Fetal Research Articles

Development of nerves and vessels in the penis during the human fetal period.

Although nerves and vessels of the penis play important role in erection, there are few studies on their development in human fetus. Therefore, the objective of the present study is to analyze, quantitatively, in the corpora cavernosa and corpus spongiosum, the development of the nerves and vessels in the fetal penis at different gestational ages. Fifty-six fresh, macroscopically normal human fetuses aged from 13 to 36 weeks post-conception (WPC) were used. Gestational age was determined by the foot length criterion. Penises were immediately fixed in 10% formalin, and routinely processed for paraffin embedding, after which tissue sections from the mid-shaft were obtained. We used immunohistochemical staining to analyze the nerves and vessels in the corpus cavernous and in the corpus spongiosum. These elements were identified and quantified as percentage by using the Image-J software. The quantitative analysis showed that the percentage of nerves varied from 3.03% to 20.35% in the corpora cavernosa and from 1.89% to 23.88% in the corpus spongiosum. The linear regression analysis indicated that nerves growth (incidence) in the corpora cavernosa and corpus spongiosum correlated significantly and positively with fetal age (r2=0.9421, p<0.0001) and (r2=0.9312, p<0.0001), respectively, during the whole fetal period studied. Also, the quantitative analysis showed that the percentage of vessels varies from 2.96% to 12.86% in the corpora cavernosa and from 3.62% to 14.85% in the corpus spongiosum. The linear regression analysis indicated that vessels growth (appearance) in the corpora cavernosa and corpus spongiosum correlated significantly and positively with fetal age (r2=0.8722, p<0.0001) and (r2=0.8218, p<0.0001), respectively, during the whole fetal period studied. In addition, the linear regression analysis demonstrated a more intense growth rate of nerves in the corpus spongiosum during the 2nd trimester of gestation, when compared with nerves in the corpora cavernosa. In addition, the linear regression analysis demonstrated a more intense growth rate of vessels in the corpus spongiosum when compared with the corpora cavernosa, during the whole fetal period studied. In the fetal period, the human penis undergoes major developmental changes, notably in the content and distribution of nerves and vessels. We found strong correlation between nerves and vessels growth (amount) with fetal age, both in the corpora cavernosa and corpus spongiosum. There is significant greater proportional number of nerves than vessels during the whole fetal period studied. Also, nerves and vessels grow in a more intense rate than that of the corpora cavernosa and corpus spongiosum areas.

Opponens pollicis in fetuses: classifications, measurements, and clinical implications

A fetal investigation on the anatomical properties of opponens pollicis was not encountered in the literature in terms of surgical procedures performed in the early childhood period. In this context, this study aimed to examine the origin, insertion, and morphometric characteristics of opponens pollicis in human fetuses. Fifty-two sides of 26 fetuses (mean age: 24.08±4.22 weeks, sex: 11 males and 15 females) were dissected. The origin and insertion of the opponens pollicis were noted. The area, length, and width of the opponens pollicis were measured with the surgical microscope. Furthermore, according to the literature review, the origin and insertion of opponens pollicis were classified as seven and four types, respectively. The mean width, length, and area of the opponens pollicis were found as 3.28±1.15 mm, 7.12±2.44 mm, and 20.45±16.14 mm2, respectively. In this study, opponens pollicis most commonly started from the flexor retinaculum plus the tubercle of the trapezium (22 sides) and ended on the anterolateral side of the first metacarpal bone (41 sides). Fetal information related to morphometric characteristics and variations of opponens pollicis may be important for clinicians in reconstructive interventions on the thumb muscles in the early childhood period. Our classifications performed for the first time in the literature may guide future studies, especially those focused on thumb anomalies such as polydactyly and syndactyly.

