Morphologic development of the first-trimester utero-placental vasculature is positively associated with embryonic and fetal growth: the Rotterdam Periconception Cohort

STUDY QUESTION

Is morphologic development of the first-trimester utero-placental vasculature associated with embryonic growth and development, fetal growth, and birth weight percentiles?

SUMMARY ANSWER

Using the utero-placental vascular skeleton (uPVS) as a new imaging marker, this study reveals morphologic development of the first-trimester utero-placental vasculature is positively associated with embryonic growth and development, fetal growth, and birth weight percentiles.

WHAT IS KNOWN ALREADY

First-trimester development of the utero-placental vasculature is associated with placental function, which subsequently impacts embryonic and fetal ability to reach their full growth potential. The attribution of morphologic variations in the utero-placental vascular development, including the vascular structure and branching density, on prenatal growth remains unknown.

STUDY DESIGN, SIZE, DURATION

This study was conducted in the VIRTUAL Placental study, a subcohort of 214 ongoing pregnancies, embedded in the prospective observational Rotterdam Periconception Cohort (Predict study). Women were included before 10 weeks gestational age (GA) at a tertiary referral hospital in The Netherlands between January 2017 and March 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We obtained three-dimensional power Doppler volumes of the gestational sac including the embryo and the placenta at 7, 9, and 11 weeks of gestation. Virtual Reality-based segmentation and a recently developed skeletonization algorithm were applied to the power Doppler volumes to generate the uPVS and to measure utero-placental vascular volume (uPVV). Absolute vascular morphology was quantified by assigning a morphologic characteristic to each voxel in the uPVS (i.e. end-, bifurcation-crossing-, or vessel point). Additionally, total vascular length (mm) was calculated. The ratios of the uPVS characteristics to the uPVV were calculated to determine the density of vascular branching. Embryonic growth was estimated by crown-rump length and embryonic volume. Embryonic development was estimated by Carnegie stages. Fetal growth was measured by estimated fetal weight in the second and third trimester and birth weight percentiles. Linear mixed models were used to estimate trajectories of longitudinal measurements. Linear regression analysis with adjustments for confounders was used to evaluate associations between trajectories of the uPVS and prenatal growth. Groups were stratified for conception method (natural/IVF-ICSI conceptions), fetal sex (male/female), and the occurrence of placenta-related complications (yes/no).

MAIN RESULTS AND THE ROLE OF CHANCE

Increased absolute vascular morphologic development, estimated by positive random intercepts of the uPVS characteristics, is associated with increased embryonic growth, reflected by crown-rump length (endpoints β = 0.017, 95% CI [0.009; 0.025], bifurcation points β = 0.012, 95% CI [0.006; 0.018], crossing points β = 0.017, 95% CI [0.008; 0.025], vessel points β = 0.01, 95% CI [0.002; 0.008], and total vascular length β = 0.007, 95% CI [0.003; 0.010], and similarly with embryonic volume and Carnegie stage, all P-values ≤ 0.01. Density of vascular branching was negatively associated with estimated fetal weight in the third trimester (endpoints: uPVV β = -94.972, 95% CI [-185.245; -3.698], bifurcation points: uPVV β = -192.601 95% CI [-360.532; -24.670]) and birth weight percentiles (endpoints: uPVV β = -20.727, 95% CI [-32.771; -8.683], bifurcation points: uPVV β -51.097 95% CI [-72.257; -29.937], and crossing points: uPVV β = -48.604 95% CI [-74.246; -22.961])), all P-values < 0.05. After stratification, the associations were observed in natural conceptions specifically.

LIMITATION, REASONS FOR CAUTION

Although the results of this prospective observational study clearly demonstrate associations between first-trimester utero-placental vascular morphologic development and prenatal growth, further research is required before we can draw firm conclusions about a causal relationship.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings support the hypothesis that morphologic variations in utero-placental vascular development play a role in the vascular mechanisms involved in embryonic and fetal growth and development. Application of the uPVS could benefit our understanding of the pathophysiology underlying placenta-related complications. Future research should focus on the clinical applicability of the uPVS as an imaging marker for the early detection of fetal growth restriction.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by the Department of Obstetrics and Gynecology of the Erasmus MC, University Medical Centre, Rotterdam, The Netherlands. There are no conflicts of interest.

