Accessory thoracic muscles in human fetuses.

BACKGROUND: Typically, the anterior thoracic wall musculature is composed of the pectoralis major and pectoralis minor. Embryologically, these two muscles are originated from a common pectoral muscle mass; therefore, disruption of the normal development and differentiation could give rise to an aberrant or accessory muscle. The main aim of this study is to demonstrate and classify the accessory muscles of the pectoralis region in human fetuses. MATERIAL AND METHODS: Fifty spontaneously aborted human fetuses (25 male and 25 female, 100 sides) aged 18-38 weeks of gestation at death, and fixed in 10% formalin solution were examined. Following parental approval, the fetuses were donated to the Medical University anatomy program. The pectoralis major and minor muscle's morphology, the possible occurrence of accessory muscles of pectoral region and its morphology, their origins, and insertions, as well as the morphometric details, were assessed. RESULTS: The pectoralis major and minor were bilaterally found in all fetuses (100 cases). The accessory muscles of pectoral region were found in 16 cases (16%), and four types were differentiated. The Pectoralis Quartus muscle was the most common type of accessory muscles found in this study and occurred in 8 cases. The axillary arch muscle was observed in 3 cases. The chondrocoracoideus muscle was observed in 3 cases. The sternalis muscle occurred in 2 cases, and one of them was bifurcated. CONCLUSIONS: The thoracic region is characterized by a large amount of morphological variations, which are observed not only in adult population, but also among human fetuses. The pectoralis quartus was the most frequent variation in this study. Accessory structures like sternalis muscle, chondrocoracoideus muscle, pectoralis quartus muscle, or axillary arch muscle may have clinical implications, and knowledge about them is very useful for clinicians, especially plastic surgeons, thoracic surgeons, and orthopedics.

Growth of muscles and nerves in the upper eyelid: a morphometrical and immunohistochemical study using term human fetuses.

BACKGROUND: There is no information about muscle growth in eyelids with infrequent blinking in fetuses. METHODS: To examine the muscle and nerve morphology, we morphometrically and immunohistochemically examined sagittal sections of unilateral upper eyelids obtained from 21 term fetuses (approximately 30-42 weeks of gestation) and, for the comparison, those from 10 midterm fetuses (12-15 weeks). RESULTS: The approximation margin of the upper eyelid always corresponded to the entire free margin in midterm fetuses, whereas it was often (18/21) restricted in the posterior part in term fetuses. Thus, in the latter, the thickness at the approximation site to the lower lid often ranged from 0.8 to 1.6 mm and corresponded to 18-56% of the nearly maximum thickness of the lid. In the lower part of the upper eyelid, a layer of the orbicularis oculi muscles often (14/21) provided posterior flexion at 90-120° to extend posteriorly. Nerve fibers running along the mediolateral axis were rich along the approximation surface at term, but they might not be reported in the upper eyelid of adults. CONCLUSION: Being different from adult morphologies, the term eyelid was much thicker than the approximation surface and it carried a flexed muscle layer and transversely-running nerve. The infrequent blinking in fetuses seemed to provide a specific condition for the muscle-nerve growth. Plastic and pediatric surgeons should pay attention to a fact that infants' upper eyelid was unlikely to be a mini-version of the adult morphology.

Cochlear aqueduct revisited: A histological study using human fetuses.

BACKGROUND AND AIM: The cochlear aqueduct (CA) connects between the perilymphatic space of the cochlea and the subarachnoid space in the posterior cranial fossa. The study aimed to examine 1) whether cavitation of the CA occurs on the subarachnoid side or the cochlear side and 2) the growth and/or degeneration of the CA and its concomitant vein. METHODS: We examined paraffin-embedded histological sections from human fetuses: 15 midterm fetuses (crown-rump length or CRL, 39-115 mm) and 12 near-term fetuses (CRL, 225-328 mm). RESULTS: A linear mesenchymal condensation, i.e., a likely candidate of the CA anlage, was observed without the accompanying vein at 9-10 weeks. The vein appeared until 15 weeks, but it was sometimes distant from the CA. At 10-12 weeks, the subarachnoid space (or the epidural space) near the glossopharyngeal nerve rapidly protruded into the CA anlage and reached the scala tympani, in which cavitation was gradually on-going but without epithelial lining. However, CA cavitation did not to occur in the anlage. At the opening to the scala, the epithelial-like lining of the CA lost its meningeal structure. At near-term, the CA was often narrowed and obliterated. CONCLUSION: The CA develops from meningeal tissues when the cavitation of the scala begins. The latter cavitation seemed to reduce tissue stiffness leading, to meningeal protrusion. The so-called anlage of CA might be a phylogenetic remnant of the glossopharyngeal nerve branch. A course of cochlear veins appears to be determined by a rule different from the CA development.

