Growth trajectories of the human embryonic head and periconceptional maternal conditions

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.

Chronic Inflammation Offers Hints About Viable Therapeutic Targets for Preeclampsia and Potentially Related Offspring Sequelae

The combination of hypertension with systemic inflammation during pregnancy is a hallmark of preeclampsia, but both processes also convey dynamic information about its antecedents and correlates (e.g., fetal growth restriction) and potentially related offspring sequelae. Causal inferences are further complicated by the increasingly frequent overlap of preeclampsia, fetal growth restriction, and multiple indicators of acute and chronic inflammation, with decreased gestational length and its correlates (e.g., social vulnerability). This complexity prompted our group to summarize information from mechanistic studies, integrated with key clinical evidence, to discuss the possibility that sustained or intermittent systemic inflammation-related phenomena offer hints about viable therapeutic targets, not only for the prevention of preeclampsia, but also the neurobehavioral and other developmental deficits that appear to be overrepresented in surviving offspring. Importantly, we feel that carefully designed hypothesis-driven observational studies are necessary if we are to translate the mechanistic evidence into child health benefits, namely because multiple pregnancy disorders might contribute to heightened risks of neuroinflammation, arrested brain development, or dysconnectivity in survivors who exhibit developmental problems later in life.

Maternal fatty acid intake and human embryonic growth: the Rotterdam Periconception Cohort

The required intake of macronutrients by women during the periconceptional period for optimal fetal growth is the subject of ongoing investigation. Intake of polyunsaturated fatty acids (PUFA) is positively associated with fetal neural development, growth velocity and birth weight. However, limited evidence indicates that PUFAs play a role in embryogenesis. We aim to investigate the associations between maternal PUFA dietary intake and first trimester embryonic volume (EV) and head volume (HV). In a prospective cohort study (2013-2020), 464 pregnant women at < 8 weeks of gestation were included. Maternal dietary intake of PUFAs, including omega 3 (docosahexaenoic acid, DHA and eicosapentaeonic acid, EPA) and 6, was obtained from food frequency questionnaires, and first trimester three-dimensional ultrasound examinations were performed to measure EV and HV using Virtual Reality techniques. More than 70% of the population had omega 3 intakes below recommendations. A higher intake of PUFAs was associated with a smaller embryonic HV/EV ratio after adjusting for confounders (EPA p = 0.012, DHA p = 0.015, omega 3 and 6 p < 0.001), but no associations were found with EV or HV alone. Omega 3 from fish oil supplements alone was not associated with embryonic growth. Strong adherence to a PUFA-rich dietary pattern was associated with a smaller embryonic HV/EV ratio (DHA and EPA-rich diet p = 0.054, PUFA-rich diet p = 0.002). It is important to increase awareness of the high prevalence of omega 3-deficiency among pregnant women, and the opportunity for prevention by increasing PUFA intake, thereby reducing the risks of adverse pregnancy outcomes which originate during the periconceptional period.

Computational methods for the analysis of early-pregnancy brain ultrasonography: a systematic review

BACKGROUND

Early screening of the brain is becoming routine clinical practice. Currently, this screening is performed by manual measurements and visual analysis, which is time-consuming and prone to errors. Computational methods may support this screening. Hence, the aim of this systematic review is to gain insight into future research directions needed to bring automated early-pregnancy ultrasound analysis of the human brain to clinical practice.

METHODS

We searched PubMed (Medline ALL Ovid), EMBASE, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and Google Scholar, from inception until June 2022. This study is registered in PROSPERO at CRD42020189888. Studies about computational methods for the analysis of human brain ultrasonography acquired before the 20th week of pregnancy were included. The key reported attributes were: level of automation, learning-based or not, the usage of clinical routine data depicting normal and abnormal brain development, public sharing of program source code and data, and analysis of the confounding factors.

FINDINGS

Our search identified 2575 studies, of which 55 were included. 76% used an automatic method, 62% a learning-based method, 45% used clinical routine data and in addition, for 13% the data depicted abnormal development. None of the studies shared publicly the program source code and only two studies shared the data. Finally, 35% did not analyse the influence of confounding factors.

INTERPRETATION

Our review showed an interest in automatic, learning-based methods. To bring these methods to clinical practice we recommend that studies: use routine clinical data depicting both normal and abnormal development, make their dataset and program source code publicly available, and be attentive to the influence of confounding factors. Introduction of automated computational methods for early-pregnancy brain ultrasonography will save valuable time during screening, and ultimately lead to better detection, treatment and prevention of neuro-developmental disorders.

FUNDING

The Erasmus MC Medical Research Advisor Committee (grant number: FB 379283).