TRIAL REGISTRATION NUMBER

Registered at the Dutch Trial Register (NTR6854).

Embryonic morphological development is delayed in pregnancies ending in a spontaneous miscarriage

STUDY QUESTION

Is there a difference in embryonic morphological development between ongoing pregnancies and live pregnancies ending in a miscarriage?

SUMMARY ANSWER

Embryonic morphological development, assessed by the Carnegie stages, is delayed in live pregnancies ending in a miscarriage compared to ongoing pregnancies.

WHAT IS KNOWN ALREADY

Pregnancies ending in a miscarriage tend to have smaller embryos and slower heart rates.

STUDY DESIGN, SIZE, DURATION

Between 2010 and 2018, 644 women with singleton pregnancies, in the periconception period, were enrolled in a prospective cohort study with follow up until 1 year after delivery. A miscarriage was registered as a non-viable pregnancy before 22 weeks gestational age, defined by an absent heartbeat by ultrasound for a previously reported live pregnancy.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Pregnant women with live singleton pregnancies were included and serial three-dimensional transvaginal ultrasound scans were performed. Embryonic morphological development was assessed by the Carnegie developmental stages and evaluated using virtual reality techniques. The embryonic morphology was compared to clinically used growth parameters (i.e. crown-rump length (CRL) and embryonic volume (EV)). Linear mixed models were used to evaluate the association between miscarriage and the Carnegie stages. Logistic regression with generalized estimating equations was used to calculate the odds of a miscarriage after a delay in Carnegie stages. Adjustments were made for potential confounders or covariates and include age, parity, and smoking status.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 611 ongoing pregnancies and 33 pregnancies ending in a miscarriage were included between 7 + 0 and 10 + 3 weeks gestational age, resulting in 1127 assigned Carnegie stages for evaluation. Compared to an ongoing pregnancy, a pregnancy ending in a miscarriage is associated with a lower Carnegie stage (βCarnegie = -0.824, 95% CI -1.190; -0.458, P < 0.001). A live embryo of a pregnancy ending in a miscarriage will reach the final Carnegie stage with a delay of 4.0 days compared to an ongoing pregnancy. A pregnancy ending in a miscarriage is associated with a smaller CRL (βCRL = -0.120, 95% CI -0.240; -0.001, P = 0.049) and EV (βEV = -0.060, 95% CI -0.112; -0.007, P = 0.027). The delay in Carnegie stage increases the odds of a miscarriage by 1.5% per delayed Carnegie stage (ORCarnegie = 1.015, 95% CI 1.002; 1.028, P = 0.028).

LIMITATIONS, REASONS FOR CAUTION

We included a relatively small number of pregnancies ending in a miscarriage from a study population that is recruited from a tertiary referral centre. Furthermore, results of genetic testing on the products of the miscarriages or information on the karyotype of the parents were not available.

WIDER IMPLICATIONS OF THE FINDINGS

Embryonic morphological development, assessed by the Carnegie stages, is delayed in live pregnancies ending in a miscarriage. In the future, embryonic morphology may be used to estimate the likelihood of a pregnancy continuing to the delivery of a healthy baby. This is of crucial importance for all women but in particular for those at risk of a recurrent pregnancy loss. As part of supportive care, both women and their partners may benefit from information on the prospective outcome of the pregnancy and the timely identification of a miscarriage.

STUDY FUNDING/COMPETING INTEREST(S)

The work was funded by the Department of Obstetrics and Gynaecology, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

P-252 Oolemma surface area impacts human pre-implantation embryo development and usage: The Rotterdam Periconception Cohort

Study question

Does oolemma area change before the 2-cell stage? Is oolemma area associated with fertilization rate, embryo usage rate and preimplantation embryo development?

