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The role of a healthy placenta as the interface between mother and fetus, which regulates the intrauterine environment and affects fetal and pregnancy outcomes, points to placental examination as a potentially useful diagnostic tool. Placental macroscopic and microscopic patterns are routinely evaluated when pregnancy complications occur. Moreover, placental measures particularly the ratio between fetal and placental weight have been reported to correlate with maternal characteristics, such as BMI as well as with birth-weight and fetal gender. Our pilot study evaluates the feasibility of the placental measures' reproducibility intra-operators. We enrolled 50 consecutive singleton pregnancies including physiological pregnancies and any pre-existing maternal disease or maternal and fetal complication. We conducted a macroscopic analysis of fetal adnexa with four different operators assessing pathological findings or other abnormalities. Intra-class correlation coefficient (ICC) and Cohen and Fleiss kappa coefficient were used to assess the degree of consistency between operators. The results of our study show that the placental morphometric analysis is a reproducible method.

Introduction: Proper placental gross examination requires weighing the placental disc trimmed of fetal membranes and the umbilical cord. However, untrimmed placental weights are often reported, both in cases submitted for consultation and in publications. Thus, determining the contribution of membranes and cords to untrimmed placental weights would be helpful in estimating the true trimmed weight of placentas. We sought to report the average weights of membranes and cord in term placentas and to correlate these weights with common placental pathologies., Methods: A total of 500 consecutive placentas delivered between 36 and 42 weeks gestational age were subjected to a modified grossing protocol, in which the weight of the trimmed and untrimmed placentas, fetal membranes, and umbilical cords were recorded. Acute chorioamnionitis, meconium, maternal vascular malperfusion, and fetal vascular malperfusion were included as pathologic correlates. Clinical data such as the presence of fetal hydrops, intrauterine growth restriction, intrauterine fetal demise, and maternal diabetes were also recorded., Results: The mean weights of the trimmed placenta, fetal membranes, and umbilical cords were 442 g (180-805 g), 47.2 g (16-108 g), and 37.9 g (9-126 g), respectively. The fetal membranes and umbilical cord weights contributed a mean of 16% to the total untrimmed placental weight. Meconium was associated with heavier fetal membranes. Fetal vascular malperfusion was associated with longer umbilical cord and thus also with heavier umbilical cords. Maternal vascular malperfusion and intrauterine growth restriction were associated with lighter placentas., Discussion: The trimmed placental disc weight may be estimated by subtracting 16% (ie, weight of the fetal membranes and umbilical cord) from the untrimmed placental weight, or alternatively by subtracting the mean weight of the membranes and umbilical cord. It is important to consider the effects of meconium, fetal and maternal vascular malperfusion, and intrauterine growth restriction on membrane and cord weights when estimating the trimmed placental disc weight.

Detailed knowledge of the anatomy of human placenta vessels is clinically essential and requires the use of many different anatomical and histological techniques. One of the interesting methods of visualising vessels is the corrosion technique. It enables spatial visualisation of the vascular network of the analysed organ. The authors present a developed, own method of preparing the corrosive preparations from human placenta. They underline the advantages and disadvantages of this technique. They describe solutions aimed at reducing the costs of the process. They show that corrosion technology enables relatively fast and inexpensive visualisation of arterial and venous vessels of the human placenta., (Copyright © 2019 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Macroscopic evaluation of the placenta is an essential post-partum examination in the alpaca and can be of special interest in case of abortion, premature birth or stillbirth. Since there are not many reference values regarding macroscopic properties of normal alpaca placentas, a small descriptive study was conducted. Only placentae from normally foaling alpaca mares, giving birth to healthy crias, after a full-term and uneventful gestation (±350 days; range 335-360 days) were taken into account (N = 11). Crias weighed (±SD) 7.7 ± 2.25 kg (range 5.5-10 kg), while the mean weight of the full-term placentas was 0.8 ± 0.19 kg, that is 10% of the bodyweight of the crias. The weight of the allantoamnion and chorion was 0.2 ± 0.07 kg and 0.5 ± 0.13 kg, respectively. The umbilical cord length was 8.8 ± 2.84 cm, and the length of the pregnant and non-pregnant uterine horns was 69.4 ± 12.77 cm and 54.5 ± 6.81 cm, respectively. The length of the corpus was 14.6 ± 4.68 cm, and the distance from the umbilicus to the corpus was 18.5 ± 6.13 cm. The tissue volume of the allantoamnion was 0.14 ± 0.079 L, and the chorionic volume was 0.37 ± 0.078 L. The surface area of the allantoamnion and the chorion was 87.6 ± 15.56 dm 2 and 72.3 ± 9.28 dm 2 , respectively. All placentas had small calcifications either around the umbilical cord alone or around the umbilicus and blood vessels of the pregnant uterine horn. These measurements could be used to macroscopically evaluate alpaca placentas, although more research is needed to extend our knowledge of macroscopic evaluation of normal and abnormal placentas., (© 2019 Blackwell Verlag GmbH.)

