First-trimester crown-rump length and embryonic volume of aneuploid fetuses measured in virtual reality

Automatic Human Embryo Volume Measurement in First Trimester Ultrasound From the Rotterdam Periconception Cohort: Quantitative and Qualitative Evaluation of Artificial Intelligence

BACKGROUND

Noninvasive volumetric measurements during the first trimester of pregnancy provide unique insight into human embryonic growth and development. However, current methods, such as semiautomatic (eg, virtual reality [VR]) or manual segmentation (eg, VOCAL) are not used in routine care due to their time-consuming nature, requirement for specialized training, and introduction of inter- and intrarater variability.

OBJECTIVE

This study aimed to address the challenges of manual and semiautomatic measurements, our objective is to develop an automatic artificial intelligence (AI) algorithm to segment the region of interest and measure embryonic volume (EV) and head volume (HV) during the first trimester of pregnancy.

METHODS

We used 3D ultrasound datasets from the Rotterdam Periconception Cohort, collected between 7 and 11 weeks of gestational age. We measured the EV in gestational weeks 7, 9 and 11, and the HV in weeks 9 and 11. To develop the AI algorithms for measuring EV and HV, we used nnU-net, a state-of-the-art segmentation algorithm that is publicly available. We tested the algorithms on 164 (EV) and 92 (HV) datasets, both acquired before 2020. The AI algorithm's generalization to data acquired in the future was evaluated by testing on 116 (EV) and 58 (HV) datasets from 2020. The performance of the model was assessed using the intraclass correlation coefficient (ICC) between the volume obtained using AI and using VR. In addition, 2 experts qualitatively rated both VR and AI segmentations for the EV and HV.

RESULTS

We found that segmentation of both the EV and HV using AI took around a minute additionally, rating took another minute, hence in total, volume measurement took 2 minutes per ultrasound dataset, while experienced raters needed 5-10 minutes using a VR tool. For both the EV and HV, we found an ICC of 0.998 on the test set acquired before 2020 and an ICC of 0.996 (EV) and 0.997 (HV) for data acquired in 2020. During qualitative rating for the EV, a comparable proportion (AI: 42%, VR: 38%) were rated as excellent; however, we found that major errors were more common with the AI algorithm, as it more frequently missed limbs. For the HV, the AI segmentations were rated as excellent in 79% of cases, compared with only 17% for VR.

CONCLUSIONS

We developed 2 fully automatic AI algorithms to accurately measure the EV and HV in the first trimester on 3D ultrasound data. In depth qualitative analysis revealed that the quality of the measurement for AI and VR were similar. Since automatic volumetric assessment now only takes a couple of minutes, the use of these measurements in pregnancy for monitoring growth and development during this crucial period, becomes feasible, which may lead to better screening, diagnostics, and treatment of developmental disorders in pregnancy.

Embryonic statistical analyses reveal 2 growth phenotypes in mouse models of Down syndrome

BACKGROUND

Down syndrome is associated with several comorbidities, including intellectual disability, growth restriction, and congenital heart defects. The prevalence of Down syndrome-associated comorbidities is highly variable, and intellectual disability, although fully penetrant, ranges from mild to severe. Understanding the basis of this interindividual variability might identify predictive biomarkers of in utero and postnatal outcomes that could be used as endpoints to test the efficacy of future therapeutic interventions.

OBJECTIVE

The main objective of this study was to examine if antenatal interindividual variability exists in mouse models of Down syndrome and whether applying statistical approaches to clinically relevant measurements (ie, the weights of the embryo, placenta, and brain) could define cutoffs that discriminate between subgroups of trisomic embryos.

STUDY DESIGN

Three commonly used mouse models of Down syndrome (Dp(16)1/Yey, Ts65Dn, and Ts1Cje) and a new model (Ts66Yah) were used in this study. Trisomic and euploid littermate embryos were used from each model with total numbers of 102 for Ts66Yah, 118 for Dp(16)1/Yey, 92 for Ts65Dn, and 126 for Ts1Cje. Placental, embryonic, and brain weights and volumes at embryonic day 18.5 were compared between genotypes in each model. K-mean clustering analysis was applied to embryonic and brain weights to identify severity classes in trisomic embryos, and brain and placental volumetric measurements were compared between genotypes and classes for each strain. In addition, Ts66Yah embryos were examined for malformations because embryonic phenotypes have never been examined in this model.