Impact of aortic and pulmonary artery wall histology on radicular dilatation during the Ross procedure

ObjectiveIn our study, we aim to explore the structural differences between the aortic root and the pulmonary artery to better understand the process of pulmonary autograft dilatation during the Ross procedure.Materials and methodsWe studied twenty human fetuses (aged 14–36 weeks of gestation) and four adults (one female and three males, aged 30–45 years, mean age = 37 ± 16 years). Samples of aortic root and pulmonary artery were obtained through dissection. Histological examinations, including hematoxylin–eosin, Masson’s trichrome, and orcein staining, as well as immunohistochemical technique with caldesmon staining, were performed. Microscopic counting was conducted to assess the number of elastic laminae and smooth muscle cells in each arterial wall. Statistical analyses were performed using R software. Means and standard deviations were used to present central tendencies and data dispersion for elastic laminae and smooth muscle.ResultsSignificant histological differences were observed between the aortic root and pulmonary artery in both adults and fetuses. In fetuses, no difference was found between the two vessels in terms of elastic laminae (p = 0.26) and smooth muscle cells (p = 0.69). However, in adults, significant differences were found for elastic laminae (p < 0.001) and smooth muscle cells (p < 0.001) between the aorta and pulmonary artery.ConclusionsThe microscopic vascular structure impacts the mechanical properties of the pulmonary autograft wall and explains its observed dilatation remote from the Ross procedure due to wall stresses related to systemic pressure.

Analysis of the skin layers and its appendages of developing human fetuses at different trimesters of pregnancy

Analysis of the skin layers and its appendages of developing human fetuses at different trimesters of pregnancy

Adipose Tissue Macrophages of the Human Fetus.

Prenatal adipose tissue development affects body composition and growth trajectory in early infancy, therefore it is a key determinant of adiposity in childhood. Childhood overweight and obesity increase the probability of being obese as an adult. After birth and in adulthood, adipose tissue macrophages (ATMs) are relevant constituents of the fat depots, and they are necessary for physiological adipose tissue development and fat metabolism. In obesity, however, ATMs may induce chronic inflammation leading to insulin resistance, pancreatic beta cell damage and self-immunity. Despite being relevant regulators of adipose tissue development and functioning, it is unknown whether ATMs are present in the fetal adipose tissue, therefore it is elusive whether they may affect the prenatal establishment of fat depots. Here we studied the distribution of ATMs in the human fetus between gestational weeks 17 and 38 and labeled ATMs in the early postnatal life. We found that CD45+/CD14+/CD68+ ATMs infiltrated the fetal adipose tissue from the 17th week of gestation and remained persistent throughout the second and third trimesters. ATMs were phagocytic in the neonate and expressed interleukin-6, along with other pro-inflammatory gene products. These findings show that ATMs colonize the adipose tissue early in gestation, raising the possibility that intrauterine ATM-adipocyte communication may exist, eventually allowing ATMs to affect prenatal adipose tissue development.

Biparietal diameter vs crown-rump length as standard parameter for late first-trimester pregnancy dating.

To compare the precision of biparietal diameter (BPD) and crown-rump length (CRL) as predictors of gestational age in the human fetus in the late first and early second trimesters, using a population-based approach. We constructed term and gestational-age prediction curves for first-trimester dating, based on 11 041 pregnancies with 12 260 measurements of CRL and/or BPD from a population-based Norwegian clinical database. We used a population-based approach with local linear quantile regression, combined with a time-to-event strategy that compensates for induced births. Term prediction precision was assessed by estimating and comparing the prediction residual curves using a time-to-event analysis. Individual differences in gestational-age predictions from CRL and BPD were assessed using measurements performed on the same fetus on the same day. A sensitivity analysis was performed to evaluate the effect of not distinguishing between non-spontaneous and spontaneous births. CRL and BPD provided almost identical term prediction precision judged from the residual distribution. In about 51% of examinations, the difference in predicted gestational age was 1 day or less; 24% of examinations had a difference of 2 days, 14% had a difference of 3 days, 7% had a difference of 4 days and only 5% of all examinations had a difference of 5 days or more. Incorrectly removing induced births from the analysis, or treating them as spontaneous, would cause a substantial systematic prediction bias of about 2 days. Based on population data, using comparisons at an individual level, our study found that BPD is as precise as CRL when used for first-trimester dating. BPD has advantages from a clinical point of view, since it is technically less challenging and less time-consuming to measure compared with CRL, and can be measured and assessed throughout the entire pregnancy. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Quantitative anatomy of the infraspinatus muscle in the human fetus.