Objective: To determine if pre-specified placental abnormalities among newborns with hypoxic-ischemic encephalopathy (HIE) differ compared to newborns admitted to a NICU without encephalopathy., Study Design: Retrospective case-control study of newborns with HIE (2006-2014) and controls matched for birth year, gestational age, weight, and gender. One pathologist reviewed archived placental sections using pre-specified criteria., Results: Sixty-seven newborns had HIE, 46 had available placentas and were matched with 92 controls. HIE had more maternal vascular malperfusion (46% vs 25%, p = 0.02), fetal vascular malperfusion (13% vs 0%, p < 0.001), and clinical abruption (22% vs 4%, p = 0.001). Controls had more normal placentas (29% vs 7%, p = 0.002), and chorioamnionitis (30% vs 9%, p = 0.005). Pre-specified placental lesions occurred in 87% of HIE and 65% of controls (p = 0.008) and identified >90% of primary diagnoses., Conclusions: Pre-specified placental lesions identified nearly all abnormalities in HIE and represented both acute and chronic processes.

The umbilical cord and placental have been considered to significantly contribute to the perinatal outcome. Long or short cord can lead to intrauterine fetal demise. So this type of study in placenta and umbilical cord can yield information for immediate and later management of newborn. This information may also be essential for protecting the attending physician in the event of a fetal outcome. This Cross sectional descriptive study would provide information about the length of umbilical cord in different gestational age groups in Bangladesh. To fulfill this aim the study was performed on 60 human placentas and umbilical cords and Gestational age (in weeks) categorized as Group A (28-32), Group B (33-37), and Group C 38 weeks and above. These samples were collected from normal pregnancy in Gynecology and Obstetrics Department of Mymensingh Medical College Hospital from July 2009 to June 2010. After preservation in 10% normal saline, study was done in the department of Anatomy of Mymensingh Medical College. In this present study the mean±SD length of umbilical cord was found in different gestational age groups in Group A 63.00±5.40, Group B 63.69±8.80 and Group C 67.03±10.64cm and also observed that the mean length of umbilical cord increased with gestational age. The mean length of umbilical cord was maximum in Group C (67.03cm) and was minimum in Group A (63.00cm). The mean difference of length of umbilical cord among different groups was statistically not significant. Observed findings of this study were compared with those of western and Bangladeshi researches.

Purpose: The purpose of this study was to compare the sizes of the placenta and umbilical cord in women with natural pregnancy versus those undergoing in vitro fertilization (IVF)., Methods: Overall, 1610 cases of uncomplicated single pregnancies with vaginal delivery at ≥ 37 weeks of gestation were included in this study. The patients were divided into two groups: natural pregnancy group (n = 1453) and IVF pregnancy not including intracytoplasmic sperm injection (ICSI) treatment (n = 157). The groups were compared in terms of gestational week, maternal age, parity, maternal weight gain, prepregnancy maternal BMI, infant weight at birth, infant head circumference, placental weight, cross section of the placenta, cross section of the umbilical cord, insertion site of the umbilical cord, and umbilical cord length. Stepwise selection and multivariate logistic regression were used for statistical analysis to correct the result as an independent factor., Results: There was no difference in the size of the placenta and umbilical cord between women with natural pregnancy and with IVF, but the incidence of velamentous insertion of the cord was significantly increased in women with IVF pregnancy (adjusted odd ratio [AOR] 1.72, 95% confidence interval [CI] 1.08-2.72, p = 0.026)., Conclusions: Although there is no difference in placental weight and cord size, velamentous insertion of the umbilical cord increases in IVF pregnancy and needs careful observation during the delivery process.

Pregnancy complications may cause morphological changes and circulation defects in the placenta, which may lead to morbidity and mortality in fetuses and newborns. We investigated structural changes in the placenta and umbilical cord under various abnormal maternal conditions. Placenta and umbilical cord specimens were obtained from pregnant women during labor at 37 - 42 weeks gestation. Volumetric measurements were made for each placenta and umbilical cord using the Cavalieri method. Significant differences were observed for volumetric densities of total villi, syncytial knots, intervillous vessels and perivillous fibrin deposition. We observed particular increases in the volumetric parameters of the pre-eclampsia group compared to the other groups. The tunica media of the umbilical arteries was increased significantly with intrahepatic cholestasis.

Background: Vasa praevia (VP) is a rare phenomenon that is assumed to increase the risk of severe complications, including fetal death. Critical data on its incidence are lacking, so there is no rational basis for prenatal screening., Objectives: To review the literature on the incidence and risk indicators for VP., Search Strategy: We searched OVID MEDLINE, OVID EMBASE, the Cochrane Library and PubMed for case-control and cohort studies on incidence and risk indicators for VP., Selection Criteria: Two reviewers selected studies and scored their methodological quality., Data Collection and Analysis: We calculated the mean incidence of VP. We constructed 2 × 2 tables cross-classifying potential risk indicators against the incidence of VP to calculate common odds ratios and 95% confidence intervals, using the Mantel-Haenszel method., Main Results: We included 13 studies (two prospective cohort studies, ten retrospective cohort studies and one case-control study) reporting on 569 410 patients with 325 cases of VP. Based on ten included cohort studies providing information on the incidence, the mean incidence of VP was 0.60 per 1000 pregnancies. We identified five different risk indicators and markers for VP: second-trimester placenta praevia, conception by assisted reproductive technologies, a bilobed or succenturiate placenta, umbilical cord insertion in the lower third part of the uterus at first-trimester ultrasound and velamentous cord insertion. Almost 83% of the cases of VP had one or more risk indicators., Authors' Conclusions: In view of the low incidence, screening for VP in an unselected population is not advised. Targeted screening of women with one or more risk indicators as a part of routine mid-gestation scanning should be considered., Tweetable Abstract: Vasa praevia is more common in placenta praevia, conception by ART, velamentous cord insertion and bilobed placenta., (© 2015 Royal College of Obstetricians and Gynaecologists.)