RESULTS

Reduced body and brain weights were present in Ts66Yah, Dp(16)1/Yey, and Ts65Dn embyos. Cluster analysis identified 2 severity classes in trisomic embryos-mild and severe-in all 4 models that were distinguishable using a putative embryonic weight cutoff of <0.5 standard deviation below the mean. Ts66Yah trisomic embryos develop congenital anomalies that are also found in humans with Down syndrome, including congenital heart defects and renal pelvis dilation.

CONCLUSION

Statistical approaches applied to clinically relevant measurements revealed 2 classes of phenotypic severity in trisomic mouse models of Down syndrome. Analysis of severely affected trisomic animals may facilitate the identification of biomarkers and endpoints that can be used to prenatally predict outcomes and the efficacy of treatments.

Femoral posture during embryonic and early fetal development: An analysis using landmarks on the cartilaginous skeletons of ex vivo human specimens

The pre-axial border medially moves between the fetal and early postnatal periods, and the foot sole can be placed on the ground. Nonetheless, the precise timeline when this posture is achieved remains poorly understood. The hip joint is the most freely movable joint in the lower limbs and largely determines the lower-limb posture. The present study aimed to establish a timeline of lower-limb development using a precise measurement of femoral posture. Magnetic resonance images of 157 human embryonic samples (Carnegie stages [CS] 19-23) and 18 fetal samples (crown rump length: 37.2-225 mm) from the Kyoto Collection were obtained. Three-dimensional coordinates of eight selected landmarks in the lower limbs and pelvis were used to calculate the femoral posture. Hip flexion was approximately 14° at CS19 and gradually increased to approximately 65° at CS23; the flexion angle ranged from 90° to 120° during the fetal period. Hip joint abduction was approximately 78° at CS19 and gradually decreased to approximately 27° at CS23; the average angle was approximately 13° during the fetal period. Lateral rotation was greater than 90° at CS19 and CS21 and decreased to approximately 65° at CS23; the average angle was approximately 43° during the fetal period. During the embryonic period, three posture parameters (namely, flexion, abduction, and lateral rotation of the hip) were linearly correlated with each other, suggesting that the femoral posture at each stage was three-dimensionally constant and exhibited gradual and smooth change according to growth. During the fetal period, these parameters varied among individuals, with no obvious trend. Our study has merits in that lengths and angles were measured on anatomical landmarks of the skeletal system. Our obtained data may contribute to understanding development from anatomical aspects and provide valuable insights for clinical application.

Periconceptional Maternal Protein Intake from Animal and Plant Sources and the Impact on Early and Late Prenatal Growth and Birthweight: The Rotterdam Periconceptional Cohort

Plant-based diets continue to rise in popularity, including among women of reproductive age, while consequences for pregnancy outcomes have hardly been studied. During pregnancy, maternal diet is the only source of proteins for the developing fetus. Hence, we investigated the effects of periconceptional maternal animal and plant protein intake on prenatal growth and birthweight. 501 pregnancies were included from the prospective Rotterdam Periconceptional Cohort. Embryonic growth was depicted by crown-rump length (CRL) and embryonic volume (EV) at 7, 9 and 11 weeks using 3D ultrasound scans. Estimated fetal weight (EFW) at 20 weeks and birthweight were retrieved from medical records and standardized. Multivariable mixed models were used for CRL and EV trajectories, and linear regression for EFW and birthweight. A 10 g/day higher maternal animal protein intake was positively associated with increased embryonic growth (CRL: β = 0.023 √mm, p = 0.052; EV: β = 0.015 ∛cm, p = 0.012). A positive association, albeit non-significant, was found between maternal animal protein intake and EFW, and birthweight. No clear associations emerged between maternal plant protein intake and prenatal growth and birthweight, with effect estimates close to zero. In conclusion, maternal animal protein intake during the periconception period was positively associated with early and late prenatal growth and birthweight, while no associations were found between maternal plant protein intake and prenatal growth and birthweight.