The study presents one of the six scapulohumeral muscles, which occupies most of the osteofibrous infraspinatus compartment. Along with the supraspinatus, teres minor and subscapularis muscles, the infraspinatus muscle contributes to the rotator cuff. It protects the posterior aspect of the articular capsule of the shoulder joint, adducts and externally rotates the arm. The aim of the study was to perform the quantitative analysis of the infraspinatus muscle in human fetuses and to elaborate growth dynamics for its morphometric parameters. Using anatomical dissection, digital image analysis (NIS Elements AR3.0) and statistics (Student's t-test, regression analysis), the vertical, transverse and oblique diameters, muscle circumference and projection surface area of the infraspinatus muscle were measured in 36human fetuses of both sexes (17♂, 19♀) aged 18-30weeks. The infraspinatus muscle revealed neither sex nor laterality differences. All examined morphometric parameters of the infraspinatus muscle increased commensurately in accordance with the following linear functions: y=-4.024 + 0.903×Age ± 0.621 (R²=0.96) for transverse diameter, y=-3.089 + 1.321×Age ± 0.897 (R²=0.97) for vertical diameter, y=-1.161 + 0.632×Age ± 0.444 (R²=0.97) for oblique diameter, y=-13.575 + 3.851×Age ± 1.938 (R²=0.98) for muscle circumference and y=-293.512 + 23.228×Age ±19.650 (R²=0.95) for projection surface area.

The Effect of Aloe vera on Skin and Its Commensals: Contribution of Acemannan in Curing Acne Caused by Propionibacterium acnes

Aloe vera is one of the most significant therapeutical plant species that belongs to the family Liliaceae. Aloe vera is composed of a high amount of water, with the remainder being dry matter. The dry matter contains a lot of bioactive compounds like carbohydrates, fats, and enzymes, with various therapeutic and antimicrobial properties. It can enhance the proliferation of cells and prevent cell damage by anti-oxidative properties (stimulating the secretion of superoxide dismutase and peroxidase). Human skin is colonized by microbes like fungi (Candida albicans), bacteria (Propionibacterium acnes, Staphylococcus aureus), and mites. These commensals are responsible for skin characteristics such as acidic pH, the pungent smell of sweat, etc. Human fetuses lack skin microbiota, and their skin is colonized after birth. Commensals present on the skin have a crucial role in training the human immune system against other pathogenic microbes. Propionibacterium acnes act as an opportunistic pathogen when the balance between the commensals is disturbed. We also emphasize the recent progress in identifying the aloe metabolite biosynthesis pathways and the associated enzyme machinery. The hyperproliferation of Propionibacterium acnes causes acne, and acemannan plays a significant role in its cure. Hence, we need to consider a new treatment approach based on the root cause of this dysbiosis.

A Statement on Abortion by 170 Obstetricians/Gynecologists after the Reversal of Roe v Wade.