Introduction: We established reference values for placental weight, birth weight, and fetal:placental weight ratio (FPR) (a possible index of placental functional efficiency) in monochorionic and dichorionic twin gestations., Methods: Placental weight, birth weight, and FPR in function of gestational age, cord insertion type and placental sharing were determined in 151 dye-injected diamniotic-monochorionic and 198 double-disc diamniotic-dichorionic twin placentas (25-39 weeks' gestation)., Results: As expected, FPR values increased with gestational age in both groups. Birth weights and placental weights of monochorionic twins >28 weeks' gestation were significantly lower than those of age-matched dichorionic twins. When stratified per placental weight, the birth weights and FPR values of monochorionic twins were overall lower than those of dichorionic twins within the same placental weight category. However, in the subset of monochorionic twins with small share in unevenly partitioned placentas, birth weights and FPR values per placental weight were similar to those of dichorionic twins, and significantly higher than those of monochorionic twins with larger share or even placental sharing. Cord insertion type did not correlate with birth weight or FPR values per placental weight in either twin type., Discussion: Reference values were generated for placental weight, birth weight and FPR in monochorionic and double-disc dichorionic twins. The generally lower FPR per placental weight in monochorionic twins compared with dichorionic twins is suggestive of inherently lower placental functional efficiency in monochorionic gestations. The mechanisms and clinical implications of the apparent differential modulation of FPR/efficiency in monochorionic twins according to placental partitioning remain to be determined., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Objective: To investigate the reconstruction of digital three-dimensional (3D) model of normal human placental vascular network based on MRI data in vitro., Methods: Six full term placentas were collected, casted with modified self-curing denture base resin and scanned by T1 e-THRIVE high resolution magnetic resonance imaging. MRI images were imported into Mimics 14.0 software for 3D reconstruction, and the 3D model was compared with placental vascular casting model., Results: (1) The placental vascular network could be obtained on MR 2D images. The 3D model were reconstructed successfully, which showed clear, realistic images. The 3D model could be zoomed and revolved from any direction to observe the branches of arteries and veins. (2) The umbilical vein and 2 umbilical arteries could be seen in the 3D model. In the root of the umbilical cord, the umbilical vein divided into 5-7 branches. While the 2 umbilical arteries anatomoses to form blood sinus and then devided into sub-branches. All the peripheral vessels ended in chorionic plate with abundant sub-branches. (3) When compared with the casting of placental arterial-venous vascular network, the morphology, structure, angle and trend of vessels in 3D model was consistent with the casting network., Conclusions: Reconstruction of digital 3D model of normal human placental vascular network based on MRI in vitro is a new and promising method for the study of placental vasculature. It has better vascular exposure, free rotation, radiation-free. It provides a promising base for the study of placental vasculature in vivo in the future.

The primo vascular system (PVS) has been observed in various animals such as mice, rats, rabbits, dogs, swine, and cow, but not in humans. In this work, we report on the observation of a human PVS on both the epithelial fascia and inside the blood vessels of the umbilical cord (UC). The main morphological characteristics of the primo vessels (PVs) and primo nodes (PNs) from the human UC were in agreement with those of the PVS in various animal organs, including the thicknesses and the transparency of the PVs, the sizes of the PNs, the broken-line arrangement of the rod-shaped nuclei, the sparse distribution of nuclei, and the presence of hollow lumens in the central inner parts of the PNs. It was rather surprising that the human PV was not thicker than the PVs from small animals. The difference between the PVS and blood/lymph vessels was confirmed using immunofluorescence staining of von Willebrand factor, CD31, LYVE-1, and D2-40. The positive expression of the PVS to proliferating cell nuclear antigen, a cell-proliferation marker, was consistent with the recent finding of very small embryonic-like stem cells in the PVS of mice., (Copyright © 2014. Published by Elsevier B.V.)

Birthweight at delivery is a standard cumulative measure of placental growth, but is a crude summary of other placental characteristics, such as, e.g., the chorionic plate size, and the shape and position of the umbilical cord insertion. Distributions of such measures across a cohort reveal information about the developmental history of the chorionic plate which is unavailable from an analysis based solely on the mean and standard deviation. Various measures were determined from digitized images of chorionic plates obtained from the pregnancy, infection, and nutrition study, a prospective cohort study of preterm birth in central North Carolina between 2002 and 2004. Centroids (geometric centers) and umbilical cord insertions were taken directly from the images. Chorionic plate outlines were obtained from an interpolation based on a Fourier series, while eccentricity (of the best-fit ellipse), skewness, and kurtosis were determined from the method of moments. Histograms of each variable were compared against the normal, lognormal, and Lévy distributions. Only a single measure (eccentricity) followed a normal distribution. All others followed lognormal or 'heavy-tailed' distributions for moderate to extreme deviations from the mean, where the relative likelihood far exceeded those of a normal distribution.

