Placental Biometry Research Articles

Serial placental profile of women with preeclampsia and normal outcome: Placental biometry/ uterine artery PI a promising marker

Serial placental profile of women with preeclampsia and normal outcome: Placental biometry/ uterine artery PI a promising marker

Reference Ranges of 2-Dimensional Placental Biometry and 3-Dimensional Placental Volume between 11 and 14 Weeks of Gestation.

The purpose of this study was to provide gestational age (GA) specific reference ranges for 2-dimensional (2D) placental biometry and 3-dimensional (3D) placental volume between 11 and 14 weeks of gestation. Placental biometry including 2D and 3D variables was calculated in 1142 first-trimester singleton pregnancies with non-complicated outcome between September 2016 and February 2020. Ultrasound datasets were obtained at the time of the first-trimester ultrasound, and 2D basal plate (BP), chorionic plate (CP), placental thickness (PT), and 3D placental volume (PV) were measured following a standardized methodology. Reference ranges for each variable were calculated according to GA and crown-rump-length (CRL). A total of 1142 uncomplicated pregnancies were considered for analysis. All placental measurements increased significantly between 11 and 14 weeks, especially for PT (39.64%) and PV (64.4%). Reference ranges were constructed for each 2D and 3D first-trimester placental variable using the best-fit regression model for the predicted mean and SD as a function of GA and CRL. Reference ranges of 2D placental biometry and 3D placental volume between 11 and 14 weeks of gestation were constructed, generating reference values. Placental biometry showed a progressive increase during the first trimester. This highlights the importance of using reference range charts according to GA.

Placental biophysical model for prediction of early onset fetal growth restriction in first and second trimester of pregnancy: A prospective cohort study

IntroductionTo assess the placental biometry, placental biomarkers and uterine artery Doppler in each trimester of pregnancy for prediction of early-onset fetal growth restriction (EO FGR). MethodsIn this prospective cohort study placental biometry; biomarkers PAPP-A, sFLT-1, and PlGF along with the uterine artery blood flow evaluation was done serially at 11–14, 20–24 and 28–32 weeks of gestation. The above parameters were compared between women with early onset FGR and controls. ResultsOut of 1008 fully followed cases, the small for gestational age fetuses were 227/1008 (22.5 %), and EO FGR were 84/1008(8.3 %).The placental length, volume, and PlGF levels were significantly lower, whereas the uterine artery PI(Ut PI) was significantly higher at all time points among cases. The sFLT-1 level showed a significant increase among cases, whereas it decreased among controls from the first to the second trimester. The detection rate using PV/UtA PI was 60 % in the first trimester and 66.7 % in the second trimester at 30 % FPR. ConclusionThe PV/Ut PI in first and the second trimester was a good marker for the prediction of pregnancies at increased risk of developing EO FGR.

A real-life prospective blinded evaluation of placental biometry and macroscopic morphology from 1008 unselected consecutive pregnancies

IntroductionThe study of the macroscopic appearance of the placenta may represent a useful tool to understand the pathophysiology of adverse pregnancy outcomes. The aim of this study was to evaluate biometry and morphology of placentas in relation to maternal, neonatal and pregnancy course characteristics. MethodsClinical and placental data (biometry and macroscopic features of chorionic disk and adnexa) from unselected consecutive singleton pregnancies were recorded at the same Institution. Placental efficiency was approximated as ratio between fetal and placental weight (FPR). The total population was grouped according to the presence of any maternal comorbidity or pregnancy complication (group 1), neonatal complications diagnosed only at birth (2) and absence of any comorbidity (3). Multi-adjusted general linear and logistic regression models were performed to analyze associations between groups and placental biometry and morphology. ResultsThe study population counted 1008 pregnancies: 576 (57.2 %) classified as group 1, 76 (7.5 %) as group 2 and 356 (35.3 %) uncomplicated controls (group 3). In multivariate models adjusted for confounding factors, no significant differences in placental biometry and macroscopic features were observed among the three groups. Maternal BMI was significantly associated with higher placental and birth weight and lower FPR; moreover FPR was significantly higher in pregnancies carrying males compared to female neonates. DiscussionMaternal comorbidity or pregnancy disease was not associated with significant changes in placental macroscopic biometry and morphology. Conversely, maternal pregestational BMI and fetal sex impact on placental biometry and efficiency, suggesting different intrauterine adaptations in obese mothers and in male and female fetuses.