Summary answer

Oolemma area is associated with preimplantation embryo development, the odds of fertilizing and developing into a used or discarded embryo.

What is known already

Current morphological grading systems are based on embryo morphology and omit oocyte morphology. Fertilization and embryo potential are largely determined by the maturation and quality of the oocyte. Oocyte quality correlates to morphology, and the very early stages of embryo development are critical to changes in oocyte size. Larger oocyte size associates with higher quality blastocyst. This suggests that oocyte size can be a morphological marker of preimplantation embryo quality and assisted reproductive treatment (ART) outcomes.

Study design, size, duration

This study is embedded in the Rotterdam Periconceptional Cohort, an ongoing prospective tertiary hospital-based birth cohort study. From May 2017 to July 2020, a subcohort of 378 women that underwent ART was included comprising of 124 pregnancies after in vitro fertilization (IVF) and 254 after intracytoplasmic sperm injection (ICSI).

Participants/materials, setting, methods

Health, lifestyle and treatment factors were collected from detailed self-reported questionnaires and medical records. Oolemma area was measured at the time of fertilization (t0), pronuclear appearance (tPNa) and fading (tPNf). Oolemma area trajectories (slope surface t0-tPNf) were calculated with linear regression. Fertilization rate, embryo usage rate, and embryo morphokinetics were analyzed in association with oolemma area and trajectories. Analyses were performed with linear mixed models, mixed effects logistic regression, and adjusted for relevant confounders.

Main results and the role of chance

Oolemma area decreased from t0 to tPNf for oocytes that developed into both used or discarded embryos. Oolemma area at t0 was strongly associated with the rate of area shrinking, as larger oolemma areas had faster shrinking rates (Bshrinking -12.55 µm²/hour, 95%CI -14.55; -10.55, p &lt; 0.001). Oocytes that resulted in a usable embryo were larger and reached tPNf faster than oocytes that resulted in a discarded embryo (tPNf 9855±595 µm2 vs 9690±721 µm2, p &lt; 0.001, 24.4±3.6 h vs 26.5±5.8 h, p &lt; 0.001). Oolemma area at tPNf did not differ between ICSI and IVF oocytes, however ICSI oocytes reached tPNf faster than IVF oocytes (23.6±3.2h and 25.9±3.8h, p &lt; 0.001, respectively). In ICSI only, larger oolemma area showed lower odds of a successful fertilization (t0 OR 0.57, 95%CI 0.48; 0.67, p &lt; 0.001), but higher odds of being cryopreserved or transferred (tPNf OR 1.66, 95%CI 1.33; 2.08, p &lt; 0.001). For IVF and ICSI, larger oolemma area at tPNF was associated with faster preimplantation development up to the morula stage (t7 B -1.41, 95%CI -2.18; -0.63, p &lt; 0.001). Oolemma area shrinking rate was not associated with embryo morphokinetics.

Limitations, reasons for caution

Small number of embryos measured at the blastocyst stage, and oolemma area measurements were not possible at t0 and tPNa for IVF oocytes.

Wider implications of the findings

Oolemma area is a suggested morphological marker for oocyte competence and an early marker for the success of fertilization and embryo development. The relevance of oolemma area as predictor of ART success requires further research. Cryopreservation and PCOS, which influence oocyte size, could be studied in association with oolemma area.

Trial registration number

not applicable

OUP accepted manuscript

STUDY QUESTION

Is periconceptional maternal smoking associated with embryonic morphological development in ongoing pregnancies?

SUMMARY ANSWER

Smoking during the periconceptional period is associated with a delayed embryonic morphological development which is not fully recuperated beyond the first trimester of pregnancy.

WHAT IS KNOWN ALREADY

Smoking during pregnancy decreases prenatal growth, increasing the risk of preterm birth, small for gestational age (GA) and childhood obesity.