Introduction: Studies on developmental programming rely on various measures of size and form of the human placenta. Size and form are not independent of each other and covariation patterns were not determined systematically., Methods: Twenty-two morphologic parameters were determined on 418 placentas from uncomplicated singleton pregnancies. We determined (i) placenta weight and birth weight, (ii) form parameters such as diameters, thickness, roundness, and eccentricity of cord insertion, and (iii) shape variability by geometric morphometry. Geometric morphometry analyzes shape variability independent of size. We define the technical terms form and shape according to the language of geometric morphometry., Results: Placenta weight correlated with birth weight. The form parameters correlated variably with placenta weight and shape. Shape variability did not correlate with birth weight and placenta weight., Discussion and Conclusions: The correlation of placenta weight with birth weight stays a cornerstone of prenatal programming. Shape analysis shows that form parameters are hybrids of size and shape. Shape variability can be interpreted as an outcome of adaptation of a placenta to maternal factors and the associated uterine habitat. Correlation analysis of the whole data array provides a rigorous statistical frame to interpret published data and plan new studies., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Introduction: While the mean shape of human placenta is round with centrally inserted umbilical cord, significant deviations from this ideal are fairly common, and may be clinically meaningful. Traditionally, they are explained by trophotropism. We have proposed a hypothesis explaining typical variations in placental shape by randomly determined fluctuations in the growth process of the vascular tree. It has been recently reported that umbilical cord displacement in a birth cohort has a log-normal probability distribution, which indicates that the displacement between an initial point of origin and the centroid of the mature shape is a result of accumulation of random fluctuations of the dynamic growth of the placenta. To confirm this, we investigate statistical distributions of other features of placental morphology., Methods: In a cohort of 1023 births at term digital photographs of placentas were recorded at delivery. Excluding cases with velamentous cord insertion, or missing clinical data left 1001 (97.8%) for which placental surface morphology features were measured. Best-fit statistical distributions for them were obtained using EasyFit., Results and Discussion: The best-fit distributions of umbilical cord displacement, placental disk diameter, area, perimeter, and maximal radius calculated from the cord insertion point are of heavy-tailed type, similar in shape to log-normal distributions. This is consistent with a stochastic origin of deviations of placental shape from normal., Conclusions: Deviations of placental shape descriptors from average have heavy-tailed distributions similar in shape to log-normal. This evidence points away from trophotropism, and towards a spontaneous stochastic evolution of the variants of placental surface shape features., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Objective: The aims of the study were to establish reference ranges for placental length and thickness in a low-risk obstetric population and to assess the likelihood of a small for gestational age (SGA) neonate on the basis of placental length at 18-24 weeks' gestation., Methods: Placental length and thickness were measured by two sonographers in 520 singleton pregnancies. Uterine artery Doppler studies and a placental morphological assessment were also performed. Placental size was correlated with the birthweight centiles at delivery., Results: A placental length <10th centile between the gestational age of 18 and 24 weeks is a significant factor associated with SGA neonate [odds ratio (OR) = 2.8, 95% CL, 1.1-6.9]. An abnormal uterine artery Doppler is a significant factor for SGA neonate (OR = 3.4, 95% CL, 1.6-7.4). There was a weak relationship between cord insertion <2 cm from the placental margin and an SGA neonate (OR = 1.8, 95% CL, 0.4-8.2)., Conclusion: We have provided reference ranges for placental length and thickness from 18 to 24 weeks' gestation. A single measurement of placental length incorporated into the anatomy scan may assist in the early detection of a group at risk of delivering an SGA neonate., (© 2012 John Wiley & Sons, Ltd.)