Ultrasound Placental Remodeling Patterns and Pathology Characteristics in Patients with History of Mild SARS-CoV-2 Infection during Pregnancy

Introduction: This research aims to describe a progressive pattern of ultrasound placental remodeling in patients with a history of SARS-CoV-2 infection during pregnancy. Materials and Methods: This was a longitudinal, cohort study which enrolled 23 pregnant women with a history of former mild SARS-CoV-2 infection during the current pregnancy. Four obstetricians analyzed placental ultrasound images from different gestational ages following COVID infection and identified the presence and degree of remodeling. We assessed the inter-rater agreement and the interclass correlation coefficients. Pathology workup included placental biometry, macroscopic and microscopic examination. Results: Serial ultrasound evaluation of the placental morphology revealed a progressive pattern of placental remodeling starting from 30-32 weeks of gestation towards term, occurring approximately 8-10 weeks after the SARS-CoV-2 infection. Placental changes-the "starry sky" appearance and the "white line" along the basal plate-were identified in all cases. Most placentas presented normal subchorionic perivillous fibrin depositions and focal stem villi perivillous fibrin deposits. Focal calcifications were described in only 13% of the cases. Conclusions: We identified two ultrasound signs of placental remodeling as potential markers of placental viral shedding following mild SARS-CoV-2. The most likely pathology correspondence for the imaging aspect is perivillous and, respectively, massive subchorionic fibrin deposits identified in most cases.

Developmental Ultrasound Characteristics in Guinea Pigs: Similarities with Human Pregnancy.

Biometrical and blood flow examinations are fundamental for assessing fetoplacental development during pregnancy. Guinea pigs have been proposed as a good model to study fetal development and related gestational complications; however, longitudinal growth and blood flow changes in utero have not been properly described. This study aimed to describe fetal and placental growth and blood flow of the main intrauterine vascular beds across normal guinea pig pregnancy and to discuss the relevance of this data for human pregnancy. Pregnant guinea pigs were studied from day 25 of pregnancy until term (day ~70) by ultrasound and Doppler assessment. The results were compared to human data from the literature. Measurements of biparietal diameter (BPD), cranial circumference (CC), abdominal circumference, and placental biometry, as well as pulsatility index determination of umbilical artery, middle cerebral artery (MCA), and cerebroplacental ratio (CPR), were feasible to determine across pregnancy, and they could be adjusted to linear or nonlinear functions. In addition, several of these parameters showed a high correlation coefficient and could be used to assess gestational age in guinea pigs. We further compared these data to ultrasound variables from human pregnancy with high similarities. BPD and CC are the most reliable measurements to assess fetal growth in guinea pigs. Furthermore, this is the first report in which the MCA pulsatility index and CPR are described across guinea pig gestation. The guinea pig is a valuable model to assess fetal growth and blood flow distribution, variables that are comparable with human pregnancy.

Placental Development and Physiological Changes in Pregnant Ewes in Silvopastoral and Open Pasture Systems during the Summer.