First trimester anomaly scan using virtual reality (VR FETUS study): study protocol for a randomized clinical trial

Background

In recent years it has become clear that fetal anomalies can already be detected at the end of the first trimester of pregnancy by two-dimensional (2D) ultrasound. This is why increasingly in developed countries the first trimester anomaly scan is being offered as part of standard care. We have developed a Virtual Reality (VR) approach to improve the diagnostic abilities of 2D ultrasound. Three-dimensional (3D) ultrasound datasets are used in VR assessment, enabling real depth perception and unique interaction. The aim of this study is to investigate whether first trimester 3D VR ultrasound is of additional value in terms of diagnostic accuracy for the detection of fetal anomalies. Health-related quality of life, cost-effectiveness and also the perspective of both patient and ultrasonographer on the 3D VR modality will be studied.

Methods

Women in the first trimester of a high risk pregnancy for a fetus with a congenital anomaly are eligible for inclusion. This is a randomized controlled trial with two intervention arms. The control group receives ‘care as usual’: a second trimester 2D advanced ultrasound examination. The intervention group will undergo an additional first trimester 2D and 3D VR ultrasound examination. Following each examination participants will fill in validated questionnaires evaluating their quality of life and healthcare related expenses. Participants’ and ultrasonographers’ perspectives on the 3D VR ultrasound will be surveyed. The primary outcome will be the detection of fetal anomalies. The additional first trimester 3D VR ultrasound examination will be compared to ‘care as usual’. Neonatal or histopathological examinations are considered the gold standard for the detection of congenital anomalies. To reach statistical significance and 80% power with a detection rate of 65% for second trimester ultrasound examination and 70% for the combined detection of first trimester 3D VR and second trimester ultrasound examination, a sample size of 2800 participants is needed.

Discussion

First trimester 3D VR detection of fetal anomalies may improve patients’ quality of life through reassurance or earlier identification of malformations. Results of this study will provide policymakers and healthcare professionals with the highest level of evidence for cost-effectiveness of first trimester ultrasound using a 3D VR approach.

Trial registration

Dutch Trial Registration number NTR6309, date of registration 26 January 2017.

Additional benefits of three-dimensional ultrasound for prenatal assessment of twins

Three-dimensional ultrasound (3DUS) may provide additional information for prenatal assessment of twins. It may improve the diagnostic confidence of dating, nuchal translucency (NT) and chorionicity assignment in twin pregnancies. The "virtual 3DUS placentoscopy" can guide selective fetoscopic laser photocoagulation (SFLP) to treat twin-twin transfusion syndrome (TTTS). Volumetric assessment of the dysmorphic acardiac twin with the Virtual Organ Computer-aided Analysis (VOCAL) software is more accurate than the conventional ultrasound measurement. Twin anemia polycythemia (TAP) sequence and selective intrauterine growth restriction (sIUGR) may be clinically monitored with 3DUS placental volume (PV) and power Doppler vascular indices. Congenital anomalies are more common in twins. Evaluation of fetal anomalies with 3DUS could assist perinatal management. The 3DUS power Doppler can provide a better understanding of true and false umbilical cord knots, which are commonly found in monoamniotic (MA) twins. Single demise in monochorionic (MC) twin pregnancies can cause severe neurologic morbidity in the surviving co-twin. Prenatal prediction of brain injury in the surviving co-twin with unremarkable neurosonographic examination is difficult. The 3DUS power Doppler may aid in prenatal detection of subtle abnormal cerebral perfusion. Prenatal assessment of conjoined twins with 3DUS is important if emergency postnatal surgical separation is anticipated. There is no significant additional advantage in using real-time 3DUS to guide prenatal interventions. Assessment of the cervix and pelvic floor during twin pregnancies is enhanced with 3DUS. Due to lack of high-quality studies, routine prenatal 3DUS in twin pregnancies needs to be balanced with risks of excessive ultrasound exposure.