Characteristic findings in the human fetus vestibule: A human temporal bone study.

OBJECTIVE: The "collapse," a highly flexed, dented, or caved membrane between the endo- and peri-lymph of the saccule and utricle in adults, is considered as a morphological aspect of Ménière's syndrome. Likewise, when mesh-like tissues in the perilymphatic space are damaged or lost, the endothelium loses mechanical support and causes nerve irritation. However, these morphologies were not examined in fetuses. METHODS: By using histological sections from 25 human fetuses (crown-rump length[CRL] 82-372 mm; approximately 12-40 weeks), morphologies of the perilymphatic-endolymphatic border membrane and the mesh-like tissue around the endothelium were examined. RESULTS: The highly flexed or caved membrane between the endo- and peri-lymphatic spaces was usually seen in the growing saccule and utricle of fetuses, especially at junctions between the utricle and ampulla at midterm. Likewise, the perilymphatic space around the saccule, utricle and semicircular ducts often lost the mesh-like tissues. The residual mesh-like tissue supported the veins, especially in the semicircular canal. CONCLUSION: Within a cartilaginous or bony room showing a limited growth in size but containing increased perilymph, the growing endothelium appeared to become wavy. Owing to a difference in growth rates between the utricle and semicircular duct, the dentation tended to be more frequently seen at junctions than at free margins of the utricle. The difference in site and gestational age suggested that the deformity was not "pathological" but occurred due to unbalanced growth of the border membrane. Nevertheless, the possibility that the deformed membrane in fetuses was an artifact caused by delayed fixation is not deniable.

Topohistology of the cranial nerves IX-XII at the cranial base and upper parapharyngeal space: A histological study using human fetuses.

The topographical relationships among the lower cranial nerves, internal carotid artery (ICA), and internal jugular vein (IJV) in the upper parapharyngeal neurovascular bundle remain obscure. Thus, details of the anatomy were examined in human fetus histology. We observed the horizontal histological sections from 20 midterm (9-18 weeks) and 12 near-term (28-40 weeks) fetuses. At the external skull base, the glossopharyngeal nerve crosses the anterior aspect of the IJV to reach the medially located Hyrtl's fissure in the petrous temporal bone. The nerve crossed the anterior aspect of the ICA medially near or below the first cervical nerve root. Below the hypoglossal nerve canal, the accessory nerve crosses the anterior or posterior aspects of the IJV and moves laterally. During the half-spiral course, the hypoglossal nerve was tightly attached to the posterolateral-anterior aspects of the vagus nerve and surrounded by a common nerve sheath. The glossopharyngeal ganglia sometimes extended inferiorly to the level of the hypoglossal nerve canal but were absent along the inferior course. The inferior vagal ganglion rarely extends above the occipital condyle. The superior cervical sympathetic ganglion occasionally extends above the first cervical nerve root. The IJV (or ICA) descends to the lateral (or medial) margins of the parapharyngeal neurovascular bundle. The glossopharyngeal (or accessory) nerve crosses the ICA (or IJV) to exit the bundle at the base of the skull (or below the hypoglossal nerve canal). The glossopharyngeal and vagus inferior ganglia differ at each site.

Changing the topographical anatomy among the maxilla, palatine bone, and greater palatine nerve: a histological study using human fetuses.