This study aimed to analyze the reproductive and physiological changes in ewes subjected to heat stress during pregnancy at UTFPR-Brazil. Twenty-four pregnant crossbred ewes were kept in a silvopastoral system (SP) or an open pasture system (OP) throughout the final trimester of pregnancy. Both systems were stressful, but the SP system had lower air temperature than the OP system (26.0 ± 0.38 and 26.9 ± 0.41 °C, respectively; p = 0.0288). Moreover, the radiant thermal load of the two groups presented a difference of 34 Wm-2 (p = 0.0288), and the grass temperature was also lower in the SP system compared to that in the OP system (23.4 ± 0.37 and 25.6 ± 0.44 °C, respectively; p = 0.0043). The respiratory and heart rates of animals from the OP group were higher than those from the SP group (p < 0.001), but no difference was observed in the mobilization of white blood cells (p = 0.4777), and the neutrophil count was only affected by time (p < 0.0001). As regards placental biometry, placentas in twin pregnancies had a greater membrane area (p = 0.0223), but no differences between the systems were observed in placental weight (p = 0.1522) and the number of cotyledons (p = 0.5457). We concluded that the type of rearing system used affects the thermal comfort of pregnant ewes, and that an SP system can offer more amenable microclimatic conditions, which result in greater comfort for the ewes.

Placental pathology in COVID-19 affected pregnant women: A prospective case-control study

IntroductionDuring pregnancy, SARS-CoV-2 infection may cause an abnormal development of the placenta, thus influencing maternal and fetal outcomes. Few studies have reported data on placental morphology and histology in infected pregnant patients, although not compared with carefully matched controls. The aim of this study is to compare placental morphology and histology of pregnant women affected by SARS-CoV-2 to non-infected controls. MethodsThis is a prospective multicenter case-control study on 64 pregnant women affected by SARS-CoV-2 who delivered at term or late-preterm. Data were collected about pregnancy course, maternal and fetal outcomes, placental biometry and macro- and microscopical morphology. 64 not-infected women were identified as controls, matched by age, body mass index and ethnicity. ResultsCases and controls had similar fetal and maternal outcomes. No significant differences were observed in placental macro- or microscopical morphology between the two groups. In the cases treated with antivirals, chloroquine, LMWH or antibiotics, placentas were heavier but not more efficient than the non-treated, since the fetal/placental weight ratio did not differ. Moreover, delayed villous maturation was more frequent in treated women, although not significantly. The newborns whose mothers received oxygen therapy as treatment had higher levels of umbilical cord pO₂ at birth. DiscussionIn this prospective case-control study, SARS-CoV-2 infection during the third trimester did not influence placental histological pattern. Pharmacological and oxygen therapy administered to women affected by this viral infection could impact maternal and fetal outcomes and be associated to placental histological alterations.

VP51.06: Inter‐ and intraobserver agreement in first trimester ultrasound evaluation of placental biometry

VP51.06: Inter‐ and intraobserver agreement in first trimester ultrasound evaluation of placental biometry

Inter- and Intraobserver Agreement in First Trimester Ultrasound Evaluation of Placental Biometry

Objective: The aim of this study was to assess the clinical applicability of a new analytical software program by determining the inter- and intraobserver agreement for 2D placental biometry and three-dimensional (3D) placental volume (PV) in the first trimester. Methods: A prospective study of 25 singleton pregnancies between 11 and 14 weeks was conducted. 3D datasets were captured, and PV was estimated using the Phillips QLAB GI3DQ ultrasound quantification software. The basal plate (BP), chorionic plate (CP), placental thickness (PT), and the free uterine surface (FUS) area not occupied by placenta were considered for 2D biometry evaluation. Each variable was measured in 2 orthogonal planes with mean values used for the analysis. Intra- and interobserver agreement was evaluated. Results: Intraobserver agreement for both 2D and 3D measurements was high, particularly for the PV and PT (interclass correlation coefficient [ICC] 0.989 [95% confidence interval (CI) 0.97–0.99] and ICC 0.936 [95% CI 0.86–0.97], respectively). Interobserver agreement was good for the PV (ICC 0.963 [95% CI 0.91–0.98]), PT (ICC 0.822 [95% CI 0.63–0.91]), and CP (ICC 0.708 [95% CI 0.44–0.86]), but moderate for BP and FUS. Conclusions: PV, PT, and CP are reproducible measurements to evaluate first trimester placental biometry. Further research is needed to assess the clinical utility of these variables as predictors of poor obstetric outcomes.

