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

Pearls and Pitfalls of First-Trimester US Screening and Prenatal Testing: A Pictorial Review

First-trimester US is imperative in evaluation of early pregnancy to confirm pregnancy location and number and gestational age. The 2024 Society of Radiologists in Ultrasound consensus conference established a first-trimester lexicon to highlight the importance of clear and concise language, which is incorporated and featured by the authors. With improved technologies and understanding of fetal development, first-trimester anatomic studies, between 11 weeks and 13 weeks 6 days gestation, are becoming more frequently used. While not a replacement for the second-trimester anatomic study, systematic evaluation of fetal anatomy at this early gestational age allows detection of 40%-70% of anomalies, whether structural or related to aneuploidy. All patients, regardless of age or baseline risk, should be offered screening and diagnostic testing for chromosomal abnormalities. A variety of prenatal screening approaches are available, each with strengths and limitations. Noninvasive prenatal testing with detection of fetal cell-free DNA can be performed in the first trimester and is the most sensitive and specific screening for the common fetal aneuploidies, but is not equivalent to diagnostic testing. Alternatively, serum analytes for maternal biomarkers in conjunction with nuchal translucency (NT) measurement can be used to calculate a risk estimate for common trisomies. Increased NT is the most common abnormality seen in the first trimester. Positive screening results, increased NT, or other anomaly at US should prompt genetic counseling and be confirmed with diagnostic testing (chorionic villus sampling or amniocentesis). Early detection of aneuploidy and structural anomalies allows counseling and informs decisions for pregnancy management. ©RSNA, 2025 Supplemental material is available for this article.

Fetal congenital talipes equinovarus: genomic abnormalities and obstetric follow-up results

OBJECTIVE

The etiology of congenital talipes equinovarus (CTEV) is unknown, and the relationship between chromosome microdeletion/microduplication and fetal CTEV is rarely reported. In this study, we retrospectively analyzed fetal CTEV to explore the relationship among the CTEV phenotype, chromosome microdeletion/microduplication, and obstetric outcomes.

METHODS

Chromosome karyotype analysis and single nucleotide polymorphism (SNP) array were performed for the 68 fetuses with CTEV.

RESULTS

An SNP array was performed for 68 fetuses with CTEV; pathogenic copy number variations (CNVs) were detected in eight cases (11.8%, 8/68). In addition to one case consistent with karyotype analysis, the SNP array revealed seven additional pathogenic CNVs, including three with 22q11.21 microdeletions, two with 17p12p11.2 microduplications, one with 15q11.2 microdeletions, and one with 7q11.23 microduplications. Of the seven cases carrying pathogenic CNVs, three were tested for family genetics; of these, one was de novo, and two were inherited from either the father or mother. In total, 68 fetuses with CTEV were initially identified, of which 66 cases successfully followed-up. Of these, 9 were terminated, 2 died in utero, and 55 were live births. In 9 cases, no clinical manifestations of CTEV were found at birth; the false-positive rate of prenatal ultrasound CTEVdiagnosis was thus 13.6% (9/66).

CONCLUSION

CTEV was associated with chromosome microdeletion/microduplication, the most common of which was 22q11.21 microdeletion, followed by 17p12p11.2 microduplication. Thus, further genomic detection is recommended for fetuses with CTEV showing no abnormalities on conventional karyotype analysis.

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

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

Congenital talipes equinovarus: A literature review

Congenital talipes equinovarus (CTEV) is a congenital disability characterized by leg deformities in the cavus, adducts, varus, and equinus. The etiology of CTEV is poorly understood, despite its incidence ranging from 0.76 to 3.49 cases per 1000 live births in Indonesia. CTEV involves the fixation of the foot in the adducts, varus, and equinus with concurrent soft tissue anomalies. Despite advances in treatment, disability often persists. Theoretical models have been proposed for neurological, vascular, connective tissue, bone, and muscular causes; however, the currently available data suggests that mild cases are associated with intrauterine position. CTEV's etiology appears to involve a hereditary component, as its prevalence varies by ethnic group. Genetic factors have been identified in 24-50% of cases, depending on the community studied. Based on a complex segregation analysis, the most plausible inheritance pattern is a single large-effect gene interacting with a polygenic background.