PURPOSE: The palatine bone (PAL) rides over the maxilla (MX) without an end-to-end suture in the bony palate of fetuses. However, changes in the topographical relationship among bones was unknown at and along the pterygopalatomaxillary suture, including the palatine canals. METHODS: Using sagittal, frontal, and horizontal histological sections of the head from 15 midterm fetuses to 12 near-term fetuses, we depicted the changes in the topographical anatomy of the MX, PAL, and greater palatine nerve (GPN). RESULTS: In the bony greater palatine canal of these fetuses, the medial and posterior walls facing the GPN were consistently made up of the PAL. At midterm, the entire course of the GPN was embedded in the PAL (six fetuses), or the MX contributed to the lateral wall of the nerve canal (nine). At near-term, the anterior and lateral walls showed individual variations: an MX in the anterior and lateral walls (three fetuses), an anterior MX and a lateral PAL (five), an anterior PAL and a lateral MX (two), and a PAL surrounding the GPN (four). CONCLUSION: These increasing variations suggested that the pterygopalatomaxillary suture was actually growing and that the PAL transiently expanded anteriorly and/or laterally to push the MX in fetuses. The "usual" morphology in which the GPN is sandwiched by the MX and PAL is likely established after birth, possibly during adolescence. The driving force of this change may not be produced by the masticatory apparatus. Rather, it might be triggered by the growing maxillary sinus.

Development and growth of the calcaneal tendon sheath with special reference to its topographical relationship with the tendon of the plantaris muscle: a histological study of human fetuses.

BACKGROUND AND PURPOSE: The calcaneal tendon sheath has several vascular routes and is a common site of inflammation. In adults, it is associated with the plantaris muscle tendon, but there are individual variations in the architecture and insertion site. We describe changes of the tendon sheath during fetal development. MATERIALS AND METHODS: Histological sections of the unilateral ankles of 20 fetuses were examined, ten at 8-12 weeks gestational age (GA) and twelve at 26-39 weeks GA. RESULTS: At 8-12 weeks GA, the tendon sheath simply consisted of a multilaminar layer that involved the plantaris tendon. At 26-39 weeks, each calcaneal tendon had a multilaminar sheath that could be roughly divided into three layers. The innermost layer was attached to the tendon and sometimes contained the plantaris tendon; the multilaminar intermediate layer contained vessels and often contained the plantaris tendon; and the outermost layer was thick and joined other fascial structures, such as a tibial nerve sheath and subcutaneous plantar fascia. The intermediate layer merged with the outermost layer near the insertion to the calcaneus. CONCLUSION: In spite of significant variations among adults, the fetal plantar tendon was always contained in an innermost or intermediate layer of the calcaneal tendon sheath in near-term fetuses. After birth, mechanical stresses such as walking might lead to fusion or separation of the multilaminar sheath in various manners. When reconstruction occurs postnatally, there may be individual variations in blood supply routes and morphology of the distal end of the plantaris tendon.

Cavitation processes in a space filled with loose mesenchymal tissues: a comparison between the retrosternal space and the middle ear tympanic cavity in human fetuses.

BACKGROUND: During the expansion of the pleural cavity in early fetuses, a thick sheet of loose mesenchymal tissue (SLMT) appears between the lung bud and body wall. Subsequently, the growing lung bud invades into the SLMT and the latter becomes fragmented to disappear. To compare this with the tympanic cavity filled with loose mesenchymal tissues, the present study aimed to demonstrate the development, establishment, and breaking of the SLMT in the retrosternal space. MATERIALS AND METHODS: Although the retrosternal tissue was almost absent or very thin at 7 weeks, the SLMT appeared behind the manubrium sterni at 8 weeks. Accordingly, at 9-10 weeks, cavitation occurred in the SLMT to expand the pleural cavity. Therefore, the volume of SLMT was not determined by the adjacent structures such as the pericardium and sternum. Likewise, mesenchymal tissues filling the middle ear disappeared after 26 weeks. RESULTS: There were considerable individual variations in the timing of beginning and location of the tympanic cavitation. However, in contrast to the retrosternal SLMT, the volume of the future tympanic cavity is determined by the adjacent hard tissue and tympanic membrane much earlier than the cavitation. The mesenchymal tissue carried abundant vessels in the middle ear but none or few veins in the retrosternal SLMT. CONCLUSIONS: The concept that the lung bud invades into the splanchnic mesoderm to expand the pleural cavity seems oversimplified. Mechanical stresses from the pleural cavity might induce retrosternal cavitation, while a loss in blood supply might cause tympanic cavitation.

