has long been appreciated, however an often neglected parameter is the placental changes. Placenta is a vital organ for maintaining pregnancy and promoting normal foetal development. Foetal outcome is adversely influenced by pathological changes observed in placenta. Objectives: To assess the morphology of placenta in normal and low birth weight babies. To correlate the morphometric analysis with birth weight between the two groups. Study design: Cross-sectional descriptive study. Study setting: Department of Anatomy, Chalmeda Anandrao Institute of Medical Sciences, Karimnagar, Andhra Pradesh from January to June 2011. Methods: Total 374 human placentae from uncomplicated pregnancies were studied for the morphology and compared between low birth weight babies and normal weight babies. Results: The morphometric parameters of placenta like, weight, volume were significantly lower in low birth weight group compared to normal group. Placental weight and placental volume had significant correlation with the birth weight of new born. Conclusion: The placental weight increased according to the birth weight. Placental parameters and its ratio to birth weight were significantly associated with some adverse pregnancy outcomes.

The change of lipid peroxidation and superoxide dismutase activity in placenta by the birth to placental weight ratio at birth / 대한산부인과학회지

OBJECTIVE: The object of this study is to determine whether there is any association between birth to placenta weight ratio and oxidative stress. 34 pregnant women (who gave birth after 36 weeks of pregnancy by cesarean section without labor) were divided into three groups according to their birth to placenta weight ratio. The degree of lipid peroxidation in the placenta and the activity of superoxide dismutase which removes peroxide products were compared in three groups METHODS: In the 34 women who gave birth through cesarean section before labor, we classified the patients to three groups ; the first group (n=13) women whose birth to placenta weight ratio was equal to or above 5.0. The second group (n=14) whose ratio was between 4.3 and 5.0. The third group (n=7) whose ratio was less than 4.3. We measured malondialdehyde (MDA) as a indicative marker of lipid peroxidation through a Thibarbituric Acid (TBA) method, and the activity of superoxide dismutase (SOD) as a antioxidant defense system through a Bioxytech SOD-525 kit (OxisResearch, USA). Data were analyzed statistically using ANOVA test (SPSS for Windows 10.0) and students's t-test. RESULTS: In a group consisting of preeclampsia and FGR, the birth to placenta weight ratio had no significant difference. The mean MDA concentration of group 1 was 7.38+/-6.6 nmole/mg protein, which was significantly lower than both mean of group 2 (17.39+/-12.54 nmole/ mg protein) and group 3 (19.89+/-8.69 nmole/mg protein), There were no significant differences between group 2 and 3. The MDA/SOD ratio of group 1 was 1.01+/-0.97, which was significantly lower than those of group 2 and 3, which were 2.79+/-2.92 and 3.29+/-2.18, respectively. However, there were no significant differences between group 2 and 3. CONCLUSIONS: It is possible to assume that oxidative stress participates in the mechanism of decreased birth to placental weight ratio. Th decreased ratio is probably due to excessive lipid peroxides in placenta. To evaluate the association of birth to placental weight ratio with oxidative stress.