In a recent American Journal of Obstetrics and Gynecology, 900 professors submitted a Special Report calling for reinstating federal protection for abortion. Here, we provide an alternative consensus statement. Induced abortion is not a constitutional right. We, too, value patient autonomy, but autonomy does not allow for causing harm to another human being, in this case, the human fetus. We share concern about maternal mortality in the United States, but evidence shows that induced abortion increases, not decreases, maternal mortality. We share the authors' concern for the effect of induced abortion on minority populations and mourn the fact that the abortion rate in non-Hispanic black patients is three times that of non-Hispanic white patients and twice that of Hispanic patients. Many obstetricians/gynecologists, like ourselves, do not support abortion, and most obstetricians/gynecologists do not perform abortions. Induced abortion is not necessary to provide evidence-based care. We also have seen tragic situations and misinformation and want to work toward addressing these issues. We support the highest level of clinical practice, bodily autonomy, reproductive freedom, and evidence-based care for both our patients-the pregnant woman and the human being in utero-whom we have dedicated our lives to serving.

Digital image analysis of vertebral body L4 and its ossification center in the human fetus.

Using a Siemens-Biograph 128 mCT camera the morphometric analysis of the L4 vertebral body and its ossification center were done in 55human fetuses aged 17 to 30weeks. No sex differences were found. The mean height, transverse and sagittal diameters of L4 vertebral body followed the logarithmic functions: y = -11.797+ 5.208 × ln(age) ± 0.372, y = -23.462 + 9.428 × ln(age) ± 0.702, y = 2.770 + 13.521 × ln(age) ± 1.722, respectively. The mean cross-sectional area of L4 vertebral body followed the linear function: y = -30.683 + 1.976 × age ± 2.701. The mean volume of L4 vertebral body followed the second-degree polynomial function: y = -93.983+ 0.385 × (age)² ± 23.707. The mean transverse and sagittal diameters of the ossification center of L4 vertebral body followed the natural logarithmic function: y = -27.106 + 10.178 × ln(age) ± 0.769 and y = -13.345 + 5.458 × ln(age) ± 0.424, respectively. The mean cross-sectional area and the volume of the ossification center of L4 vertebral body followed the linear function: y = -30.683 + 1.976 × age ± 2.701 and y = -43.214 + 2.760 × age ± 4.085, respectively.

The development of the external genitals in female human embryos and foetuses. Part 1: Perineal thick skin, clitoris and labia.

Concomitant with the rupture of the cloacal membrane in the 6th week of development, the intermediate layer of the perineal-skin epithelium thickens. We investigated its distribution and the development of the corresponding subcutaneous compartments in serial sections of female human embryos and foetuses and prepared 3D reconstructions to establish topographic relations. The thick-skin area becomes restricted to the outlets of the genital and intestinal tracts. The clitoris and labia majora become identifiable at ~7 weeks. The mesenchymal mass inside the clitoris soon divides into the glans and the cavernous bodies. The clitoral hood forms between 10 and 14 weeks as a fold of tissue that extends from proximal to distal over the glans. Due to the caudal bending of the clitoral shaft, the labia majora gradually cover the clitoris after ~14 weeks. The labia minora form at ~8 weeks from the ridges of thick-skin epithelium that flank the genital exit. They are continuous ventrolaterally with the clitoral hood and ventromedially with the apex of the cavernous body. Dorsally, their dense subcutaneous mesenchymal core extends to the anal canal. Between 8 and 14 weeks, the urethra lengthens axially, while the vaginal vestibule extends ventrally. In this period, the urethral plate of female embryos is mitotically active but does not increase in volume, which suggests that it contributes to vestibular growth. In conclusion, we observed a temporal correlation between the development of the thick-skin epithelium and that of the external genitals, with a distribution that is reminiscent of the dihydrotestosterone-sensitive skin.

Light and scanning electron microscope characterization of mandibular symphysis tissue as a functional adaptation in the mandible development of human fetuses.