Fetal Brain Damage in Human Fetuses with Congenital Cytomegalovirus Infection: Histological Features and Viral Tropism.

Human cytomegalovirus (HCMV) causes congenital neurological lifelong disabilities. To date, the neuropathogenesis of brain injury related to congenital HCMV (cCMV) infection is poorly understood. This study evaluates the characteristics and pathogenetic mechanisms of encephalic damage in cCMV infection. Ten HCMV-infected human fetuses at 21 weeks of gestation were examined. Specifically, tissues from different brain areas were analyzed by: (i) immunohistochemistry (IHC) to detect HCMV-infected cell distribution, (ii) hematoxylin-eosin staining to evaluate histological damage and (iii) real-time PCR to quantify tissue viral load (HCMV-DNA). The differentiation stage of HCMV-infected neural/neuronal cells was assessed by double IHC to detect simultaneously HCMV-antigens and neural/neuronal markers: nestin (a marker of neural stem/progenitor cells), doublecortin (DCX, marker of cells committed to the neuronal lineage) and neuronal nuclei (NeuN, identifying mature neurons). HCMV-positive cells and viral DNA were found in the brain of 8/10 (80%) fetuses. For these cases, brain damage was classified as mild (n = 4, 50%), moderate (n = 3, 37.5%) and severe (n = 1, 12.5%) based on presence and frequency of pathological findings (necrosis, microglial nodules, microglial activation, astrocytosis, and vascular changes). The highest median HCMV-DNA level was found in the hippocampus (212 copies/5 ng of human DNA [hDNA], range: 10-7,505) as well as the highest mean HCMV-infected cell value (2.9 cells, range: 0-23), followed by that detected in subventricular zone (1.7 cells, range: 0-19). These findings suggested a preferential viral tropism for both neural stem/progenitor cells and neuronal committed cells, residing in these regions, confirmed by the expression of DCX and nestin in 94% and 63.3% of HCMV-positive cells, respectively. NeuN was not found among HCMV-positive cells and was nearly absent in the brain with severe damage, suggesting HCMV does not infect mature neurons and immature neural/neuronal cells do not differentiate into neurons. This could lead to known structural and functional brain defects from cCMV infection.

DEVELOPMENT AND FORMATION OF THE TOPOGRAPHY OF THE INFERIOR VENA CAVA AND PULMONARY VEINS DURING THE EIGHTH MONTH OF PRENATAL HUMAN ONTOGENESIS.

OBJECTIVE: The aim: To determine the topographic features and morphometric parameters of the pulmonary veins and inferior vena cava in human fetuses during the eighth month of intrauterine development. PATIENTS AND METHODS: Materials and methods: A morphometric and histological research of 25 human fetuses in the eighth month of prenatal ontogenesis (271.0 - 310.0 mm parietal-coccygeal length) was conducted. The topographic features of the inferior vena cava and pulmonary veins during the eighth month of intrauterine development were established, and their length and diameter, as well as the change in the angle of their formation, were morphometrically determined. The formation of the topography of these veins is due to the formation of the chest and abdominal organs and continues throughout the entire fetal period of development. RESULTS: Results: The inferior vena cava is formed at the level of the body of the IV lumbar vertebra in the eighth month of the intrauterine period of human development. The initial part of the trunk of the inferior vena cava obliquely "crosses" the common iliac artery from the left to the right. At this level, the vein is located to the right and slightly behind the aorta. In fetuses of the given age group, the right adrenal gland borders the inferior vena cava only at the level of the lower 2/3 of its medial edge. At the level of the subhepatic section of the inferior vena cava, 4-5 pairs of lumbar veins flow into it. In most cases, the ductus venosus flowed into the inferior vena cava independently between the middle and left hepatic veins. Compared to other sections of the inferior vena cava, the lumen of its diaphragmatic section, which passes through the opening in the dorsal part of the tendinous center of the diaphragm on the right, increases. During this period, it was established that the pulmonary veins lie completely in the heart cavity and are surrounded by a serous membrane. In all fetuses, two pulmonary veins flow from each lung into the left atrium. The level of confluence of the venous ducts of the pulmonary veins and their number varies individually. Pulmonary veins and their ducts lie more superficially and do not repeat the passage of the corresponding bronchi and arteries, lying, as a rule, within the limits of interlobular, intersegmental, and intersubsegmental connective tissue membranes. CONCLUSION: Conclusions: In this age group, changes in venous vessels and complications in the structure of their walls and their ducts continue. The passage and branching of the bronchial tree and arterial branches (starting with the segmental branches) are almost completely identical. A significant increase in the number of small ducts was found in the system of pulmonary veins. There is an increase in the morphometric indicators of the size of the inferior vena cava in comparison with its other parts. In the wall of the pulmonary veins and inferior vena cava, all three tunics are clearly visible, which in structure are close to the definitive one.