Sensitivity of chorionic plate arteries to angiotensin II (AngII) is greatest at the placental periphery. Angiotensin converting enzyme (ACE) is central to the synthesis of AngII and is present in the placental vasculature. We measured vascular ACE activity/mg protein at 8-9 sites between the cord insertion and the periphery in 12 term placentae from normotensive, vaginally-delivered women. ACE increased from insertion to the periphery (P = 0.015); median ACE for each placenta was positively correlated with placental weight (P < 0.05) and placental:birthweight ratio (P < 0.02). We speculate that this may be related to fetal programming since placental:birthweight ratio is related to long-term health., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Background: Non-central cord insertion has been associated with diminished chorionic vascular distribution in singleton placentas. The choriovascular correlates of peripheral cord insertion in diamniotic-monochorionic twin placentas remain undetermined., Aim: To study the association between type of cord insertion and choriovascular distribution of both twin territories in diamniotic-monochorionic twin placentas., Design: A prospective cohort of 138 monochorionic placentas was examined at Women and Infants Hospital between 2009 and early 2011. Thirty-five cases (25%), including disrupted placentas, placentas from higher order multiples and placentas from pregnancies complicated by twin-to-twin transfusion syndrome, were excluded. The correlation between cord insertion type and superficial choriovascular distribution was studied in the remaining 103 dye-injected diamniotic-monochorionic placentas. Cord insertion was categorized as paracentral, marginal or velamentous. The choriovascular distribution of each individual twin territory was assessed by analysis of number and density (number per surface area) of perforating chorionic arteries (PCA)., Results: In contrast with singleton placentas, there was no correlation between cord insertion type and a twin's own choriovascular distribution in diamniotic-monochorionic placentas. However, a strong correlation was found between the choriovascular distribution of one twin and the cord insertion type of the opposite twin. For a twin with paracentral or marginal cord insertion, the PCA density was significantly higher if the co-twin had a velamentous cord insertion than if the co-twin had a paracentral cord insertion (P < 0.001 and P < 0.05, respectively). Similarly, the PCA density of a twin with velamentous cord insertion tended to be higher if the co-twin had a velamentous, rather than paracentral cord insertion (P = 0.09)., Conclusions: This is the first study to suggest that in diamniotic-monochorionic twin gestations, the choriovascular architecture correlates with the cord insertion type of the co-twin. In general, velamentous cord insertion is associated with expanded choriovascular distribution in the opposite twin territory. Our observations may reflect novel manifestations of twin interdependence in monochorionic pregnancies., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objective: The purpose of this study was to evaluate the impact of noncentral placental cord insertion on birthweight discordance in twins., Study Design: We performed a multicenter, prospective trial of twin pregnancies. Placental cord insertion was documented as central, marginal, or velamentous according to a defined protocol. Association of the placental cord insertion site with chorionicity, birthweight discordance, and growth restriction were assessed., Results: Eight hundred sixteen twin pairs were evaluated; 165 pairs were monochorionic, and 651 pairs were dichorionic. Monochorionic twins had higher rates of marginal (P = .0068) and velamentous (P < .0001) placental cord insertion. Noncentral placental cord insertion was more frequent in smaller twins of discordant pairs than control pairs (29.8% vs 19.1%; P = .004). Velamentous placental cord insertion in monochorionic twins was associated significantly with birthweight discordance (odds ratio, 3.5; 95% confidence interval, 1.3-9.4) and growth restriction (odds ratio, 4; 95% confidence interval, 1.1-14.3)., Conclusion: Noncentral placental cord insertion contributes to birthweight discordance in monochorionic twin pregnancies. Sonographic delineation of placental cord insertion may be of value in antenatal assessment of twin pregnancies., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Background: The position of the placental cord insertion, its shape and cord coiling are thought to be associated with perinatal outcome. This study derives indices describing the relationship of cord insertion to the placental centre, the shape of the placenta and cord coiling in placentas from unselected term pregnancies. Further, we investigate these indices in pregnancies affected by pre-eclampsia (PET), pregnancy induced hypertension (PIH), gestational diabetes mellitus (GDM) and delivery of a small for gestational age (SGA) baby., Design/methodology: Eight hundred and sixty one unselected women with singleton pregnancy delivering at 37-42 weeks were prospectively recruited to this study. Placental axes and their relationship with the cord insertion were measured using digital photography and proprietary software. From these, the cord centrality (distance of umbilical cord insertion from the centre) and placental eccentricity (deviation of the placental shape from circular) were derived. The cord coiling index (number of coils in the cord divided by the length of cord in cm) was also calculated from manual measurements., Results: The mean value of cord centrality index was 0.36 (SD = 0.21) and of placental eccentricity 0.49 (SD = 0.17). Left direction of umbilical cord coiling was more common than right (79% vs 16.4%) The mean cord coiling index was 0.20 (SD = 0.09) coils/cm. The indices were constant between 37 and 42 weeks and were no different in the non-affected population compared to women with pre-eclampsia (n = 17), PIH, (n = 27), GDM (n = 38) or delivery of an SGA baby (n = 54)., Conclusion: The cord centrality index that we derive suggests that the cord insertion is most commonly 'off centre', and eccentricity index that the placental shape is elliptical. Therefore, contrary to widely held belief, the cord does not normally insert centrally nor is the placenta normally round in shape. There is a preponderance of left sided coiling. There was no difference for any of the indices between the non-affected pregnancies and pregnancies affected by pre-eclampsia, PIH, GDM and SGA., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Unlabelled: Twin pregnancies are regarded as high risk pregnancies. It results from the possibility of occurrence of numerous complications both like the ones in singleton pregnancies and those characteristic for multiple pregnancy only. The complication occurring exclusively in multiple pregnancies is discordant intrauterine growth of the fetuses., The Aim: a response to the question if there a relationship between the type of afterbirth and twin birth weight discordance., Material and Methods: Material of the research consisted of 186 afterbirths derived from successful twin pregnancies. In the study the following were taken into consideration: evaluation of placenta/placentas types (mono- or dichorionic), place of umbilical cords insertion, and differences concerning birth weight of newborns., Results: The birth weight discordance of less than 10% (l0) in the twins was noted in 52.7% of pregnancies (n=98), discordance of 10-20% (II degree) was observed in 30.1% (n=56), and over 20% (III degree) in 17.2% (n=32). The birth weight discordance of the third degree was observed significantly more often in dichorionic diamniotic pregnancies with fused placentas. The discordance of third degree (>20%) occurred in 38.2% of female-male pairs, in 35.7% of female-female ones and in 24.3% of male-male pairs. In case of coexistence of both normal umbilical cord insertions the birth weight discordance of third degree occurred in 17.8% of pregnancies, in case of co-occurrence of the abnormal insertion with the normal one--in 21.8% of cases, and in case of the two abnormal insertions--in 10.5%. No statistically significant differences were found., Conclusions: There is a relationship between the type of afterbirth and birth weight in twins. The largest birth weight discordance between fetuses occurs in the following cases: in dichorionic pregnancies with fused placental discs, in case of co-existence of abnormal and normal umbilical cord insertions and in female-male pair of twins.