When developing, the mandible presents great plasticity and contains condensed mesenchymal cells that develops into Meckel's cartilage, of which the anterior part forms the mandibular symphysis. Mandible human development studies focus on investigating whether the beginning of mandibular fusion in fetal period is related to symphysis ossification and the tensions imposed on it, considering that tongue movements, mouth opening, and closing can be seen in fetuses. This research analyses tissue modifications during human mandibular symphysis growth using light and scanning electron microscopy to relate them to its functional structure. The study sample consisted of 12 human fetuses distributed into two groups: Group I (GI) of 10-14 weeks old and Group II (GII) of 20-24 weeks old. Fragments of mandibular symphysis were removed en bloc together with the surrounding tissues to preserve the relation with adjacent structures. Decalcified specimens were prepared in semi-serial coronal sections 5-μm-thick and stained with hematoxylin and eosin, Masson՚s trichrome, Verhoeff, and Sirius red for histological analysis with light microscopy. Collagen fibers Type I or III and elastic fibers were quantified by volume fraction (Vv). Coronal sections of the GI and GII symphyseal region were submitted to scanning electron microscopy. Comparison between groups used independent t-test. Our study presents the different endochondral ossification stages in the anterior part of Meckel's cartilage in GI. Both groups showed abundantly vascularized mesenchymal tissue with intense cellular activity forming the mandibular symphysis, such as a source of new osteoblasts adjacent to the newly deposited bone matrix. Scanning electron microscopy analysis revealed an invasion of the bony trabecula in the transverse direction from the hemimandible, rectilinear in GI and sinuous in GII due to interdigitating bone process, promoting its ossification. In collagen Vv analysis was verified a prevalence of type I in GII and type III in GI, indicating a proportional relation between maturation and tissue arrangement. Functionally, the collagen and elastic fibers in the mandibular symphysis were arranged in a pantographic network, and the fibrillar interconnectivity clearly contributes to resilience capacity and efficiency of the force transfer. This study inferred the functional significance of the knowledge about the tissue composition of mandibular symphysis, and the importance of this tissue for surrounding structures. The mesenchymal tissue of mandibular symphysis participates in bone growth process, revealing an adaptation mechanism of mandibular symphysis in the fetal period investigated.

The development of the external genitals in female human embryos and foetuses. Part 2: Vaginal vestibule, anal canal, perineal raphe and perineal cutaneous muscles.

Concomitant with the rupture of the cloacal membrane, the perineal skin epithelium thickens (see accompanying article). In this study, we establish in female embryos and foetuses that the thick skin area divides into ventral and dorsal areas at ~14 weeks and gradually becomes restricted to the vaginal vestibule and anal canal thereafter. The dense mesenchymal core of the labia minora, which forms at ~8 weeks, extends dorsally to the anal canal as a midline reinforcement. The skin epithelium overlying this reinforcement is much thinner than the flanking 'thick skin', and is supported by an interrupted basement membrane, which implies epithelial-mesenchymal transformation of the thin midline epithelium and the subsequent establishment of the perineal raphe by the merging of the adjacent thick epithelium. Meanwhile, the anogenital distance in the perineum increases rapidly in length. Perhaps as a consequence, the labia minora cover only the ventral third of the vaginal vestibule at 20 weeks. The endodermal ducts of Bartholin's glands are identifiable at 7 weeks, while acini form at ~12 weeks. The vestibular bulbs become identifiable at ~10 weeks and form vascular networks after ~14.5 weeks. After the rupture of the cloacal membrane, the diameter of the junction of the dorsal cloaca with the anal canal is just a pinhole but widens dorsoventrally after the 7th week. The cutaneous muscles of the perineal area form as a ventrally open U-shaped mesenchymal mass, from which the anal sphincter and bulbospongiosus muscle develop. In conclusion, our findings show that thick skin epithelium persists in the vaginal vestibule and anal canal.