Major change in morphology of the talofibular ligaments during fetal development and growth.

BACKGROUND AND PURPOSE: Ankle sprain is often attributed to damage of the anterior and posterior talofibular ligaments (ATFL, PTFL). We compared the morphology of these ligaments in fetuses of different gestational ages (GAs) with the horizontal configuration in adults. MATERIALS AND METHODS: Histological sections of unilateral ankles were examined in 22 fetuses, 10 at GA of 9-12 weeks and 12 at GA of 26-39 weeks. RESULTS: At a GA of 9 to 10 weeks, the ATFL and PTFL consisted of horizontally running straight fibers. The initial ATFL appeared as a thickening of the capsule of the talocrural joint, although the initial PTFL was distant from this joint. Until a GA of 12 weeks, the talus and fibula were separated by an expanding joint cavity. Thus, the initial horizontal ligaments were "pulled" in a distal direction. The distal parts of the ligaments consisted of thin collagenous fibers that had an irregular array, whereas the short proximal parts had thick fibers and a horizontal array. In near-term fetuses, the ligaments contained no horizontal fibers. The ATFL had a wavy course around the thick synovial fold, and was exposed to the joint cavity along the entire course; the distal part was thinner than the proximal part. The PTFL was bulky and consisted of fibers with an irregular array. Therefore, the morphology in a near-term fetus was quite different from that in adults. CONCLUSION: The horizontal and straight composite ankle fibers in adults apparently result from postnatal reconstruction, depending on mechanical demand.

Single-Cell Transcriptomics of Cultured Amniotic Fluid Cells Reveals Complex Gene Expression Alterations in Human Fetuses With Trisomy 18.

Trisomy 18, commonly known as Edwards syndrome, is the second most common autosomal trisomy among live born neonates. Multiple tissues including cardiac, abdominal, and nervous systems are affected by an extra chromosome 18. To delineate the complexity of anomalies of trisomy 18, we analyzed cultured amniotic fluid cells from two euploid and three trisomy 18 samples using single-cell transcriptomics. We identified 6 cell groups, which function in development of major tissues such as kidney, vasculature and smooth muscle, and display significant alterations in gene expression as detected by single-cell RNA-sequencing. Moreover, we demonstrated significant gene expression changes in previously proposed trisomy 18 critical regions, and identified three new regions such as 18p11.32, 18q11 and 18q21.32, which are likely associated with trisomy 18 phenotypes. Our results indicate complexity of trisomy 18 at the gene expression level and reveal genetic reasoning of diverse phenotypes in trisomy 18 patients.

Growth in fetuses of the constrictor pharyngis superior with special reference to its meeting with the buccinator: an embryological basis of adult variations in palatopharyngeal anatomy.