First Trimester Maternal Homocysteine and Embryonic and Fetal Growth: The Rotterdam Periconception Cohort

Homocysteine is a marker for derangements in one-carbon metabolism. Elevated homocysteine may represent a causal link between poor maternal nutrition and impaired embryonic and fetal development. We sought to investigate associations between reference range maternal homocysteine and embryonic and fetal growth. We enrolled 1060 singleton pregnancies (555 natural and 505 in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) pregnancies) from November 2010 to December 2020. Embryonic and fetal body and head growth was assessed throughout pregnancy using three-dimensional ultrasound scans and virtual reality techniques. Homocysteine was negatively associated with first trimester embryonic growth in the included population (crown-rump length B −0.023 mm, 95% CI −0.038,−0.007, p = 0.004, embryonic volume B −0.011 cm3, 95% CI −0.018,−0.004, p = 0.003). After stratification for conception mode, this association remained in IVF/ICSI pregnancies with frozen embryo transfer (crown-rump length B −0.051 mm, 95% CI −0.081,−0.023, p < 0.001, embryonic volume B −0.024 cm3, 95% CI −0.039,−0.009, p = 0.001), but not in IVF/ICSI pregnancies with fresh embryo transfer and natural pregnancies. Homocysteine was not associated with longitudinal measurements of head growth in first trimester, nor with second and third trimester fetal growth. Homocysteine in the highest quartile (7.3−14.9 µmol/L) as opposed to the lowest (2.5−5.2 µmol/L) was associated with reduced birth weight in natural pregnancies only (B −51.98 g, 95% CI −88.13,−15.84, p = 0.005). In conclusion, high maternal homocysteine within the reference range is negatively associated with first trimester embryonic growth and birth weight, and the effects of homocysteine are dependent on conception mode.

Innovative approach for first‐trimester fetal organ volume measurements using a Virtual Reality system: The Generation R Next Study

Introduction

To investigate the reproducibility of first‐trimester fetal organ volume measurements using three‐dimensional (3D) ultrasound and a Virtual Reality system.

Methods

Within a population‐based prospective cohort study, 3D ultrasound datasets of 25 first‐trimester fetuses were collected by three sonographers. We used the V‐scope application to perform Virtual Reality volume assessments of the fetal heart, lungs, and kidneys. All measurements were performed by two independent researchers.

Results

Intraobserver analyses for volume measurements of the fetal heart, lungs, and kidneys showed intraclass correlation coefficients ≥0.86, mean differences ≤8.3%, and coefficients of variation ≤22.8%. Interobserver analyses showed sufficient agreement for right lung volume measurements, but consistent measurement differences between observers for left lung, heart, and kidney volume measurements (p‐values <0.05).

Conclusion

We observed sufficient intraobserver reproducibility, but overall suboptimal interobserver reproducibility for first‐trimester fetal heart, lung, and kidney volume measurements using an innovative Virtual Reality approach. In the current stage, these measurements might be promising for the use in research settings. The reproducibility of the measurements might be further improved by novel post‐processing algorithms.

First trimester fetal proportion volumetric measurements using a Virtual Reality approach

OBJECTIVE

To establish feasibility and reproducibility of fetal proportion volumetric measurements, using three-dimensional (3D) ultrasound and a Virtual Reality (VR) system.

METHODS

Within a population-based prospective birth cohort, 3D ultrasound datasets of 50 fetuses in the late first trimester were collected by three ultrasonographers in a single research center. V-scope software was used for volumetric measurements of total fetus, extremities, head-trunk, head, trunk, thorax, and abdomen. All measurements were performed independently by two researchers. Intraobserver and interobserver reproducibility were analyzed using Bland and Altman methods.

RESULTS

Intraobserver and interobserver analyses of volumetric measurements of total fetus, head-trunk, head, trunk, thorax and abdomen showed intraclass correlation coefficients above 0.979, coefficients of variation below 7.51% and mean difference below 3.44%. The interobserver limits of agreement were within the ±10% range for volumetric measurements of total fetus, head-trunk, head and trunk. The interobserver limits of agreement for extremities, thorax and abdomen were -26.09% to 4.77%, -14.14% to 10.00% and -14.47% to 8.83%, respectively.

CONCLUSION

First trimester fetal proportion volumetric measurements using 3D ultrasound and VR are feasible and reproducible, except volumetric measurements of the fetal extremities. These novel volumetric measurements may be used in future research to enable detailed studies on first trimester fetal development and growth.

IVF with or without ICSI and the impact on human embryonic brain development: the Rotterdam Periconceptional Cohort

STUDY QUESTION

Does IVF with or without ICSI (IVF/ICSI) treatment impact the development of embryonic brain structures?