Goals: Fetal growth depends on placental growth; the fetoplacental weight ratio (FPR) is a common proxy for the balance between fetal and placental growth. Male and female infants are known to have differing vulnerabilities in fetal life, during parturition and in infancy. We hypothesized that these differences may be paralleled by differences in how birth weight (BW) and the fetoplacental weight ratio (FPR) are affected by changes in placental proportions., Materials and Methods: Placental proportion measures (disk shape, larger and smaller chorionic diameters, chorionic plate area calculated as the area of an ellipse with the 2 given diameters, disk thickness, cord eccentricity and cord length) were available for 24,601 participants in the Collaborative Perinatal Project delivered between >34 and <43 completed weeks. The variables were standardized and entered into multiple automated regression splines (MARS 2.0, Salford Systems, Vista CA) to identify nonlinearities in the relationships of placental growth measures to BW and FPR with results compared for male and female infants., Results: Changes in chorionic plate growth in female compared to male infants resulted in a greater change in BW and FPR. The positive effects of umbilical cord length on BW reversed at the mean umbilical cord length in females and at +0.08 SD in male infants., Conclusions: Female infants' BW and FPR are each more responsive to changes in placental chorionic plate growth dimensions than males; this may account for greater female resilience (and greater male vulnerability) to gestational stressors. The effect of umbilical cord length on FPR may be due to longer cords carrying greater fetal vascular resistance. Again male fetuses show a higher "threshold" to the negative effects of longer cords on FPR.

To study placental characteristics in relation to perinatal outcome in 150 pairs of monochorionic diamniotic (MCDA) twins. Between January 1998 and January 2007 150 pairs of MCDA twins were delivered in the University Medical Center, Utrecht, The Netherlands. Mortality, neonatal morbidity and birth weight discordancy were studied in relation to type of anastomoses, type and distance between cord insertions and placental sharing. From 14 weeks onwards, there were 45 (15.0%) perinatal deaths. We found no clear relationship between perinatal mortality and type of anastomoses, distance between cord insertions and placental sharing. Perinatal mortality was significantly increased in the presence of velamentous cord insertion (OR 3.65, 95% CI 1.83-7.28). Data concerning neonatal morbidity were similar. TTTS occurred predominantly in the presence of AV-anastomoses without compensating superficial AA-anastomoses (p=0.005) and occurred more frequently in the presence of velamentous cord insertion (OR 1.79, 95% CI 0.94-3.44). Twins with unequal shared placentas had significantly more often severe birth weight discordancy, although only in the presence of AA-anastomoses (OR 4.09, 95% CI 1.74-9.63). If AA-anastomoses were absent in the unequally shared placenta, there was no relation between severe birth weight discordancy and unequal sharing of the placenta (OR 1.06, 95% CI 0.08-13.52). In MCDA twins, placental characteristics determine perinatal outcome, occurrence of TTTS and fetal growth. Prenatal identification of these characteristics by ultrasound may alter counselling and intensity of pregnancy surveillance.

This study was designed to establish the morphological features of the placenta of the Martina Franca jenny. Ten placentas were harvested at the time of foal delivery and examined both for gross and histological characteristics. The following factors were determined: the total weight and volume of the placenta and its components, the surface area of the allantochorion, umbilical cord length and site of insertion, and the diameter of the umbilical cord vessels and vascular pattern type. The weight of the placenta was similar to previously reported for ponies, and represented 12% of foal birth weight. Umbilical cord length was similar to that in the horse but longer than in the pony, while cord weight was intermediate between the two. In a histological examination, numerous strong villi were observed at sites corresponding to the non-pregnant and pregnant horn and uterine body. No villi were detected in the area overlying the cervical star. Despite obvious similarities between the donkey and horse placenta, specific morphological features do exist, and are possibly related to the differences in length of gestation.

To elucidate the morphological differences between placentas from normal and cloned cattle pregnancies reaching term, the umbilical cord, placentomes and interplacentomal region of the fetal membranes were examined macroscopically as well as by light and scanning electron microscopy. In pregnancies established by somatic nucleus transfer (NT), the umbilical cord and fetal membranes were edematous. Placentomal fusion was common, resulting in increased size and a decreased number of placentomes. Extensive areas of the chorioallantoic membrane were devoid of placentomes. An increased number of functional or accessory microcotyledons (<1 cm) were present at the maternally oriented surface of fetal membranes. Extensive areas of extravasated maternal blood were present within the placentomes and in the interplacentomal region. The crypts on the caruncular surface were dilated and accommodated complexes of more than one primary villus, as opposed to a single villus in non-cloned placentae. Scanning electron microscopy of blood vessel casts revealed that there was also more than one stem artery per villous tree and that the ramification of the vessels failed to form dense complexes of capillary loops and sinusoidal dilations as in normal pregnancies. At the materno-fetal interface, however, the trophoblast and uterine epithelium had normal histology. In conclusion, the NT placentas had a range of pathomorphological changes; this was likely associated with the poor clinical outcome of NT pregnancies.

A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing two distinct families. The umbilical cord branched to supply a bilobed allantoic sac. Small blood vessels and smooth muscle bundles were found within the stroma of the cord. Foci of squamous metaplasia occurred in the allanto-amnion and allantochorion. The interhemal membrane of the placenta was of the epitheliochorial type. Two different types of trophoblastic epithelium were seen. Most was of the simple columnar type and indented by fetal capillaries. However, there were also areolar regions with tall columnar trophoblast and these were more sparsely supplied with capillaries. The endometrium was well vascularised and richly supplied with actively secreting glands. These findings are consistent with the current view that Cetacea are nested within Artiodactyla as sister group to the hippopotamids.