First trimester physiological development of the fetal foot position using three-dimensional ultrasound in virtual reality

Aim

In anatomic studies of the embryo, it has been established that during the development of the lower limb, several changes in foot position can be observed defined as a temporary ‘physiological clubfoot’. The aim of this study was to develop and test a measurement tool for objective documentation of the first trimester foot position in vivo and made an attempt to create a chart for first trimester foot position.

Methods

We developed a virtual orthopedic protractor for measuring foot positioning using three‐dimensional virtual reality visualization. Three‐dimensional ultrasound volumes of 112 pregnancies of women examined during the first trimester were studied in a BARCO I‐Space. The frontal angle (plantar flexion) and the lateral angle (adduction) between the leg and foot were measured from 8 until 13 weeks gestational age.

Results

We observed that the frontal angle steadily decreases, whereas the lateral angle first increases, resulting in transient physiological clubfeet position at 10‐ to 11‐week gestation, followed by a decrease to a normal foot position.

Conclusion

A transient clubfoot position is present during the normal development of the lower limbs, and it has been measured in vivo for the first time. This study emphasizes that a diagnosis of congenital clubfoot should not be made in the first trimester of pregnancy.

Periconceptional maternal one-carbon biomarkers are associated with embryonic development according to the Carnegie stages

STUDY QUESTION

Is periconceptional maternal one-carbon (I-C) metabolism associated with embryonic morphological development in non-malformed ongoing pregnancies?

SUMMARY ANSWER

Serum vitamin B12, red blood cell (RBC) folate and plasma total homocysteine (tHcy) are associated with embryonic development according to the Carnegie stages.

WHAT IS KNOWN ALREADY

Derangements in maternal I-C metabolism affect reproductive and pregnancy outcomes, as well as future health of the offspring.

STUDY DESIGN, SIZE, DURATION

Between 2010 and 2014, women with singleton ongoing pregnancies were enrolled in a prospective periconceptional cohort study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 234 pregnancies, including 138 spontaneous or IUI pregnancies with strict pregnancy dating and 96 pregnancies derived from IVF, ICSI or cryopreserved embryo transfer (IVF/ICSI pregnancies), underwent longitudinal transvaginal three-dimensional ultrasound (3D US) scans from 6+0 up to 10+2 weeks of gestation. Carnegie stages were defined using internal and external morphologic criteria in a virtual reality system. Maternal venous blood samples were collected at enrollment for serum vitamin B12, RBC folate and plasma tHcy assessment. Associations between biomarker concentrations and longitudinal Carnegie stages were investigated using linear mixed models.

MAIN RESULTS AND THE ROLE OF CHANCE

We performed a median of three 3D US scans per pregnancy (range 1-5) resulting in 600 good quality data sets for the Carnegie stage annotation (80.5%). Vitamin B12 was positively associated with embryonic development in the total study population (β = 0.001 (95% CI: 0.000; 0.002), P < 0.05) and in the subgroup of strictly dated spontaneous pregnancies (β = 0.002 (95% CI: 0.001; 0.003), P < 0.05). Low vitamin B12 concentrations (-2SD, 73.4 pmol/l) were associated with delayed embryonic development by 1.4 days (95% CI: 1.3-1.4) compared with high concentrations (+2SD, 563.1 pmol/l). RBC folate was positively associated with Carnegie stages only in IVF/ICSI pregnancies (β = 0.001 (95% CI: 0.0005; 0.0015), P < 0.05). In this group, low RBC folate concentrations (-2SD, 875.4 nmol/l) were associated with a 1.8-day delay (95% CI: 1.7-1.8) in development compared with high concentrations (+2SD, 2119.9 nmol/l). tHcy was negatively associated with embryonic development in the total study population (β = -0.08 (95% CI: -0.14; -0.02), P < 0.01), as well as in the IVF/ICSI subgroup (β = -0.08 (95% CI: -0.15; -0.01), P < 0.05). High tHcy concentrations (+2SD, 10.4 µmol/l) were associated with a delay of 1.6 days (95% CI: 1.5-1.7) in embryonic development compared with low concentrations (-2SD, 3.0 µmol/l).