No birth-associated maternal mortality in Japanese macaques (Macaca fuscata) despite giving birth to large-headed neonates

Human fetuses at term are large relative to the dimensions of the maternal birth canal, implying that their birth can be associated with difficulties. The tight passage through the human birth canal can lead to devastating outcomes if birth becomes obstructed, including maternal and fetal death. Although macaques have to accommodate similarly large fetuses, relative to their maternal birth canals, it was not known whether macaque mothers face birth difficulties similar to humans. Based on 27 y of demographic data from a semi-free-ranging, closely monitored population of Japanese macaques (Macaca fuscata), we found no birth-associated mortality in macaques. This differs from the situation in many human populations. We suggest three nonmutually exclusive hypotheses to explain these observations. i) The macaque fetal skull is similarly flexible as the human fetal skull. ii) The macaque pelvis and connective tissue show greater flexibility during birth. iii) The interplay between macaque pelvic shape and birth dynamics is smoother and incurs fewer complications than in humans.

Право человеческого эмбриона и плода на биобезопасность: актуальные вопросы правопонимания и правового регулирования

The article examines topical issues of legal understanding and legal regulation of the right of the human embryo and fetus to biosafety. The idea of forming the legal status of the human embryo and fetus is put forward, similar to the status of a born child with fundamental rights to life, health, dignity and biosafety. The assessment of the established legal approaches to solving such problems as the legal nature of the human embryo and fetus, their right to protection of their natural biological existence and development; protecting embryos and fetuses from abuse of biotechnology and genetic engineering. The author considers it important in the modern legal regulation of the use of biotechnologies to find a balance between rationality and humanism, which allows treating the embryo and fetus as a person, in respect of which an appropriate system of legal protection is being built against modern biological threats and challenges caused, among other things, by the unregulated development of biotechnologies.

Diabetes and Early Development: Epigenetics, Biological Stress, and Aging.

Pregestational diabetes, either type 1 or type 2 diabetes, induces structural birth defects including neural tube defects and congenital heart defects in human fetuses. Rodent models of type 1 and type 2 diabetic embryopathy have been established and faithfully mimic human conditions. Hyperglycemia of maternal diabetes triggers oxidative stress in the developing neuroepithelium and the embryonic heart leading to the activation of proapoptotic kinases and excessive cell death. Oxidative stress also activates the unfolded protein response and endoplasmic reticulum stress. Hyperglycemia alters epigenetic landscapes by suppressing histone deacetylation, perturbing microRNA (miRNA) expression, and increasing DNA methylation. At cellular levels, besides the induction of cell apoptosis, hyperglycemia suppresses cell proliferation and induces premature senescence. Stress signaling elicited by maternal diabetes disrupts cellular organelle homeostasis leading to mitochondrial dysfunction, mitochondrial dynamic alteration, and autophagy impairment. Blocking oxidative stress, kinase activation, and cellular senescence ameliorates diabetic embryopathy. Deleting the mir200c gene or restoring mir322 expression abolishes maternal diabetes hyperglycemia-induced senescence and cellular stress, respectively. Both the autophagy activator trehalose and the senomorphic rapamycin can alleviate diabetic embryopathy. Thus, targeting cellular stress, miRNAs, senescence, or restoring autophagy or mitochondrial fusion is a promising approach to prevent poorly controlled maternal diabetes-induced structural birth defects. In this review, we summarize the causal events in diabetic embryopathy and propose preventions for this pathological condition. KEY POINTS: · Maternal diabetes induces structural birth defects.. · Kinase signaling and cellular organelle stress are critically involved in neural tube defects.. · Maternal diabetes increases DNA methylation and suppresses developmental gene expression.. · Cellular apoptosis and senescence are induced by maternal diabetes in the neuroepithelium.. · microRNAs disrupt mitochondrial fusion leading to congenital heart diseases in diabetic pregnancy..