STUDY DESIGN, SIZE, DURATION

Between 2010 and 2018, 689 women with ongoing singleton pregnancies were periconceptionally enrolled in a prospective cohort study with follow-up until 1 year after delivery.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Between 7 + 0 and 10 + 3 weeks, GA serial three-dimensional transvaginal ultrasound scans were performed. Embryonic morphological development as assessed by the Carnegie developmental stages was evaluated using Virtual Reality techniques. In the absence of fetal morphology classification methods beyond the embryonic period, fetal ultrasound measurements at around 20 weeks’ GA, and birth weight were used to assess fetal growth. Linear mixed models were used to evaluate the association between smoking and the Carnegie stages. Regarding first-trimester morphological development, we additionally stratified our findings for mode of conception. Multiple linear regression models were used to study the association between smoking, fetal growth and birth weight. To investigate to which extent delayed embryonic morphological development mediated the effect of smoking, contemporary mediation analysis was used. Adjustments were made for potential confounders and other covariates.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 689 singleton ongoing pregnancies were included and 1210 Carnegie stages were determined. Maternal periconceptional smoking represented by the number of cigarettes/day was associated with a slight non-significant delay of the Carnegie stages (β_{cigarettes/day} = −0.058, 95% CI −0.122; 0.007, P = 0.080). Smoking of ≥10 cigarettes/day showed the strongest association (β_{≥10 cigarettes/day} = −0.352, 95% CI −0.648; −0.057, P = 0.019), as reflected by a 0.9-day delay in reaching the final Carnegie stage. Stratification for mode of conception showed a stronger negative association between the number of cigarettes/day in the IVF/ICSI group (β_{cigarettes/day} = −0.126, 95% CI −0.200; −0.051, P = 0.001) compared to naturally conceived pregnancies (β_{cigarettes/day} = 0.009, 95% CI −0.093; 0.111, P = 0.867). In the IVF/ICSI group, periconceptional smoking of ≥10 cigarettes/day was associated with in a 1.6 day delay in reaching the final Carnegie stage (β_{≥10 cigarettes/day} = −0.510, 95% CI −0.834; −0.186, P = 0.002). In the second trimester, periconceptional smoking was associated with a smaller femur length (β_{cigarettes/day} = −0.077, 95% CI −0.147; −0.008, P = 0.029) and a larger head circumference (β_{1–9 cigarettes/day} = 0.290, 95% CI 0.065; 0.514, P = 0.012). Smoking was associated with a lower birth weight, with a dose-response effect (β_{cigarettes/day} = −0.150, 95% CI −0.233; −0.068, P < 0.001). Furthermore, using the unadjusted model, 40–60% of the association between smoking and fetal ultrasound parameters and 6.3% of the association between smoking and birth weight can be explained by a delayed embryonic morphology.

LIMITATIONS, REASONS FOR CAUTION

The study population was recruited from a tertiary referral center. Smoking habits were explored using self-reported questionnaires and checked for consistency by trained researchers.

WIDER IMPLICATIONS OF THE FINDINGS

This study shows that the association of periconceptional maternal smoking and human morphological development can already be detected early in the first trimester of pregnancy using embryonic morphology as outcome. One of the key messages of this study is that the delay, or dysregulation, in embryonic morphology is associated with allometric growth reflected by smaller fetal measurements at 20 weeks gestation and lower weight at birth. The delay in embryonic morphology, measured in early pregnancy, cannot be recuperated during the pregnancy. The results of this study emphasize the importance of smoking intervention programs prior to conception. More research is warranted to assess the association between periconceptional smoking cessation and 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. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

O-216 Culture medium used in IVF-treatment impacts post-implantation embryonic growth and developmental trajectories in a sex-specific manner

Study question

What is the (sex-specific) impact of two different culture media used in in vitro fertilization (IVF) treatment on post-implantation growth and development?