Minimally interactive placenta segmentation from three-dimensional ultrasound images.

Purpose: Placental size in early pregnancy has been associated with important clinical outcomes, including fetal growth. However, extraction of placental size from three-dimensional ultrasound (3DUS) requires time-consuming interactive segmentation methods and is prone to user variability. We propose a semiautomated segmentation technique that requires minimal user input to robustly measure placental volume from 3DUS images. Approach: For semiautomated segmentation, a single, central 2D slice was manually annotated to initialize an automated multi-atlas label fusion (MALF) algorithm. The dataset consisted of 47 3DUS volumes obtained at 11 to 14 weeks in singleton pregnancies (28 anterior and 19 posterior). Twenty-six of these subjects were imaged twice within the same session. Dice overlap and surface distance were used to quantify the automated segmentation accuracy compared to expert manual segmentations. The mean placental volume measurements obtained by our method and VOCAL (virtual organ computer-aided analysis), a leading commercial semiautomated method, were compared to the manual reference set. The test-retest reliability was also assessed. Results: The overlap between our automated segmentation and manual (mean Dice: , median: 0.831) was within the range reported by other methods requiring extensive manual input. The average surface distance was . The correlation coefficient between test-retest volumes was , and the intraclass correlation was . Conclusions: MALF is a promising method that can allow accurate and reliable segmentation of the placenta with minimal user interaction. Further refinement of this technique may allow for placental biometry to be incorporated into clinical pregnancy surveillance.

1040: Measuring placental biometry does not improve prediction of placental dysfunction in a high-risk pregnancy cohort

1040: Measuring placental biometry does not improve prediction of placental dysfunction in a high-risk pregnancy cohort

Effects of dietary arginine supplementation in pregnant mares on maternal metabolism, placental structure and function and foal growth

Foals born to primiparous mares are lighter and less mature than those born to multiparous dams. Factors driving this difference are not totally understood. Using 7 multiparous and 6 primiparous standardbred mares, we demonstrated that, in late gestation, primiparous mares were less insulin resistant compared to multiparous mares, and that their foals had reduced plasma amino-acid concentrations at birth compared to foals born to multiparous mares. Vascular development, as observed through structure and gene expression, and global DNA methylation were also reduced in primiparous placentas. Another group of 8 primiparous mares was orally supplemented with L-arginine (100 g/day, 210d to term). L-arginine improved pregnancy-induced insulin resistance and increased maternal L-arginine and L-ornithine plasma concentrations but foal plasma amino acid concentrations were not affected at birth. At birth, foal weight and placental biometry, structure, ultra-structure and DNA methylation were not modified. Placental expression of genes involved in glucose and fatty acid transfers was increased. In conclusion, maternal insulin resistance in response to pregnancy and placental function are reduced in primiparous pregnancies. Late-gestation L-arginine supplementation may help primiparous mares to metabolically adapt to pregnancy and improve placental function. More work is needed to confirm these effects and ascertain optimal treatment conditions.

321. Is small placental biometry independent of increased uterine artery Doppler resistance for the prediction of fetal growth restriction?

Introduction Fetal growth restriction (FGR) is associated with significant perinatal morbidity and mortality. Therefore, early prediction of FGR remains an important research question. 2-dimensional placental biometry offers an affordable and readily available adjunct to uterine artery (UtA) Doppler and fetal biometry measurement in the prediction of FGR. Objective To determine if there is an association between placental biometry and birthweight and explore its relationship with UtA Doppler. Methods This was a retrospective study of 820 pregnant women presenting to the high-risk research clinics at a tertiary centre. Women underwent a “placental screen” at 22–24 weeks’ gestation, during which UtA Dopplers, fetal and placental biometry were measured. FGR was defined as birthweight Results 74/820 pregnancies were complicated by FGR. Placental size was significantly smaller in FGR pregnancies and correlated with birthweight centile (p Discussion Smaller placental biometry independently predicts FGR although there is a relationship with increased UtA PI. This suggests that an alternate pathological process causing reduced placental growth aside from reduced placental perfusion might be present in some cases of FGR. Research exploring the relationship between placental size and fetal and neonatal growth is required to investigate this further.