Tendon mechanical properties are enhanced via recombinant lysyl oxidase treatment

Tendon mechanical properties are significantly compromised in adult tendon injuries, tendon-related birth defects, and connective tissue disorders. Unfortunately, there currently is no effective treatment to restore native tendon mechanical properties after postnatal tendon injury or abnormal fetal development. Approaches to promote crosslinking of extracellular matrix components in tendon have been proposed to enhance insufficient mechanical properties of fibrotic tendon after healing. However, these crosslinking agents, which are not naturally present in the body, are associated with toxicity and significant reductions in metabolic activity at concentrations that enhance tendon mechanical properties. In contrast, we propose that an effective method to restore tendon mechanical properties would be to promote lysyl oxidase (LOX)-mediated collagen crosslinking in tendon during adult tissue healing or fetal tissue development. LOX is naturally occurring in the body, and we previously demonstrated LOX-mediated collagen crosslinking to be a critical regulator of tendon mechanical properties during new tissue formation. In this study, we examined the effects of recombinant LOX treatment on tendon at different stages of development. We found that recombinant LOX treatment significantly enhanced tensile and nanoscale tendon mechanical properties without affecting cell viability or collagen content, density, and maturity. Interestingly, both tendon elastic modulus and LOX-mediated collagen crosslink density plateaued at higher recombinant LOX concentrations, which may have been due to limited availability of adjacent lysine residues that are near enough to be crosslinked together. The plateau in crosslink density at higher concentrations of recombinant LOX treatments may have implications for preventing over-stiffening of tendon, though this requires further investigation. These findings demonstrate the exciting potential for a LOX-based therapeutic to enhance tendon mechanical properties via a naturally occurring crosslinking mechanism, which could have tremendous implications for an estimated 32 million acute and chronic tendon and ligament injuries each year in the U.S.

Prenatal Diagnosis of Clubfoot: Where Are We Now? Systematic Review and Meta-Analysis

The primary methods for prenatal diagnosis of Clubfoot are ultrasound (US) and magnetic resonance imaging (MRI). An ultrasound is performed between the 1st trimester and the 28th week of pregnancy and it is reported to be used as a diagnostic method alone or in combination with MRI. So far, an international consensus on the most effective screening method has not been reached. This systematic review and meta-analysis were performed to establish the most effective and reliable exam for prenatal diagnosis of Clubfoot. The literature search was conducted using a PIOS-approach from May 2021 to June 2021. Studies reporting cases of prenatal diagnosis of Clubfoot made through US and MRI conducted from January 2010 to June 2021 were included in the study and reviewed by 2 authors. The 23 selected studies included 2318 patients. A total of 11 of the studies included details on the accuracy, while the rest were used to obtain information about the primary methodology utilized. In all the selected studies, US was used as the primary diagnostic instrument. Thirteen of the studies used the US exclusively, while three used MRI in addition to US and seven performed karyotyping after US diagnosis. The US has been shown to be the instrument of choice for the prenatal diagnosis of Clubfoot. International guidelines for an ultrasonography classification of congenital clubfoot are required to reduce the inter-variability accuracy of this procedure.

The relationship between isolated pes equinovarus and aneuploidies and perinatal outcomes: Results of a tertiary center

Objective

Congenital pes equinovarus (PEV) is the most common congenital deformity of the foot, characterized by plantar flexion with a frequency of 0.2-0.3%. It can be diagnosed from the 12^th week of pregnancy. Non-isolated cases tend to be syndromic and complex. We aimed to evaluate the results of perinatally diagnosed isolated PEV.

Materials and Methods

This was a retrospective cohort study conducted between March 2015-March 2020. Women who presented for fetal anomaly screening or were referred due to any suspected fetal anomaly were subjected to detailed fetal anomaly scans and checked for the presence of PEV. Karyotype analysis was discussed for patients with PEV. Pregnancy termination was recommended for those with chromosomal/life-threatening anomalies. The diagnosis was confirmed by postnatal examination/autopsy. Postnatal diagnosis was accepted as false-positive in those with no PEV.