Summary answer

Embryos, especially males, cultured in SAGE 1-Step grow and morphologically develop faster in the first trimester, when compared to those cultured in Vitrolife G-1 PLUS.

What is known already

Increasing success rates after IVF can be attributed to several advancements, such as improved culture conditions. Culture media are of special interest, as they supply the embryo with essential nutrients and have previously been shown to impact birthweight. Moreover, IVF pregnancies are associated with an increased male:female ratio. However, it is unknown if culture media also have an impact prenatally. Therefore, our aim is to study the (sex-specific) impact of two different culture media (SAGE 1-Step and Vitrolife G-1 PLUS) used in IVF treatment on first-trimester embryonic growth and development, and fetal outcomes.

Study design, size, duration

Women with a viable singleton pregnancy were included before 10 weeks of gestation in the Rotterdam Periconception Cohort, an ongoing prospective tertiary hospital-based study, conducted since November 2009.

Participants/materials, setting, methods

A total of 879 pregnancies were included; 153 after culture in Vitrolife G-1 PLUS, 251 after culture in SAGE 1-Step and 475 naturally conceived. First-trimester growth and development, defined by serial crown-rump length (CRL), embryonic volume (EV) and Carnegie stages measurements were performed using state-of-the-art imaging techniques. Secondary outcomes included second trimester estimated fetal weight (EFW) and birth outcomes, and were retrieved from medical records.

Main results and the role of chance

Linear mixed model analyses, adjusted for gestational age and maternal characteristics, showed that embryos cultured in SAGE 1-Step grow faster than those cultured in Vitrolife G-1 PLUS (βEV 0.030 ∛cm3 (95%CI 0.008-0.052), p=0.007). CRL and Carnegie stages were not statistically different between culture media. After stratification for fetal sex, similar results were observed for male embryos (βEV 0.048 ∛cm3 (95%CI 0.015-0.081), p=0.005), but not for female embryos. EFW and birth outcomes were comparable between culture media in the total population and after stratification for fetal sex. Embryos cultured in SAGE 1-Step also grow faster than those conceived naturally (βEV 0.033 ∛cm3 (95%CI 0.006-0.060), p=0.018). This association was also most pronounced in male embryos (βEV 0.066 ∛cm3 (95%CI 0.024-0.108), p=0.002).

Limitations, reasons for caution

Although this study has a prospective design, its observational character does not exclude residual confounding. Furthermore, the external validity of this explorative study is limited, since participants were recruited from a tertiary university hospital.

Wider implications of the findings

Culture in SAGE 1-Step culture medium is associated with faster first-trimester growth and development, especially in male embryos. This may be the result of altered susceptibility to preimplantation environmental stressors. Further research should focus on the (sex-specific) impact of culture media on postnatal development and the susceptibility to non-communicable diseases.

Trial registration number

N/A

First-trimester utero-placental (vascular) development and embryonic and fetal growth: The Rotterdam periconception cohort

INTRODUCTION

Impaired placental development is a major cause of fetal growth restriction (FGR) and early detection will therefore improve antenatal care and birth outcomes. Here we aim to investigate serial first-trimester ultrasound markers of utero-placental (vascular) development in association with embryonic and fetal growth.

METHODS

In a prospective cohort, we periconceptionally included 214 pregnant women. Three-dimensional power Doppler ultrasonography at 7, 9 and 11 weeks gestational age (GA) was used to measure placental volumes (PV) and basal plate surface area by Virtual Organ Computer-aided AnaLysis™, and utero-placental vascular volume (uPVV), crown-rump length (CRL) and embryonic volume (EV) by a V-scope volume rendering application. Estimated fetal weight (EFW) was measured by ultrasound at 22 and 32 weeks GA and birth weight percentile (BW) was recorded. Linear mixed models and regression analyses were applied and appropriately adjusted. All analyses were stratified for fetal sex.