LIMITATIONS, REASONS FOR CAUTION

The study was performed in a tertiary care center, resulting in high rates of folic acid supplement use and comorbidity that may reduce the external validity of our findings.

WIDER IMPLICATIONS OF THE FINDINGS

In periconceptional care, maternal I-C biomarkers should be taken into account as predictors of embryonic morphological development. Combining embryonic size measurements with morphological assessment could better define normal embryonic development.

STUDY FUNDING/COMPETING INTEREST(S)

The work was funded by the Department of Obstetrics and Gynaecology, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands. RPMST is CSO of the startup company Slimmere Zorg and CEO of eHealth Care Solutions. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

Not applicable.

Virtual reality imaging techniques in the study of embryonic and early placental health

Embryonic and placental growth and development in the first trimester of pregnancy have impact on the health of the fetus, newborn, child and even the adult. This emphasizes the importance of this often neglected period in life. The development of three-dimensional transvaginal ultrasonography in combination with virtual reality (VR) opens the possibility of accurate and reliable visualization of embryonic and placental structures with real depth perception. These techniques enable new biometry and volumetry measurements that contribute to the knowledge of the (patho)physiology of embryonic and early placental health. Examples of such measurements are the length of complex structures like the umbilical cord, vitelline duct, limbs and cerebellum or the volume of the whole embryo and brain cavities. Moreover, for the first time, embryos can now be staged in vivo (Carnegie stages) and vasculature volumes of both the embryo and the early placenta can be measured when VR is combined with power Doppler signals. These innovative developments have already been used to study associations between periconceptional maternal factors, such as age, smoking, alcohol use, diet and vitamin status, and embryonic and early placental growth and development. Future studies will also focus on the identification of abnormal embryonic and early placental development already in the earliest weeks of pregnancy, which provides opportunities for early prevention of pregnancy complications.

Periconceptional maternal 'high fish and olive oil, low meat' dietary pattern is associated with increased embryonic growth: The Rotterdam Periconceptional Cohort (Predict) Study

OBJECTIVE

To investigate the association between periconceptional maternal dietary pattern and first-trimester embryonic growth.

METHODS

This was a prospective cohort study of 228 women with a singleton ongoing pregnancy, of which 135 were strictly dated spontaneous pregnancies and 93 were pregnancies achieved after in-vitro fertilization or intracytoplasmatic sperm injection (IVF/ICSI). All women underwent serial transvaginal three-dimensional ultrasound (3D-US) examinations from 6 + 0 to 13 + 0 weeks' gestation. Crown-rump length (CRL) and embryonic volume (EV) measurements were performed using a virtual reality system. Information on periconceptional maternal dietary intake was collected via food frequency questionnaires. Principal component analysis was performed to identify dietary patterns. Associations between dietary patterns and CRL and EV trajectories were investigated using linear mixed models adjusted for potential confounders.

RESULTS

A median of five (range, one to seven) 3D-US scans per pregnancy were performed. Of 1162 datasets, quality was sufficient to perform CRL measurements in 991 (85.3%) and EV measurements in 899 (77.4%). A dietary pattern comprising high intake of fish and olive oil and a very low intake of meat was identified as beneficial for embryonic growth. In strictly dated spontaneous pregnancies, strong adherence to the 'high fish and olive oil, low meat' dietary pattern was associated with a 1.9 mm (95% CI, 0.1-3.63 mm) increase in CRL (+14.6%) at 7 weeks and a 3.4 mm (95% CI, 0.2-7.81 mm) increase (+6.9%) at 11 weeks, whereas EV increased by 0.06 cm³ (95% CI, 0.01-0.13 cm³ ) (+20.4%) at 7 weeks and 1.43 cm³ (95% CI, 0.99-1.87 cm³ ) (+14.4%) at 11 weeks. No significant association was observed in the total study population or in the IVF/ICSI subgroup.