SUMMARY ANSWER

Our results show associations between IVF/ICSI treatment, smoking and slightly increased sizes of early human embryonic brain structures.

WHAT IS KNOWN ALREADY

The number of IVF/ICSI procedures is increasing worldwide and is associated with higher risks of obstetric and perinatal complications in pregnancies.

STUDY DESIGN, SIZE, DURATION

One hundred seventy-five women with a singleton pregnancy were included in the Rotterdam Periconceptional Cohort (Predict study).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Self-reported questionnaires, verified by a research assistant at enrollment, provided information on periconceptional maternal characteristics and mode of conception. Three-dimensional ultrasound (3D-US) examinations were performed at 9 and 11 weeks of gestational age (GA). Diencephalon total diameter (DTD), mesencephalon total diameter (MTD) and telencephalon thickness on the left and right site (TTL/TTR) were measured offline in standardized planes using 4D View software. Linear regression models with adjustment for GA, maternal age, body mass index, moment of initiation of folic acid supplement use and smoking were used to study associations between mode of conception and embryonic brain measurements at 9 and 11 weeks of GA.

MAIN RESULTS AND ROLE OF CHANCE

A total of 276 3D-US scans of 166 participants, of which 50 conceived through IVF/ICSI, were included for embryonic brain measurements. Success rates of the DTD and MTD measurements were between 67% and 73% and of the TTL/TTR between 52% and 57%. In the fully adjusted model, we found that at 11 weeks of GA, the MTD (ß = 0.264, 95% CI = 0.101; 0.427, P < 0.01) and TTR (ß = 0.075, 95% CI = 0.001; 0.149, P < 0.05) sizes were larger in IVF/ICSI pregnancies. In addition, smoking also resulted in larger TTL measurements at 11 weeks of GA (ß = 0.095, 95% CI= 0.005; 0.186, P < 0.05).

LIMITATIONS, REASONS FOR CAUTION

The implications of these small deviations on brain functioning need further investigation.

WIDER IMPLICATIONS OF THE FINDINGS

Enlargement of attention for prenatal brain development and postnatal neurodevelopmental outcome after IVF/ICSI treatment.

STUDY FUNDING/COMPETING INTERESTS

This study was funded by the Department of Obstetrics and Gynecology, Erasmus MC, and Sophia research foundation for Medical Research, Rotterdam, the Netherlands (SSWO grant number 644). No competing interests are declared.

TRIAL REGISTRATION NUMBER

N/A

Growth trajectories of the human fetal brain in healthy and complicated pregnancies and associations with neurodevelopmental outcome in the early life course

BACKGROUND

There is a need for non-invasive prenatal markers of the brain to assess fetuses at risk for poor postnatal neurodevelopmental outcome. Periconceptional maternal conditions and pregnancy complications impact prenatal brain development.

AIMS

To investigate associations between growth trajectories of fetal brain structures and neurodevelopmental outcome in children in the early life course.

STUDY DESIGN

Periconceptional prospective observational cohort.

SUBJECTS

Singleton pregnancies were included in the Rotterdam periconception cohort. Two- and three-dimensional ultrasound scans at 22, 26 and 32 weeks gestational age were analysed.

OUTCOME MEASURES

Head circumference (HC), cerebellum, corpus callosum (CC), Sylvian fissure, insula and parieto-occipital fissure (POF) were measured. Neurodevelopment was evaluated using the Age-and-Stages-questionnaire-3 (ASQ-3) and the Child-Behaviour-Checklist (CBCL) at 2 years of age. Linear mixed models, used to estimate the prenatal brain growth trajectories, and linear regression models, used to evaluate the associations between prenatal brain structures and neurodevelopmental outcomes, were applied in the total study population, and in subgroups: fetal growth restriction (FGR), preterm birth (PTB), fetal congenital heart disease (CHD), and uncomplicated controls.

RESULTS

Consent for participation was received from parents on behalf of their child 138/203 (68%). ASQ-3 was completed in 128/203 children (63%) and CBCL in 93/203 children (46%). Significant smaller subject-specific growth trajectories (growth rate of CC, HC, left insula, left POF and right POF and the baseline size of CC, HC, left POF and right POF) were found in the FGR subgroup, compared to the other subgroups (all p-values <0.05). In the total group (n = 138), the growth rate of the left insula was associated with poorer ASQ-3 score (β = -869.51; p < 0.05). Healthy controls (n = 106) showed a comparable association (β = -1209.87; p < 0.01). FGR (n = 10) showed a larger baseline size of the right Sylvian fissure in association with poorer CBCL-score (β = 4.13; p < 0.01). In CHD (n = 12) the baseline size of the left Sylvian fissure and its growth rate were associated with respectively poorer and better CBCL-scores (β = 3.11; p < 0.01); (β = -171.99; p < 0.01). In PTB (n = 10) no associations were found.