Maternal parity affects placental development, growth and metabolism of foals until 1 year and a half

Primiparous mares are known to produce smaller foals than multiparous mares. This difference seems to be partly explained by the reduced exchange surface and volume of the placental villi in primiparous compared to multiparous placentas. The effect of maternal parity on foals' post-natal growth, metabolism and sexual maturation, however, has been given little consideration. The objectives of this work were to analyse placental biometry and structure at term, growth of foals and yearlings, their metabolism and testicular maturation at one year of age.Twenty multiparous mares (M), aged over 6 years and 12 primiparous mares (P), aged up to 5 years were artificially inseminated with the same stallion and monitored the same way until foaling. At birth, foals and placentas were measured and placentas were sampled above at the umbilical cord insertion, as well as in the pregnant and the non-pregnant horn to perform stereological analyses. Foals were weighed and measured until 540 days of age. At 120 and 360 days of age, an Intravenous Glucose Tolerance Test was performed on foals and yearlings. At 360 days of age, the males were castrated and testicular maturation analysed by RT-qPCR.At birth, P dams produced lighter and smaller foals and placentas. The foal birth weight to placental surface ratio was lower in the P compared to the M group. P Foals remained lighter than M foals until 360 days of age and smaller until at least 540 days of age. At 120 days of age, P foals had a higher glucose tolerance than M foals, and then may be less mature than M foals in terms of the control of their glucose homeostasis. At 360 days of age, the testicles of prepubertal P stallions were less mature in the P vs the M group.In conclusion, primiparous dams produce intrauterine growth restricted, less mature and smaller foals compared to multiparous dams with altered metabolism and growth until at least 540 days of age. These differences could affect the sport career of these foals, especially if it begins at an early age.

Antenatal ultrasound screening using check list before delivery for predicting a non-reassuring fetal status during labor

Objective: To clarify the effectiveness of ultrasound screening at 36 weeks’ gestation for predicting a non-reassuring fetal status during labor (NRFS).Methods: A prospective cohort study was conducted between 2012 and 2013. Ultrasound evaluations of umbilical cord and placental abnormalities and fetal biometry were performed among pregnant females at 36 weeks’ gestation. Patients who underwent ultrasound screening were divided into three risk level groups according to their abnormalities. After delivery, NRFS and emergency Cesarean section (eCS) rate were compared between the risk groups.Results: A total of 790 subjects were analyzed. Elective Cesarean section was performed in 111 cases. Consequently, 34 cases in the high-risk group, 45 cases in the middle-risk group and 600 cases in the low-risk group were analyzed. NRFS was diagnosed in 17.6%* of the patients in the high-risk group, 11.1%* of the patients in the middle-risk group and 5.6% of the patient’s in the low-risk group. eCS was performed in 8.8%* of the high-risk subjects, 4.4%* of the middle-risk subjects and 0.8% of the low-risk subjects (*p < 0.05 compared to the low-risk group).Conclusions: The use of antenatal ultrasound screening and risk classification effectively identifies cases of NRFS during delivery.

Third trimester placental volume and biometry measurement: A method-development study