CONCLUSION

Periconceptional maternal adherence to a high fish and olive oil, low meat dietary pattern is positively associated with embryonic growth in spontaneously conceived pregnancies. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Embryonic health: new insights, mHealth and personalised patient care

The worldwide epidemic of non-communicable diseases (NCD), including obesity, is a burden to which poor lifestyles contribute significantly. Events in early life may enhance susceptibility to NCD, with transmission into succeeding generations. This may also explain, in part, why interventions in adulthood are less effective to reduce NCD risk. New insights reveal that the early embryo, in particular, is extremely sensitive to signals from gametes, trophoblastic tissue and periconception maternal lifestyles. Embryonic size and growth as determinants of embryonic health seem to impact future health. A relatively small embryo for gestational age is associated with pregnancy complications, as well as with the risk of early features of NCD in childhood. Although personal lifestyles are modifiable, they are extremely difficult to change. Therefore, adopting a life course approach from the periconception period onwards and integrated into patient care with short-term reproductive health benefits may have important implications for future prevention of NCD. The current reproductive population is used to Internet and social media. Therefore, they can be reached via mobile phone (mHealth) platforms that provide personalised lifestyle (pre)pregnancy programs. This will offer opportunities and possibly great benefits for the health of current and succeeding generations.

First-Trimester Crown-Rump Length and Embryonic Volume of Fetuses with Structural Congenital Abnormalities Measured in Virtual Reality: An Observational Study

Background. With the introduction of three-dimensional (3D) ultrasound it has become possible to measure volumes. The relative increase in embryonic volume (EV) is much larger than that of the crown-rump length (CRL) over the same time period. We examined whether EV is a better parameter to determine growth restriction in fetuses with structural congenital abnormalities. Study Design, Subjects, and Outcome Measures. CRL and EV were measured using a Virtual Reality (VR) system in prospectively collected 3D ultrasound volumes of 56 fetuses diagnosed with structural congenital abnormalities in the first trimester of pregnancy (gestational age 7+5 to 14+5 weeks). Measured CRL and EV were converted to z-scores and to percentages of the expected mean using previously published reference curves of euploid fetuses. The one-sample t-test was performed to test significance. Results. The EV was smaller than expected for GA in fetuses with structural congenital abnormalities (-35%  p < 0.001, z-score -1.44  p < 0.001), whereas CRL was not (-6.43%  p = 0.118, z-score -0.43  p = 0.605). Conclusions. CRL is a less reliable parameter to determine growth restriction in fetuses with structural congenital abnormalities as compared with EV. By measuring EV, growth restriction in first-trimester fetuses with structural congenital abnormalities becomes more evident and enables an earlier detection of these cases.

Growth trajectories of the human embryonic head and periconceptional maternal conditions

STUDY QUESTION

Can growth trajectories of the human embryonic head be created using 3D ultrasound (3D-US) and virtual reality (VR) technology, and be associated with second trimester fetal head size and periconceptional maternal conditions?

SUMMARY ANSWER

Serial first trimester head circumference (HC) and head volume (HV) measurements were used to create reliable growth trajectories of the embryonic head, which were significantly associated with fetal head size and periconceptional maternal smoking, age and ITALIC! in vitro fertilization (IVF)/intra-cytoplasmic sperm injection (ICSI) treatment.

WHAT IS KNOWN ALREADY

Fetal growth is influenced by periconceptional maternal conditions.

STUDY DESIGN, SIZE, DURATION

We selected 149 singleton pregnancies with a live born non-malformed fetus from the Rotterdam periconception cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Bi-parietal diameter and occipital frontal diameter to calculate HC, HV and crown-rump length (CRL) were measured weekly between 9 + 0 and 12 + 6 weeks gestational age (GA) using 3D-US and VR. Fetal HC was obtained from second trimester structural anomaly scans. Growth trajectories of the embryonic head were created with general additive models and linear mixed models were used to estimate associations with maternal periconceptional conditions as a function of GA and CRL, respectively.

