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

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 size and growth and adverse birth outcomes: the Rotterdam Periconception Cohort

STUDY QUESTION

Is early embryonic size and growth in the first trimester of pregnancy associated with adverse birth outcomes?

SUMMARY ANSWER

Larger embryonic crown-rump length (CRL) and embryonic volume (EV) are associated with lower odds of adverse birth outcomes, especially small for gestational age (SGA).

WHAT IS ALREADY KNOWN

Preterm birth, SGA, and congenital anomalies are the most prevalent adverse birth outcomes with lifelong health consequences as well as high medical and societal costs. In the late first and second trimesters of pregnancy, fetuses at risk for adverse birth outcomes can be identified using 2-dimensional ultrasonography (US).

STUDY DESIGN, SIZE, DURATION

Between 2009 and 2018, singleton pregnancies were enrolled in this ongoing prospective Rotterdam Periconception Cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

This study included 918 pregnant women from a tertiary hospital in the Netherlands. Pregnancy dating was based on either a regular menstrual cycle (for natural pregnancies) or a conception date (for ART pregnancies). CRL and EV were measured using Virtual Reality software on 3-dimensional (3D) ultrasound scans, repeatedly performed around 7, 9, and 11 weeks of gestation. The main outcome measure was adverse birth outcome, defined as the composite of SGA (birth weight <10th percentile), preterm birth (<37th week of gestation), congenital anomalies (Eurocat criteria), stillbirth (>16th week of pregnancy), or early neonatal mortality (≤7 days of life). Reference curves for CRL and EV were constructed. Cross-sectional (CRL/EV <20th percentile at 7, 9, and 11 weeks of gestation) and longitudinal (CRL/EV growth trajectories between 6th and 13th weeks) regression analyses were performed, with adjustments for the participants' educational level, smoking, parity, age, BMI, geographical background, mode of conception, and fetal sex.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the 918 pregnant women included, the median age was 32.3 years, and 404 (44%) pregnancies had been conceived via ART. In 199 (22%) pregnancies, there was an adverse birth outcome. Regression analyses showed that at 7 weeks of gestation onwards, embryos with a CRL <20th percentile had an ∼2-fold increased odds of adverse birth outcome (adjusted odds ratio (aOR) 2.03, 95% CI 1.21-3.39, P = 0.007). Similar associations were found for EV <20th percentile but were not statistically significant. These findings were mainly driven by the strong association between embryonic size and SGA (e.g. 7-week CRL: aOR 2.18 (1.16-4.09), P = 0.02; 9-week EV: aOR 2.09 (1.10-3.97, P = 0.02). Longitudinal growth trajectories of CRL, but not of EV, were associated with adverse birth outcomes. Both CRL and EV growth trajectories were associated with SGA.

LIMITATIONS, REASONS FOR CAUTION

The tertiary hospital population and the availability of sophisticated 3D-ultrasound techniques limit the generalizability of this study to general populations and settings.

WIDER IMPLICATIONS OF THE FINDINGS

Already very early in the first trimester of pregnancy, embryos with increased risks of an adverse birth outcome can be identified by using 3D-US and Virtual Reality. This expands the window of opportunity to enable the development of future interventions to potentially improve pregnancy outcomes and offspring health during their life-course.

STUDY FUNDING/COMPETING INTEREST(S)

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

TRIAL REGISTRATION NUMBER

NL4115.

Prenatal diagnosis and perinatal outcomes of twin pregnancies disharmonious for one fetus with nuchal translucency above the 95th percentile

OBJECTIVE

To assess prenatal diagnosis and pregnancy outcomes in twin pregnancies where one fetus has nuchal translucency (NT) above the 95th percentile.

METHOD

In this retrospective analysis, 130 twin pregnancies (260 fetuses) in which one twin had an NT measurement above the 95th percentile while that of the other twin was normal were analyzed. Prenatal diagnostic results such as G bands, chromosomal microarray analysis, ultrasound findings, and pregnancy outcomes were reviewed.

RESULTS

Karyotype analysis and CMA results revealed that 15 (15.6 percent, 15/96) fetuses exhibited chromosomal abnormalities and that 13 fetuses were Variant of Uncertain Significance. Chromosome abnormalities were detected at a rate of 8.9% (5/56) in the DCT group and 25.0% (10/40) in the MCT group (p = 0.033, X2 = 4.571). 2 fetuses in DCT (3.9 percent, 2/51) and 4 fetuses in MCT (13.3 percent, 4/30) (p = 0.187) revealed structural abnormalities among the cases with normal prenatal diagnosis. Fetuses in the DCT group had an overall survival rate of 75.4 percent (95/126), whereas those in the MCT group had a survival rate of 60.4 percent (81/134) (p = 0.01, X2 = 6.636). According to the findings of Logistics regression analysis, NT thickening, maternal age and method of conception were all significant risk factors for chromosome abnormalities.