Introduction: Even though placentas from assisted reproduction programs often differ from placentas of women who conceived naturally, they are rarely examined. The aim of our investigation was to determine some gross characteristics of placentas of women who conceived with assisted reproduction., Material and Methods: We examined 30 placentas from an assisted reproduction program (20 from in vitro fertilization and 10 from intrauterine insemination) and 30 placentas of women who conceived naturally. All women were age matched. All the women were at term., Results: The mean weight of placentas from assisted reproduction program was 573 g and of those after natural conception--582.67g. The mean length of the umbilical cords was 64.3cm after assisted reproduction and 66.3cm after natural conception. The mean placenta thickness after assisted reproduction was 2,22 cm and after natural conception 2.28 cm. Eight placentas of the study group had a marginal insertion of the umbilical cord, which lead to a statistically significant difference when compared to placentas of women who conceived naturally: chi-square = 7.07; p>0.01., Discussion: Marginal cord insertion into the placenta after assisted reproduction is also often described in the literature (as a possible "consequence" of embryo-transfer)., Conclusion: There were no statistically significant differences in the mean weight and dimensions of placentas, length of the umbilical cord, gross pathological features of placentas and cords, mean birth weight of babies and placental/fetal ratios between women from assisted reproduction program and those who conceived naturally.

Several recent publications have focused on the association between the occurrence of twin-to-twin transfusion syndrome (TTTS) in diamniotic-monochorionic twins and the presence of a number of selected anatomic placental characteristics (distribution of vascular territory, cord insertion, type and number of inter-twin anastomoses). In contrast, the potential importance of the vascular distribution patterns of the individual twins remains to be elucidated. Based on its gross architectural distribution pattern, chorionic vasculature is traditionally described as disperse, magistral or mixed. The aim of this study was (1) to determine the relative prevalence of these vascular distribution patterns in monochorionic twin placentas, and (2) to correlate these patterns with the presence of TTTS and known anatomic placental features linked to TTTS. The placentas of 89 consecutive diamniotic-monochorionic twins (15 with TTTS, 74 without TTTS), examined at Women and Infants Hospital, were studied. Disperse vascular patterns were seen in 53% of twins, and magistral or mixed patterns in 47%. The prevalence of magistral/mixed vascular patterns was significantly higher in TTTS gestations than in non-TTTS gestations (60% versus 44%, P<0.05) and, in TTTS gestations, much higher in donor twins than in recipient twins (87% versus 33%, P<0.005). A strong association was found between the presence of magistral/mixed patterns and marginal/velamentous cord insertion, low number of inter-twin anastomoses, and uneven distribution of the vascular territories. These findings suggest that the magistral/mixed vascular distribution pattern may represent an important placental architectural feature contributing to the complex pathophysiology of TTTS.

Triage is the sorting and allocation of treatment according to a system of priorities in order to maximize treatment. Placental triage promptly after delivery of the placenta, with documentation of the findings in the medical record, only takes a few minutes, and allows for the identification of abnormal placentas to be submitted for detailed gross and microscopic pathology examination. It requires familiarity with normal gross placental anatomy and variations of normal, and the development of a systematic procedure for comprehensive examination of the placental disk as a whole, the umbilical cord, the extraplacental membranes, the fetal surface, the maternal surface, and the parenchyma. This article provides a systematic approach to gross examination of the placenta. It also reviews the clinical and legal impact of placenta examination, and suggests procedures that will optimize the information available in the placenta.

This paper reviews the principle features of human placenta structure and development, and it highlights areas of needed future research. The complexity of placental histology is discussed and comparison of the human placenta with other mammalian taxa is made. A more widespread appreciation of the value of studying this challenging organ and a more profound understanding of the regulation of the placental transport functions is advocated. Simple, routine examination of the placenta should be resurrected.

Neonatal and placental factors and compartment volumes of placental parenchyma in relation to variations of cord insertions in normal human placentae were examined. The results of our investigation suggest that the mode of umbilical cord insertion has no significant effect on examined components. Stated differences are probably the effect of biological variations during normal placental and fetal development.

A study on the anthropometric indices of 3835 singleton newborn babies was conducted over a four months period at Sree Avittom Thirunal Hospital, Trivandrum. Of these, 1921 (50.1%) were male babies and 1914 (49.9%) were female babies. The majority of infants (43%) were born to the middle socio-economic groups and the mean birth weight of babies was high among the high-income groups. Five hundred and ninety six (15.5%) babies weighed less than 2500 g; of these 121 (20.2%) were preterm and 477 (79.8%) were full term. The prevalence of low birth weight (LBW) was high (22.0%) among the mothers aged between 15 and 19 years. There was a significant difference (p < 0.001) in the mean birth weight (BW) of term male and female babies but there was no significant differences in their body length, head circumference and cord length. The mean ponderal index of term newborn babies was 2.3 g/cm3. The mean placental weight of LBW term and preterm babies was less than that of the corresponding normal weight babies. The birth weight of babies was directly proportional to their placental weight.