MAIN RESULTS

A total of 303 3D-US images of 149 pregnancies were eligible for embryonic head measurements (intra-class correlation coefficients >0.99). Associations were found between embryonic HC and fetal HC ( ITALIC! ρ = 0.617, ITALIC! P < 0.001) and between embryonic HV and fetal HC ( ITALIC! ρ = 0.660, ITALIC! P < 0.001) in ITALIC! Z-scores. Maternal periconceptional smoking was associated with decreased, and maternal age and IVF/ICSI treatment with increased growth trajectories of the embryonic head measured by HC and HV (All ITALIC! P < 0.05).

LIMITATIONS, REASONS FOR CAUTION

The consequences of the small effect sizes for neurodevelopmental outcome need further investigation. As the study population consists largely of tertiary hospital patients, external validity should be studied in the general population.

WIDER IMPLICATIONS OF THE FINDINGS

Assessment of growth trajectories of the embryonic head may be of benefit in future early antenatal care.

STUDY FUNDING/COMPETING INTERESTS

This study was funded by the Department of Obstetrics and Gynaecology, Erasmus MC University Medical Centre and Sophia Foundation for Medical Research, Rotterdam, The Netherlands (SSWO grant number 644). No competing interests are declared.

Two-Dimensional Differential Gel Electrophoresis to Identify Protein Biomarkers in Amniotic Fluid of Edwards Syndrome (Trisomy 18) Pregnancies

BACKGROUND

Edwards syndrome (ES) is a severe chromosomal abnormality with a prevalence of about 0.8 in 10,000 infants born alive. The aims of this study were to identify candidate proteins associated with ES pregnancies from amniotic fluid supernatant (AFS) using proteomics, and to explore the role of biological networks in the pathophysiology of ES.

METHODS

AFS from six second trimester pregnancies with ES fetuses and six normal cases were included in this study. Fluorescence-based two-dimensional difference gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) were used for comparative proteomic analysis. The identified proteins were further validated by Western blotting and the role of biological networks was analyzed.

RESULTS

Twelve protein spots were differentially expressed by more than 1.5-fold in the AFS of the ES pregnancies. MALDI-TOF/MS identified one up-regulated protein: apolipoprotein A1 (ApoA1), and four under-regulated proteins: vitamin D binding protein (VDBP), alpha-1-antitrypsin (A1AT), insulin-like growth factor-binding protein 1 (IGFBP-1), and transthyretin (TTR). Western blot and densitometric analysis of ApoA1, A1AT, IGFBP-1, and TTR confirmed the alteration of these proteins in the amniotic fluid samples. Biological network analysis revealed that the proteins of the ES AFS were involved mainly in lipid and hormone metabolism, immune response, and cardiovascular disease.

CONCLUSIONS

These five proteins may be involved in the pathogenesis of ES. Further studies are needed to explore.

Design and validation of a 3D virtual reality desktop system for sonographic length and volume measurements in early pregnancy evaluation

PURPOSE

To design and validate a desktop virtual reality (VR) system, for presentation and assessment of volumetric data, based on commercially off-the-shelf hardware as an alternative to a fully immersive CAVE-like I-Space VR system.

METHODS

We designed a desktop VR system, using a three-dimensional (3D) monitor and a six degrees-of-freedom tracking system. A personal computer uses the V-Scope (Erasmus MC, Rotterdam, The Netherlands) volume-rendering application, developed for the I-Space, to create a hologram of volumetric data. Inter- and intraobserver reliability for crown-rump length and embryonic volume measurements are investigated using Bland-Altman plots and intraclass correlation coefficients. Time required for the measurements was recorded.

RESULTS

Comparing the I-Space and the desktop VR system, the mean difference for crown-rump length is -0.34% (limits of agreement -2.58-1.89, ±2.24%) and for embryonic volume -0.92% (limits of agreement -6.97-5.13, ±6.05%). Intra- and interobserver intraclass correlation coefficients of the desktop VR system were all >0.99. Measurement times were longer on the desktop VR system compared with the I-Space, but the differences were not statistically significant.

CONCLUSIONS

A user-friendly desktop VR system can be put together using commercially off-the-shelf hardware at an acceptable price. This system provides a valid and reliable method for embryonic length and volume measurements and can be used in clinical practice.