RESULTS

PV trajectories were positively associated with CRL (β_adj = 0.416, 95%CI:0.255; 0.576, p < 0.001), EV (β_adj = 0.220, 95%CI:0.058; 0.381, p = 0.008) and EFW (β_adj = 0.182, 95%CI:0.012; 0.352, p = 0.037). uPVV trajectories were positively associated with CRL (β_adj = 0.203, 95%CI 0.021; 0.384, p = 0.029). In girls, PV trajectories were positively associated with CRL (p < 0.001), EV (p = 0.018), EFW (p = 0.026), and uPVV trajectories were positively associated with BW (p = 0.040). In boys, positive associations were shown between PV trajectories and CRL (p = 0.002), and between uPVV trajectories and CRL (p = 0.046).

DISCUSSION

First-trimester utero-placental (vascular) development is associated with embryonic and fetal growth, with fetal sex specific modifications. This underlines the opportunity to monitor first-trimester placental development and supports the associations with embryonic and fetal growth.

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.

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.

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.

Early first-trimester trophoblast volume in pregnancies that result in live birth or miscarriage

OBJECTIVES

To assess the validity of trophoblast volume measurements on three-dimensional ultrasound (3D-US) with Virtual Organ Computer-aided AnaLysis (VOCAL(TM) ), to create reference values between 6 and 12 weeks of gestation and to compare trophoblast volume between pregnancies ending in miscarriage and those resulting in live birth.

METHODS

In a prospective periconceptional cohort, we performed weekly 3D-US in 112 singleton pregnancies resulting in a non-malformed live birth and in 56 ending in miscarriage. Scans were performed between 6 and 12 weeks. Trophoblast volumes were calculated by subtracting the gestational sac volume from the volume of the total pregnancy. The interobserver and intraobserver agreement of measurements were determined to assess validity. Reference values were created for trophoblast volume in relation to crown-rump length and gestational age.

RESULTS

A total of 722 3D-US examinations were available for offline VOCAL measurements, but measurements could be performed in only 53% of these due to non-targeted scanning and incomplete framing. Interobserver and intraobserver agreement for trophoblast volume measurements were excellent, with intraclass correlation coefficients > 0.97. Trophoblast volumes of pregnancies ending in miscarriage were significantly smaller (P < 0.01) than were those of pregnancies that resulted in live birth. Trophoblast growth in pregnancies ending in miscarriage was also reduced compared with that in pregnancies that resulted in live birth.

CONCLUSION

VOCAL is a valid technique for measuring trophoblast volume during the early first trimester of pregnancy. Pregnancies ending in miscarriage have smaller trophoblast volumes as well as reduced trophoblast growth compared with those that result in live birth.

First trimester brain ventricle fluid and embryonic volumes measured by three-dimensional ultrasound with the use of I-Space virtual reality

STUDY QUESTION

Is it possible to evaluate first trimester brain ventricle development in human pregnancies using an innovative virtual reality (VR) application and to analyze the relation of the embryonic volume (EV) and brain ventricle fluid volume (BVFV) with gestational age (GA), crown-rump length (CRL) and the Carnegie stage?

SUMMARY ANSWER

Volumetry and staging of the human embryo using a VR application make it possible to obtain unique information about in-vivo embryonic normal and abnormal development and about the sizes of the ventricles and body.

WHAT IS KNOWN ALREADY

Human brain development is complex and has a rapidly changing anatomy during the first trimester of pregnancy. New insights will enable early detection of cerebral pathology.

STUDY DESIGN, SIZE, DURATION

In a prospective cohort study, we weekly performed three-dimensional (3D) ultrasound examinations in 112 uncomplicated pregnancies between 6 + 0 and 12 + 6 weeks GA.

MATERIALS, SETTING, METHODS

The examinations resulted in 696 3D ultrasound scans that were transferred to the I-Space VR system and analyzed using V-Scope volume rendering software. V-Scope is used to create a 'hologram' of the ultrasound image and allows depth perception and interaction with the rendered objects. The CRL measurements were performed with a tracing tool, and the volume measurements were automatically performed with a segmentation algorithm. The embryos were staged according to the internal and external characteristics of the Carnegie staging system. All longitudinal outcomes were analyzed using repeated measures ANOVA.