PURPOSE: The constrictor pharyngis superior (CPS) initially develops along the posterior wall of the pharyngeal mucosal tube, whereas, during the early phase, the buccinators (BC) are far anterolateral to the CPS. The process and timing of their meeting during fetal growth have not been determined. METHODS: The topographical relationship between the growing BC and CPS was assessed in histological sections from 22 early- and mid-term fetuses of approximate gestational age (GA) 8-16 weeks, and eight late-term fetuses of approximate GA 31-39 weeks. RESULTS: At 8-9 weeks, the palatopharyngeus appeared to pull the CPS up and forward. Until 11 weeks, the CPS was attached to the hamulus of the pterygoid (pterygopharyngeal part). Until 13 weeks, the CPS extended anterolaterally beyond the hamulus to meet the BC. Some BC muscle fibers originated from the oral mucosa. Notably, by 30 weeks, the CPS-BC interface had become covered by or attached to the palatopharyngeus. Muscle fibers of the palatopharyngeus, however, were thinner than those of the CPS and BC. At and near the interface, BC muscle fibers tended to run along the left-right axis, whereas those of the CPS ran anteroposteriorly. A definite fascia (i.e., a future pterygomandibular raphe) was usually absent between these muscles in fetuses. CONCLUSIONS: The excess anterior growth of the CPS with its subsequent degeneration might cause individual anatomical variations in composite muscle bundles of the palatopharyngeus-CPS complex or palatopharyngeal sphincter. A tensile transduction from the BC to the CPS through the raphe seemed unnecessary for cooperative suckling and swallowing after birth.

Vaginal development during 2nd gestational trimester: translational study in human female fetuses with disorders of the neural tube.

PURPOSE: One of the most common malformations of the central nervous system is related to embryonic neural tube alterations. We hypothesized that anencephaly affects the development of the vagina during the human second trimester of pregnancy. Our study compared the biometric parameters of the vagina in human female fetuses with neural tube defects. METHODS: In our study, 34 female fetuses were analyzed, 22 normal and 12 anencephalic, aged between 12 and 22 weeks post conception (WPC). After dissection of the pelvis and individualization of the genital tract, we evaluated the length and width of the vagina using the Image J software. We compared the means statistically using the Wilcoxon-Mann-Whitney test and performed linear regression. RESULTS: We do not identify statistical significance between the groups for the measurements of vaginal length (Control 3.12-18.33 mm/mean = 9.08 mm/SD +  - 3.77 vs. Anencephalic 2.91-13.10 mm/mean = 7.24 mm/SD +  - 2.28, p = 0.3469) and vaginal width (Control 1.04-4.86 mm/mean = 2.71 mm/SD + - 0.94 vs. Anencephalic 1.35-3.17 mm/mean = 2.13 mm/SD + - 0.65; p = 0.2503). The linear regression analysis indicated that 78.57% significance was found in the correlations in normocephalic fetuses and 57.14% significance in anencephalic fetuses (12.3-18.6 WPC). CONCLUSIONS: We do not find differences in the length and width of the vagina in anencephalic fetuses but the vaginal length and width shows a lesser tendency of growth in the anencephalic fetuses during the second trimester suggesting that anencephaly can impact the development of the vagina.

Distribution of sole Pacinian corpuscles: a histological study using near-term human feet.

INTRODUCTION: Fast-adapting afferent input from the sole Pacinian corpuscles (PCs) is essential for walking. However, the distribution of PCs in the plantar subcutaneous tissue remains unknown. MATERIALS AND METHODS: Using histological sections tangential to the plantar skin of eight near-term fetuses, we counted 528-900 PCs per sole. RESULTS: Almost half of the sole PCs existed at the level of the proximal phalanx, especially on the superficial side of the long flexor tendons and flexor digitorum brevis. Conversely, the distribution was less evident on the posterior side of the foot. The medial margin of the sole contained fewer PCs than the lateral margin, possibly due to the transverse arch. In contrast to a cluster formation in the anterior foot, posterior PCs were almost always solitary, with a distance greater than 0.5 mm to the nearest PC. DISCUSSION AND CONCLUSION: Because a receptive field of PCs is larger than that of the other receptors, fewer solitary PCs might cover the posterior sole. In infants, the amount of anterior sole PCs seemed to determine the initial walking pattern using the anterior foot without heel contact. Anterior PCs concentrated along flexor tendons might play a transient role as tendon organs during the initial learning of walking. During a lesson in infants, mechanical stress from the tendon and muscle was likely to degrade the PCs. In the near term, the sole PCs seemed not to be a mini-version of the adult morphology but suggested an infant-specific function.

Prostate and testicular growth analysis in human fetuses during the second gestational trimester.