ObjectivesTo test the hypothesis that third trimester placental biometry and volume can be measured by two-dimensional (2D) and three-dimensional (3D) ultrasound in utero, determining which method of measurement was most strongly correlated with true placental size ex vivo. MethodsSingleton pregnancies underwent placental ultrasound within seven days of delivery (n = 87, 29+3–41+5 weeks). Length and width (linear and curvilinear) and depth were estimated. Placental volume (PV) was estimated using 2D ellipse and shell techniques and 3D rotational (15⁰ and 30⁰ rotation angles) and multiplanar (5 and 10 mm slicing intervals) techniques. Measurements were compared to their true correlates following delivery. Intra- and inter-observer reliabilities of candidate placental size estimates were assessed by intraclass correlation coefficient (ICC). ResultsCurvilinear placental length (Rs = 0.24, p = 0.031), width (Rs = 0.27, p = 0.013) and depth (Rs = 0.31, p = 0.0056) correlated well with ex vivo measurements. All methods of PV estimation were related to ex vivo volume (Rs ≥ 0.32, p < 0.01) but not placental weight (p > 0.05); 30° rotational estimation demonstrated the strongest biological correlation (Rs = 0.40, p = 0.0004). Intra- and inter-observer placental size measurements intraclass correlation coefficients were suboptimal (0.59–0.70 and 0.10–0.58 respectively). DiscussionWe have demonstrated that it is possible to obtain information about the size of the third trimester placenta in utero using 2D and 3D ultrasound. However it is essential that the reliability (particularly interobserver reliability) of these estimates is improved prior to prospective studies to determine their predictive value.

Sex specific adaptations in placental biometry of overweight and obese women

IntroductionPlacental biometry at birth has been shown to predict chronic disease in later life. We hypothesized that maternal overweight/obesity, a state of low-grade inflammation and risk factor for adverse pregnancy outcome, could negatively influence placental development and that differences would be sex-specific. Methods696 women (537 normal-weight, NW; 112 overweight, OW; 47 obese, OB) with singleton uncomplicated pregnancies were prospectively enrolled at term delivery. Gestational age, maternal (age, height, pre-pregnancy BMI, gestational weight gain -GWG, hemoglobin, hematocrit and glycemia), fetal (weight, length, ponderal index, cranial circumference) and placental (weight, diameters) data were collected. Placental area, thickness and efficiency (fetal/placental weight ratio, F/P) were calculated. ResultsGWG was within standard recommendations in OB, while OW exceeded it. Placental weight was significantly higher in OW versus NW, but not in OB, leading to significantly higher placental thickness and lower F/P in this group.In the total population, a significant interaction effect between maternal BMI and fetal sex on placental weight and efficiency was found. Indeed, differences in placental parameters were present only in female offspring. DiscussionIn our population of OW and OB uncomplicated pregnancies only OW women, presenting GWG over standard recommendations, had thicker and less efficient placentas. We also reported different placental adaptation depending on fetal sex, with significant changes only in female fetuses. This may be part of a female-specific strategy aiming to ensure survival if another adverse event occurs. Customized counseling according to maternal BMI and fetal sex should be evaluated in clinical care.

Fetoplacental biometry and umbilical artery Doppler velocimetry in the overnourished adolescent model of fetal growth restriction

The purpose of this study was to evaluate ultrasonographically fetal growth trajectories, placental biometry, and umbilical artery (UA) Doppler indices in growth-restricted pregnancies of overnourished adolescent ewes and normally developing pregnancies of control-fed ewes. Singleton pregnancies were established using embryo transfer in 42 adolescent ewes that were overnourished (n = 27) or control-fed (n = 15) and were scanned at weekly intervals from 83-126 days' gestation and necropsied at 131 days' gestation (term = 145 days). Ultrasonographic placental measurements were reduced and UA Doppler indices were increased from 83 days' gestation; measurements of fetal abdominal circumference and femur length, renal volume and tibia length, and biparietal diameter were reduced from 98, 105, and 112 days' gestation, respectively, in overnourished vs control-intake pregnancies. Overnourishment of adolescent sheep dams produced late-onset asymmetric fetal growth restriction that was commensurate with brain sparing. Ultrasonographic placental biometry was already reduced and UA Doppler indices increased by mid gestation in overnourished pregnancies, preceding reduced fetal growth velocity and indicating an early nutritionally mediated insult on placental development.

Ultrasound assessment of placental function: the effectiveness of placental biometry in a low‐risk population as a predictor of a small for gestational age neonate

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. 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. 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). 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.