MAIN RESULTS AND THE ROLE OF CHANCE

CRL could be measured in 91% of the datasets and ranged from 2.5 to 79.0 mm. EV could be measured in 66% of the datasets and ranged from 2.4 to 23 812.0 mm&sup3;, whereas the BVFV could be measured in 38% of the datasets and ranged from 10.4 to 226.3 mm&sup3;. Finally, in 74% of the datasets, the embryos were staged according to the Carnegie criteria, starting as early as stage 12. Reference charts of volumes versus GA, CRL and stage were constructed. There was no significant relationship between the CRL or EV and the birthweight.

LIMITATIONS, REASONS FOR CAUTIONS

The low success rate is a limitation of this study that can be explained mainly by non-targeted scanning of the embryonic head.

WIDER IMPLICATIONS OF THE FINDINGS

The I-Space VR system and the V-Scope software enable automatic EV and BVFV measurements and 3D observations of embryonic development in the first trimester. This allows in-vivo staging of human embryos based on both internal and external morphological characteristics.

STUDY FUNDING, COMPETING INTERESTS

None.

Agreement and reliability of pelvic floor measurements during contraction using three-dimensional pelvic floor ultrasound and virtual reality

OBJECTIVES

Virtual reality is a novel method of visualizing ultrasound data with the perception of depth and offers possibilities for measuring non-planar structures. The levator ani hiatus has both convex and concave aspects. The aim of this study was to compare levator ani hiatus volume measurements obtained with conventional three-dimensional (3D) ultrasound and with a virtual reality measurement technique and to establish their reliability and agreement.

METHODS

100 symptomatic patients visiting a tertiary pelvic floor clinic with a normal intact levator ani muscle diagnosed on translabial ultrasound were selected. Datasets were analyzed using a rendered volume with a slice thickness of 1.5 cm at the level of minimal hiatal dimensions during contraction. The levator area (in cm(2)) was measured and multiplied by 1.5 to get the levator ani hiatus volume in conventional 3D ultrasound (in cm(3)). Levator ani hiatus volume measurements were then measured semi-automatically in virtual reality (cm(3) ) using a segmentation algorithm. An intra- and interobserver analysis of reliability and agreement was performed in 20 randomly chosen patients.

RESULTS

The mean difference between levator ani hiatus volume measurements performed using conventional 3D ultrasound and virtual reality was 0.10 (95% CI, - 0.15 to 0.35) cm(3). The intraclass correlation coefficient (ICC) comparing conventional 3D ultrasound with virtual reality measurements was > 0.96. Intra- and interobserver ICCs for conventional 3D ultrasound measurements were > 0.94 and for virtual reality measurements were > 0.97, indicating good reliability for both.

CONCLUSION

Levator ani hiatus volume measurements performed using virtual reality were reliable and the results were similar to those obtained with conventional 3D ultrasonography.

Gestational sac fluid volume measurements in virtual reality

OBJECTIVES

To evaluate a virtual reality (VR) application for gestational sac fluid volume (GSFV) measurements in first-trimester pregnancies and to study the correlation between different embryonic growth parameters.

METHODS

This was a prospective cohort study analyzing 180 three-dimensional (3D) ultrasound scans of 42 healthy women, performed between 5 + 5 and 12 + 6 weeks' gestational age (GA). The 3D datasets were transferred to the I-Space immersive VR system. The V-Scope application was used to create a 'hologram' of the ultrasound image, allowing depth perception and interaction with the rendered objects. Volumes were measured semi-automatically using a segmentation algorithm. In addition to the GSFV, the total gestational sac volume (GSV) and its diameter (GSD) were measured. The GSV was also calculated using the ellipsoid formula. Previously obtained measurements of embryonic volume and crown-rump length (CRL) were included in the study. The outcomes were analyzed using repeated-measures analysis of variance.