The paper presents some salient aspects of a study on the placentation of camel at gross, light and electron microscopic levels. The study involved factors analysis on five pregnant uteri from camel slaughter house in Yazd, Iran. The experimental observations confirmed that unlike other animals, in camel, the fetus only developed in the left horn of the uterus. Based on the distribution type of the chorionic villi, in camel, similar to horse, the placenta was found to be in diffused form. At light microscopic level, the results revealed six layers between the fetal and maternal blood. From this it inferred that camel's placenta was also of epitheliochorial form. The detailed examination further showed that similar to cow and sheep umbilical cord in camel was also limited to the amniotic sac but it contained two arteries, two veins and one urachus. Little amount of elastic fibers were also observed in the histological and electron microscopical sections. At the electron microscopic level, both binucleated and mononucleated cells in trophoblastic layer were confirmed.

We investigated whether variations in mode of attachment of umbilical cords and vessels coincided with differences in maternal haemoglobin genotype and neonatal factors or placental micro-volumetric composition. The incidence of placentae with marginally inserted cords, or those in which umbilical vessels separated prior to insertion, was not statistically different in samples from sickle cell patients having haemoglobin-SS and haemoglobin-SC genotypes, as compared with haemoglobin-AA controls. Results obtained from analysis of variance (ANOVA) suggest that the mode of insertion (status) of umbilical vessels may have clinical significance, because it produced differences in the main effects associated with neonatal gestational age, placental weight, and placental index. Point counting stereology was employed to estimate the microscopic compartment volumes of placentae prior to an assessment of statistical association between the data obtained and the status of umbilical vessels and maternal haemoglobin genotype. Furcate placentae (with separated umbilical vessels) had statistically greater than normal volumes of villi, villous trophoblast, and syncytial knots. We deduce that furcate placentae are prone to early delivery, because they are heavier, having more voluminous villi with more trophoblast and syncytial knots than controls.

Almond glycopeptidase is an enzyme which cleaves specifically beta-aspartylglucosylamine linkages in glycoproteins with asialo-carbohydrate moieties. With this enzyme, it was possible to demonstrate the localization of asparagine-linked oligosaccharides in glycoproteins of human placenta and umbilical cord tissues. In these tissues, the oligosaccharides were shown to react positively for a series of histochemical procedures for neutral complex carbohydrates such as periodic acid-Schiff (PAS), peroxidase-labelled Ricinus communis agglutinin-I-diaminobenzidine (PO-RCA-DAB) and concanavalin A-peroxidase-diaminobenzidine (Con A-PO-DAB). The asparagine-linked carbohydrates were localized in the placental villi, blood vessels and perivascular tissues and the umbilical cord blood vessels and matrix. The results of previous biochemical analyses performed upon the same tissues (Takahashi et al., 1981) have corroborated the results of the histochemical studies. The present results appear to substantiate the usefulness of almond glycopeptidase for the histochemical demonstration of the particular oligosaccharides of glycoproteins in tissues in general.

Neurohistochemical techniques were used to determine the distribution of adrenergic and cholinergic nerves in the human placenta and the umbilical cord adjacent to the chorion. These morphologic studies demonstrate the absence of neural elements in these sites. The significance of these findings to the placental innervation controversy is discussed.

The site of the insertion of the umbilical cord into the placenta was determined in 940 consecutive term infants. No relation was found between birth weight and whether the cord was inserted centrally, eccentrically or marginally.

The body weight of newborns, the weight of placenta, the length of umbilical cord and the content of urobilinogen, gulcose, protein, pH, keton body in amniotic fluid were investigated with samples from 16 litters of beagles. The mean body weight of newborn, weight of placenta and length of umbilical cord were 258.0 +/- 44.6 g (85 samples), 48.5 +/- 8.5 g (85 samples) and 11.0 +/- 2.7 cm (52 samples), respectively without any sex difference. The significant correlation were recognized between the weight of placenta and the body weight of newborn, between the length of umbilical cord and the body weight of newborn and between the weight of placenta and the length of umbical cord (P less than 0.01).

We examined the gross and microscopic anatomy of placental tissues and umbilical cords from six species representing the three living families of the Suina. These species included, of the Suidae, the wart hog (Phacochoerus aethiopicus), the giant forest hog (Hylochoerus meinertzhageni), the domestic pig (Sus scrofa), and the banded pig of Malaysia (Sus scrofa vittatus); of the Tayassuidae, the white-lipped peccary (Tayassu pecari); of the Hippopotamidae, the hippopotamus (Hippopotamus amphibius) and the pigmy hippopotamus (Choeropsis liberiensis). All these species have a diffuse epitheliochorial placenta. The chorion is folded, and has on its surface rows of shallow ripples or villi, interrupted by round, oval or irregularly shaped areolae. Placental capillaries indent the epithelial layer covering the tops and sides of the interareolar villi, but not the columnar cell layer lying in the troughs between these villi or covering the areolae. Cuboidal cells cover the crests of the villi in the Suidae and Hippopotamidae, whereas in the Tayassuidae the epithelium is syncytial in appearance. The similarities in placental structure between the six species are more apparent than the differences. Suidae and Tayassuidae have smooth umbilical cords containing two arteries and one vein; those of the Hippopotamidae are pustule-encrusted and contain two arteries and two veins.

In 429 placentae, measurements were made of weight, diameter, shape, eccentricity of the cord and weight and length of the cord, and the results were compared with Apgar score of the infant at birth and its standardized birth weight. There was no evidence that cord eccentricity, placental shape or "thickness", or the dimensions of the cord had any significant relation to the growth of the fetus or its condition at birth. The value of routine recording of crude measurements and qualitative assessments of the placenta in case notes is questioned.