Gestational sac fluid volume measurements in virtual reality

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.

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.

First trimester trophoblast and placental bed vascular volume measurements in IVF or IVF/ICSI pregnancies

STUDY QUESTION

Are first trimester trophoblast volume (TV) and placental bed vascular volume (PBVV) different in IVF or IVF/ICSI pregnancies in comparison with spontaneously conceived pregnancies?

SUMMARY ANSWER

Any possible abnormal placentation in IVF or IVF/ICSI pregnancies in comparison with spontaneously conceived pregnancies is not detected by a difference in PBVV or TV at an early gestational age (GA).

WHAT IS KNOWN ALREADY

Assisted reproductive technology pregnancies have been associated with an increased risk of placenta-related adverse pregnancy outcomes. It is unclear whether these effects originate from infertility or from the technique itself.

STUDY DESIGN, SIZE, DURATION

We performed a retrospective cohort study in which 154 pregnant patients qualified for participation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Out of 154 pregnant patients, 84 conceived spontaneously and 70 conceived after IVF or IVF/ICSI. We determined the TV at 10 weeks GA by Virtual Organ Computer-aided AnaLysis measuring application and the PBVV at 12 weeks GA by the virtual reality operating system of BARCO I-Space in both subgroups. The investigators were blinded to the mode of conception during the measurements. Analysis was limited to singleton pregnancies with only one sac ever detectable.

MAIN RESULTS AND THE ROLE OF CHANCE

There were no differences in TV (mean 42.7, SD 15.9 versus mean 41.2, SD 13.9, P = 0.70) and PBVV (mean 27.6, SD 16.9 versus mean 24.8, SD 19.9, P = 0.20) between IVF or IVF/ICSI pregnancies and spontaneously conceived pregnancies. There was a significant correlation between TV and PBVV (rs = 0.283, P = 0.004).

LIMITATIONS, REASONS FOR CAUTION

The limitations of the present study concern the small size of the study groups.

WIDER IMPLICATIONS OF THE FINDINGS

IVF or IVF/ICSI does not seem to be associated with abnormal placentation.

STUDY FUNDING/COMPETING INTERESTS

This study was financially supported by the Erasmus Trustfonds, the Meindert de Hoop foundation and the Fonds NutsOhra. No competing interests are declared.

First-Trimester Detection of Surface Abnormalities: A Comparison of 2- and 3-Dimensional Ultrasound and 3-Dimensional Virtual Reality Ultrasound

The aim was to determine the diagnostic performance of 3-dimensional virtual reality ultrasound (3D_VR_US) and conventional 2- and 3-dimensional ultrasound (2D/3D_US) for first-trimester detection of structural abnormalities. Forty-eight first trimester cases (gold standard available, 22 normal, 26 abnormal) were evaluated offline using both techniques by 5 experienced, blinded sonographers. In each case, we analyzed whether each organ category was correctly indicated as normal or abnormal and whether the specific diagnosis was correctly made. Sensitivity in terms of normal or abnormal was comparable for both techniques (P = .24). The general sensitivity for specific diagnoses was 62.6% using 3D_VR_US and 52.2% using 2D/3D_US (P = .075). The 3D_VR_US more often correctly diagnosed skeleton/limb malformations (36.7% vs 10%; P = .013). Mean evaluation time in 3D_VR_US was 4:24 minutes and in 2D/3D_US 2:53 minutes (P < .001). General diagnostic performance of 3D_VR_US and 2D/3D_US apparently is comparable. Malformations of skeleton and limbs are more often detected using 3D_VR_US. Evaluation time is longer in 3D_VR_US.

Amniotic fluid as a vital sign for fetal wellbeing

Introduction: Amniotic fluid, once thought to merely provide protection and room for necessary movement and growth for the fetus, is now understood to be a highly complex and dynamic system that is studied as a data point to interpret fetal wellbeing. Methods: Assessment of amniotic fluid volume is now routine when performing a sonographic evaluation of fetal status and is an important consideration in the assessment and management of perinatal morbidity and mortality.1,2 In this review, we will cover the dynamics that affect amniotic fluid volume, review methods for measurement and quantification of volume, review definitions for normative data as related to neonatal outcomes, and provide evidence based guidance on the workup and management options for oligoydramnios and polyhydramnios in singleton and twin pregnancies. Conclusions: When abnormalities of fluid exist, appropriate workup to uncover the underlying etiology should be initiated as adverse fetal outcomes are sometimes associated with these variations from normalcy.