CONCLUSIONS

This explorative study suggests associations between ultrasound measurements of fetal brain growth and neurodevelopmental outcome at 2 years of age. In future, this non-invasive technique may improve early identification of fetuses at risk for neurodevelopmental outcome and follow-up postnatal clinical care.

The impact of maternal lifestyle factors on periconception outcomes: a systematic review of observational studies

The main risk factors for important reproductive health issues such as subfertility and perinatal mortality largely originate in the periconception period. To evaluate associations between modifiable maternal lifestyle factors and periconception outcomes, a systematic search was conducted for relevant studies published from 1990 to February 2017 on Embase, Medline, Web of Science, Cochrane database, PubMed and Google Scholar. The initial search identified 6166 articles, of which 49 studies were eligible for inclusion. Fecundity (the capacity to have a live birth) showed significant inverse associations with smoking, alcohol use and poor diet. Studies regarding time to pregnancy showed a decline in fecundity ratios (the monthly conception rate among exposed relative to unexposed couples) with increasing body mass index (BMI). Furthermore, risk of first-trimester miscarriage was found to be increased in smokers, alcohol and caffeine consumers, and with increasing BMI. Vitamin supplement use showed a decrease in this risk. This review demonstrates that maternal modifiable lifestyle factors affect periconception outcomes. If couples planning a pregnancy are more aware and supported to adopt healthy lifestyles during the periconceptional 'window of opportunity', short-term reproductive health as well as health in later life and even of future generations can be further improved.

Prenatal cerebellar growth trajectories and the impact of periconceptional maternal and fetal factors

STUDY QUESTION

CAN WE assess human prenatal cerebellar growth from the first until the third trimester of pregnancy and create growth trajectories to investigate associations with periconceptional maternal and fetal characteristics?

SUMMARY ANSWER

Prenatal growth trajectories of the human cerebellum between 9 and 32 weeks gestational age (GA) were created using three-dimensional ultrasound (3D-US) and show negative associations with pre-pregnancy and early first trimester BMI calculated from self-reported and standardized measured weight and height, respectively.

WHAT IS KNOWN ALREADY

The cerebellum is essential for normal neurodevelopment and abnormal cerebellar development has been associated with neurodevelopmental impairments and psychiatric diseases. Cerebellar development is particularly susceptible to exposures during the prenatal period, including maternal folate status, smoking habit and alcohol consumption.

STUDY DESIGN, SIZE, DURATION

From 2013 until 2015, we included 182 singleton pregnancies during the first trimester as a subgroup in a prospective periconception cohort with follow-up until birth. For the statistical analyses, we selected 166 pregnancies ending in live born infants without congenital malformations.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We measured transcerebellar diameter (TCD) at 9, 11, 22, 26 and 32 weeks GA on ultrasound scans. Growth rates were calculated and growth trajectories of the cerebellum were created. Linear mixed models were used to estimate associations between cerebellar growth and maternal age, parity, mode of conception, geographic origin, pre-pregnancy and first trimester BMI, periconceptional smoking, alcohol consumption, timing of folic acid supplement initiation and fetal gender.

MAIN RESULTS AND THE ROLE OF CHANCE

In total, 166 pregnancies provided 652 (87%) ultrasound images eligible for TCD measurements. Cerebellar growth rates increased with advancing GA being 0.1691 mm/day in the first trimester, 0.2336 mm/day in the second trimester and 0.2702 mm/day in the third trimester. Pre-pregnancy BMI, calculated from self-reported body weight and height, was significantly associated with decreased cerebellar growth trajectories (β = -0.0331 mm, 95% CI = -0.0638; -0.0024, P = 0.035). A similar association was found between cerebellar growth trajectories and first trimester BMI, calculated from standardized measurements of body weight and height (β = -0.0325, 95% CI = -0.0642; -0.0008, P = 0.045, respectively).

LIMITATIONS, REASONS FOR CAUTION

As the study population largely consisted of tertiary hospital patients, external validity should be studied in the general population. Whether small differences in prenatal cerebellar growth due to a higher pre-pregnancy and first trimester BMI have consequences for neurodevelopmental outcome needs further investigation.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings further substantiate previous evidence for the detrimental impact of a higher maternal BMI on neurodevelopmental health of offspring in later life.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the Department of Obstetrics and Gynecology, Erasmus MC University Medical Centre and Sophia Children's Hospital Fund, Rotterdam, The Netherlands (SSWO grant number 644). No competing interests are declared.

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.