CONCLUSION

In twin pregnancies with one fetus with NT above the 95th percentile, the prevalence of fetal structural abnormalities of the MCT group and the DCT group were comparable. Pregnant women's age and mode of pregnancy are risk factors for chromosomal abnormalities.

Accelerated fetal growth in early pregnancy and risk of preterm birth: a prospective cohort study

BACKGROUND

Preterm birth (occurring before 37 completed weeks of gestation) affects 15 million infants annually, 7.5% of which die due to related complications. The detection and early diagnosis are therefore paramount in order to prevent the development of prematurity and its consequences. So far, focus has been laid on the association between reduced intrauterine fetal growth during late gestation and prematurity. The aim of the current study was to investigate the association between accelerated fetal growth in early pregnancy and the risk of preterm birth.

METHODS

This prospective cohort study included 69,617 singleton pregnancies without congenital malformations and with available biometric measurements during the first and second trimester. Estimation of fetal growth was based on measurements of biparietal diameter (BPD) at first and second trimester scan. We investigated the association between accelerated fetal growth and preterm birth prior to 37 weeks of gestation. The outcome was further stratified into very preterm birth (before 32 weeks of gestation) or moderate preterm birth (between 32 and 37 weeks of gestation) and medically induced or spontaneous preterm birth and was further explored.

RESULTS

The odds of prematurity were increased among fetuses with accelerated BPD growth (> 90th centile) estimated between first and second ultrasound scan, even after adjustment for possible confounders (aOR 1.36; 95% CI 1.20-1.54). The findings remained significant what regards moderate preterm births but not very preterm births. Regarding medically induced preterm birth, the odds were found to be elevated in the group of fetuses with accelerated growth in early pregnancy (aOR 1.34; 95% CI 1.11-1.63). On the contrary, fetuses with delayed fetal growth exhibited lower odds for both overall and spontaneous preterm birth.

CONCLUSIONS

Fetuses with accelerated BPD growth in early pregnancy, detected by ultrasound examination during the second trimester, exhibited increased odds of being born preterm. The findings of the current study suggest that fetal growth in early pregnancy should be taken into account when assessing the risk for preterm birth.

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.

No independent associations between preconception paternal dietary patterns and embryonic growth; the Predict Study

BACKGROUND & AIM

Several studies show the importance of periconceptional maternal dietary patterns on human embryonic growth. Healthy paternal nutrition has been associated with better semen quality and fecundability, however, evidence on the impact on pregnancy outcome is limited. Therefore, the aim of this study was to investigate the association between preconception paternal dietary patterns and first trimester embryonic growth using the parameters longitudinal crown-rump length (CRL) and embryonic volume (EV).

METHODS

A total of 638 couples were enrolled in the Rotterdam Periconceptional Cohort and received longitudinal three dimensional transvaginal ultrasound scans from 7⁺⁰ up to 12⁺⁰ weeks of gestation. Virtual reality software was used to perform offline measurements of the embryonic CRL and EV. Food frequency questionnaires (FFQ) were used to estimate habitual food intake in couples. Principal component analysis (PCA) was performed to identify paternal and maternal dietary patterns. Linear mixed models adjusted for potential confounders were applied to analyze associations between paternal and maternal dietary patterns and embryonic growth parameters.

RESULTS

The paternal dietary patterns retrieved were identified as "Whole wheat grains and Vegetables", "Sauces and Snacks Refined Grains", "Fish and Legumes" and explained 27.5% of the total variance of the dietary intake. No significant additional effects, independent of maternal dietary patters and other maternal and paternal potential confounders, were shown of these paternal dietary patterns on embryonic growth in spontaneous or IVF/ICSI pregnancies.

CONCLUSION

No significant effects of paternal dietary patterns independent of maternal dietary patters and other parental potential confounders on embryonic growth parameters could be established in spontaneous or IVF/ICSI pregnancies. The biological importance of paternal nutrition on semen quality, however, supports the need of periconceptional tailored nutritional counselling of couples trying to conceive.

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.