RESULTS

The GSFV was measured in 78 scans, and varied from 434 to 81 491 mm(3). A positive correlation between GSFV and GA, CRL and GSD was found. Comparison of the GSD formula constructed in our study in relation to GA with a formula that is commonly used clinically showed an increasing difference with increasing GA either side of 8 + 5 weeks. The GSFV/embryonic volume ratio showed a decrease with GA. The GSV calculated using the ellipsoid formula was on average 19.8% larger compared with the GSV measured in VR.

CONCLUSION

New charts for first-trimester GSFV were constructed using VR. These growth charts could be promising tools for studying normal and abnormal embryonic development.

An innovative virtual reality technique for automated human embryonic volume measurements

BACKGROUND

The recent introduction of virtual reality (VR) enables us to use all three dimensions in a three-dimensional (3D) image. The aim of this prospective study was to evaluate an innovative VR technique for automated 3D volume measurements of the human embryo and yolk sac in first trimester pregnancies.

METHODS

We analysed 180 3D first trimester ultrasound scans of 42 pregnancies. Scans were transferred to an I-Space VR system and visualized as 3D 'holograms' with the V-Scope volume-rendering software. A semi-automatic segmentation algorithm was used to calculate the volumes. The logarithmically transformed outcomes were analysed using repeated measurements ANOVA. Interobserver and intraobserver agreement was established by calculating intraclass correlation coefficients (ICCs).

RESULTS

Eighty-eight embryonic volumes (EVs) and 118 yolk sac volumes (YSVs) were selected and measured between 5(+5) and 12(+6) weeks of gestational age (GA). EV ranged from 14 to 29 877 mm(3) and YSV ranged from 33 to 424 mm(3). ANOVA calculations showed that when the crown-rump length (CRL) doubles, the mean EV increases 6.5-fold and when the GA doubles, the mean EV increases 500-fold (P < 0.001). Furthermore, it was found that a doubling in GA results in a 3.8-fold increase of the YSV and when the CRL doubles, the YSV increases 1.5-fold (P < 0.001). Interobserver and intraobserver agreement were both excellent with ICCs of 0.99.

CONCLUSION

We measured the human EV and YSV in early pregnancy using a VR system. This innovative technique allows us to obtain unique information about the size of the embryo using all dimensions, which may be used to differentiate between normal and abnormal human development.

Reliability of three-dimensional sonographic measurements in early pregnancy using virtual reality

OBJECTIVE

To establish the reliability of three-dimensional (3D) ultrasound measurements in early pregnancy using a virtual reality system (the Barco I-Space).

METHODS

The study included 28 pregnancies with gestational ages ranging from 6 to 14 (median, 10) weeks. 3D volumes were acquired and offline measurements were made, where possible, of the yolk sac diameter, crown-rump length, biparietal diameter, head circumference and abdominal circumference, using specialized 3D imaging software (4D View). The datasets were then transferred to the Barco I-Space, a virtual reality system that allows the observer to perceive depth and interact with volume-rendered (ultrasound) data. The 3D rendered volumes were measured using a virtual pointer, controlled by a wireless joystick. For intraobserver variability, 3D and virtual reality volumes were measured twice by one operator. For interobserver variability, another operator performed the same measurements once. All measurements were repeated three times and their mean values were used for comparisons.

RESULTS

All intraclass correlation coefficients (ICCs) comparing 4D View measurements with I-Space measurements were > 0.97. Intra- and interobserver ICCs for the 4D View measurements were > 0.96 and for the I-Space ones were > 0.98, representing good agreement.

CONCLUSIONS

The application of virtual reality is a novel method of visualizing 3D ultrasound data and perception of the depth in the I-Space offers possibilities for measuring non-planar structures. We have demonstrated that early pregnancy measurements in the I-Space are reliable. New areas of embryonic and fetal biometry can now be explored using this technique, which we tentatively name 'virtual embryoscopy'.