Results

One-hundred thirty-eight patients were found to have PEV, 41 (29.7%) of which were isolated. In the isolated group, the false-positive rate in the first trimester was significantly higher compared with the second trimester, 50%/15.3%, respectively (p<0.05). Chromosomal anomalies were detected in 2 (4.8%) patients in the isolated group. Termination was performed to 1 (2.4%) patients due to trisomy 21. In the non-isolated group, chromosomal anomalies were detected in 13 (13.4%) patients, and termination was recommended. Termination was also recommended to 18 (18.5%) patients due to anomalies incompatible with life. In the postnatal evaluation, the surgical treatment rate in the isolated/non-isolated groups was 6%/39.7% (p<0.05).

Conclusion

When PEV is diagnosed, detailed fetal anomaly screening must be performed, patients should be informed about the chromosomal anomaly risk. High false-positive rates in the first trimester should be kept in mind for diagnosis. Karyotype analysis should be recommended also to isolated cases. It should be remembered that some neuromuscular/skeletal system anomalies may occur for the first time in the postnatal period in isolated cases.

Evaluation of embryonic posture using four-dimensional ultrasound and virtual reality

Aim

To assess the possibility of embryonic posture evaluation (=feasibility, reproducibility, variation) at rest at 9 weeks' (+0–6 days) gestational age (GA) using four‐dimensional ultrasound and virtual reality (VR) techniques. Moreover, it is hypothesized that embryonic posture shows variation at the same time point in an uneventful pregnancy.

Methods

In this explorative prospective cohort study, 23 pregnant women were recruited from the Rotterdam periconceptional cohort. A transvaginal four‐dimensional ultrasound examination of 30 min per pregnancy was performed between 9 and 10 weeks' GA. The acquired datasets were offline evaluated longitudinally (i.e. per frame) using VR techniques.

Results

The ultrasound data of 16 (70%) out of 23 pregnancies were eligible for evaluation. At rest the analysis of the embryonic posture was feasible and showed a strong (>80%) intraobserver and interobserver reproducibility for most body parts. The majority of the body parts were in similar anatomic positions at rest. However, variations in anatomic positions (e.g. 6% rotated head, 9% laterally bent spine), within and between embryos, were seen at 9 weeks' GA.

Conclusion

In this unique study, we showed for the first time that embryonic posture measurements at rest can be performed in a reliable way using state‐of‐the‐art four‐dimensional ultrasound and VR techniques. Already early in prenatal life there are differences regarding posture within and between embryos.

High Frequency of Fetal Loss in Fetuses With Normal Karyotype and Nuchal Translucency ≥ 3 Among the Iranian Pregnant Women

Objective: The purpose of this study was comparison of association of three main first trimester screening factors with pregnancy outcomes among Iranian pregnant women.

Materials and methods: This prospective study was done during 2017-2019 years in Qazvin, Iran. To do so, a total of 1500pregnant women in first trimester were enrolled. At the first step, Nuchal translucency (NT) was measured in 11-13 ± 5 week, then the serum pregnancy-associated plasma protein A (PAPP-A) and free-β-human chorionic gonadotropin (free-β-HCG) were measured in 12-14 weeks of gestation. Pregnant women were followed up until the end of pregnancy for the complications of pregnancy such as intra-uterine growth retardation (IUGR), intrauterine death (IUFD), different types of fetal loss and preterm labor.

Results: The results showed that low levels of serum biomarkers had more association with pregnancy complications in comparison to high levels of them. Significant association of IUGR (P = 0.001), IUFD (P = 0.032) and pre-term labor (P = 0.002) was shown in women with low serum levels of PAPP-A in comparison to low serum levels of free-β-hCG. Significant high frequency of different types of fetal loss (IUFD, Abortion, Elective termination) was shown in fetuses with N ≥ 3 in comparison to low levels of serum biomarkers (P = 0.001).

Conclusion: This study highlighted the importance of accurately interpreting the results of the first trimester of pregnancy screening which should be considered by primatologists for subsequent pregnancy care.