Comparative characteristics of the dimensions of the pons with the dimensions of the head in human fetes of different gestational age

Annotation. Malformations of human fetuses brains occur in 2-3 cases per 1000 pregnancies and are one of the most common reasons for termination of pregnancy, therefore prenatal diagnosis is extremely important and is aimed at further genetic testing of the fetus and detailed counseling of parents regarding the risk of recurrence. Anthropometric parameters of human fetuses heads allow monitoring the growth of the fetus, estimating the term of pregnancy and determining the method of birth of a pregnant woman. Therefore, the parameters of the head of human fetuses are one of the most important biological characteristics during prenatal research. The purpose of our scientific work is to determine the dimensions of the pons in human fetuses of different gestational ages and compare them with the dimensions of the head. Anatomical research was conducted on 146 human fetuses from 9-10 to 39-40 weeks of gestation. The material for the study was obtained from the maternity hospitals of the city of Vinnytsia and from the communal non-profit enterprise “Vinnytsia Regional Pathological Bureau of the Vinnytsia Regional Council”, and the study was conducted on stillborns who died from various causes not related to brain diseases in relatively healthy mothers. Head circumference, head height, longitudinal and transverse dimensions of the head, pons height, pons width, pons thickness were measured using a ShTs-125 caliper. Statistical processing of digital values was performed using the standard Statsoft software package “Statistica 6.0” on a personal computer using Microsoft Excel 2016, Kolmagorov-Smirnov and Shapiro-Wilk test indicators were determined and histograms were built based on them for visual assessment of the distribution of features. The head circumference of human fetuses of 39-40 weeks compared to fetuses of 9-10 weeks became 5.2 times larger, the longitudinal size of the head – 5 times, the transverse size of the head – 4.9 times, the height of the head – 3.6 times (p&lt;0.01). The height of the pons in human fetuses of 39-40 weeks compared to fetuses of 9-10 weeks became 3.8 times greater, thickness – 3.6 times, width – 3.1 times (p&lt;0.01).

Sex differences in human pre-gastrulation embryos.

Human fetuses exhibit notable sex differences in growth rate and response to the intrauterine environment, yet their origins and underlying mechanisms remain uncertain. Here, we conduct a detailed investigation of sex differences in human pre-gastrulation embryos. The lower methylation and incomplete inactivation of the X chromosome in females, as well as the sex-specific cell-cell communication patterns, contribute to sex-differential transcription. Male trophectoderm is more inclined toward syncytiotrophoblast differentiation and exhibits a stronger hormone secretion capacity, while female trophectoderm tends to retain cytotrophoblast program with stronger mitochondrial function as well as higher vasculogenesis and immunotolerance signals. Male primitive endoderm initiates the anterior visceral endoderm transcriptional program earlier than females. The cell cycle activities of the epiblast and primitive endoderm are higher in males compared to females, while the situation is opposite in the trophectoderm. In conclusion, our study provides in-depth insights into the sex differences in human pre-gastrulation embryos and contributes to unraveling the origins of the sex differences in human fetal development.

Amnioinfusion by lactated Ringer’s solution via may reduce the toxicity on the exposed nerve tissue in spina bifida

Spina bifida is one of the most common developmental fetal malformations. It is a defect in dorsal spinal elements that exposes nerve tissue to the external environment – the amniotic fluid – leading to toxic exposure. By reviewing the development of fetal therapy, the physiopathology, and the mechanism of spina bifida, we hypothesize that the repetitive early replacement of the amniotic fluid with lactated Ringer’s solution via amnioinfusion may reduce toxicity to the exposed nerve tissue. Studies in fetal rat models suggest that amniotic fluid is toxic to the exposed spinal cord by an inflammatory response. Given the similarity between lactated Ringer’s solution and amniotic fluid, this replacement could mitigate toxicity without altering the intrauterine environment. Randomized controlled trials in animals and human fetuses are needed to test this hypothesis. If effective, this approach could benefit conservative couples and be applicable in low-income settings, improving outcomes after fetal surgery.

The human foetus as ‘donor’ of tissues and organs

The possibility of using the foetus as a ‘donor’ of tissues and organs is coming up more and more frequently in the field of transplantation and is being considered by numerous institutional and national ethics committees, as well as by international bodies that have drawn up and are drawing up guidelines.