BACKGROUND: The second gestational trimester is a very important period for male genital development. We analyzed the testicular and prostatic volume growth and compared them to the biometric parameters in human fetuses. METHODS: We studied 64 testes and 32 prostates from 32 fetuses, aged 10-22 weeks postconception. Fetuses were evaluated regarding total length, crown-rump length, and bodyweight. The same observer performed all the measurements. After testicular and prostatic dissection, the prostate and testicular length, width and thickness were recorded with the aid of computer programs (Image Pro and ImageJ software, version 1.46r). Testicular volume (TV) and prostatic volume (PV) were calculated using the ellipsoid formula. Statistical analysis was performed with the GraphPad Prism program (version 6.01). RESULTS: The fetuses presented PV between 6.1 and 297.18 mm2  (mean = 77.98 mm3 ). Linear regression analysis indicated that the PV in these fetuses increased significantly and positively with fetal age (r2 = .3120; p < .0001). We did not observe significant differences between the TV (right testis: 0.39-63.94 mm3 ; mean = 19.84 mm3 ; left testis: ​​​​​​0.52-55.37 mm3 , mean = 17.25 mm3 ). Linear regression analysis also indicated that the right and left TV (right: r2 = .6649; p < .0001 and left: r2 = .6792; p < .001) increased significantly and positively with fetal age. CONCLUSION: The prostatic growth was slower during the second gestational trimester, with significant correlations with fetal biometric parameters. The testicular growth was moderate and showed a significant correlation with fetal parameters during the studied period in human fetuses.

Urethral and bladder development during the 2nd gestational trimester applied to the urinary continence mechanism: translational study in human female fetuses with neural tube defects.

INTRODUCTION AND HYPOTHESIS: We hypothesized that anencephaly impacts female lower urinary tract development during the human fetal period. The aim of the present study is to compare the biometric parameters of the bladder and urethra in female human fetuses with and without neural tube defects. METHODS: We studied 34 female fetuses (22 normal and 12 anencephalic), aged 12 to 22 weeks post-conception (WPC). After pelvic dissection and individualization of the urinary tract structures, we evaluated the bladder and urethra length and width using Image J software. Means were statistically compared using the Wilcoxon-Mann-Whitney test, and linear regression was performed. RESULTS: We identified statistical significance between the groups regarding bladder length [normal: 6.58-19.98 mm (mean = 12.13 ± 3.21 SD) vs. anencephalic: 4.59-15.27 mm (mean = 8.79 ± 3.31 SD, p = 0.0048] and urethral length [normal: 2.22-7.04 mm (mean = 4.24 ± 1.45 SD) vs. anencephalic: 0.81-6.36 mm (mean = 3.25 ± 1.71 SD, p = 0.05]. We did not observe significant differences in bladder and urethra width between the two groups. The linear regression analysis indicated that the bladder length in anencephalic fetuses increased faster than in normal fetuses. CONCLUSIONS: We observed significant differences in the development of the bladder and urethra in fetuses with anencephaly during the fetal period studied, proving that anencephaly can affect the development of the female fetal lower urinary tract.

Bilirubin in the Vitreous Body of the Eye of Human Fetuses.

The bilirubin content in the vitreous body of the eye of human fetuses of gestation week 17-31 was measured. During gestation weeks 17-19, the mean bilirubin concentration was 8.67 µmol/liter; then, decreased to 1.37 µmol/liter (gestation weeks 20 to 31). Bilirubin, being an endogenous antioxidant, is probably involved in protection of the retina and lens from LPO processes that intensively develop in retinal neurons and lens fibers.

Are anogenital distance and external female genitalia development changed in neural tube defects? Study in human fetuses.

BACKGROUND: Anogenital distance (AGD), the distance from the anus to the genitals, is a marker of normal genital development. AGD and other biometric parameters of external female genitalia are important as ultrasonographic markers that can determine fetal gender in the first trimester. Neural tube defects are one of the commonest congenital malformations of the central nervous system, with anencephaly being the most severe defect. Female genitalia development and their association with anencephaly have not been previously described. AIM: The aim of this study was to compare the biometric parameters of external female genitalia in fetuses with anencephaly and compare it to the parameters of normocephalic fetuses at different gestational ages. STUDY DESIGN: We studied 34 female fetuses, 22 normocephalic and 12 anencephalic, aged between 12 and 22 weeks post-conception. The fetuses were placed in the classic lithotomy position and before the fetal dissection, the external female genitalia were photographed with a digital camera. Biometric parameters were recorded and measurements were performed using the Image J software, version 1.46r. Clitoral length and width, clitoris to anus distance, vaginal opening length and width, vaginal opening to labia majora distance, and AGD were measured (Figure). For statistical analysis, the Wilcoxon-Mann-Whitney test was used (p < 0.05). RESULTS: We observed a significant difference between some measurements of the groups: the vaginal opening width was significantly greater in anencephalic fetuses and the vaginal opening length, clitoris to anus distance and vaginal opening to labia majora distance were significantly greater in normocephalic fetuses. For the clitoris length and width, we did not find statistical differences. We also did not find statistical significance in AGD between groups (normocephalic 2.32 mm [2.46-6.42/SD = 2.17] vs. anencephalic 3.93 mm [1.15-6.65/SD = 1.93]; p = 0.499). The linear regression analysis indicated that AGD increased more with age in anencephalic than in the normocephalic group, but without significant differences (r2 = 0.01677; p < 0.318). DISCUSSION: This article is the first to report the female external genitalia parameters in fetuses with anencephaly. In our study we observed some alterations in biometry of the external genitalia in anencephalic fetuses, with a pattern of morphological reduction in this group. The vaginal opening length, clitoris to anus distance and vaginal opening to labia majora distance were significantly lower in anencephalic fetuses but we did not find statistical significance in clitoris measurements and AGD. CONCLUSIONS: Anencephalic fetuses had some alterations in external genitalia development, but the anogenital distances did vary significantly between the groups.

Inguinoscrotal stage of testicular descent: analysis in 217 human fetuses.

BACKGROUND: Testicular descent is a complex process of relevant importance for the comprehension of cryptorchidism. Studies about the inguinoscrotal stage of testicular migration correlating the testicular position with fetal parameters are rare in the literature. Our hypothesis is that the transition of the testis by the inguinal canal is a very fast process and occurs at the end of the third gestational trimester. AIM: To analyze the inguinoscrotal stage of testicular descent during the human fetal period. STUDY DESIGN: This is an observational study in human fetuses. We studied 217 human male fetuses ranging from 10 to 35 weeks postconception (WPC). The fetuses were well preserved and evaluated regarding crown-rump length (CRL) and body weight before dissection. Testicular position was classified as: a) abdominal, when the testis was proximal to the internal ring; b) inguinal, when it was found between the internal and external inguinal rings; and c) scrotal, when being inside the scrotum. Means were statistically compared using the unpaired t-test (P < 0.05). RESULTS: Of the 434 testes, 329 (75.8%) were abdominal, 48 (11.05%) were inguinal, and 57 (13.13%) were scrotal. The first case of inguinal testis was observed in a fetus with 17 WPC, 203 g, and 15 cm CRL. The 48 inguinal testes were observed in 29 fetuses (13.36%), aged between 17 and 29 WPC, weighing between 203 and 1220 g, and with CRL between 15 and 27.5 cm. Of the 29 fetuses with inguinal testes, 23 (79.32%) were aged between 20 and 26 WPC; 3 (10.34%) had 17 WPC; and 3 (10.34%) had more than 26 WPC. All the fetuses with more than 30 WPC had testes in the scrotum. We did not observe fetuses less than 17 WPC with the testes in the canal. DISCUSSION: We found that all fetuses with more than 30 WPC had the testes located in the scrotum and that in fetuses between 17 WPC and 25 WPC, 38 testes (8.7% of the sample) were situated in the canal and only 1 testis in a fetus with 25 WPC was located in the scrotum, showing that the second stage of testicular migration through the inguinal canal rarely occurs before the 20th WPC. CONCLUSION: The inguinoscrotal stage of testicular descent is a fast process, observed only in 13% of the fetuses and occurring with more intensity between 20 and 26 WPC.