PubMed HealthSearch

PubMed · 9283739

"Gestational age"?

Abstract

The source did not provide an abstract. Follow the original record for more information.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R O'Rahilly. 1997. "Gestational age"?. https://doi.org/10.1002/(sici)1098-2353(1997)10%3A5%3C367%3A%3Aaid-ca18%3E3.0.co%3B2-i

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Three-dimensional ultrasonographic assessments of fetal development.

OBJECTIVE: To visualize fetal surface anatomic structures in advancing gestation by use of three-dimensional ultrasonography with a specially developed abdominal three-dimensional transducer. METHODS: One hundred six normal fetuses from 9 to 40 weeks' gestation were studied with a specially developed abdominal three-dimensional transducer (3.5 MHz). This imaging system can provide conventional two-dimensional ultrasonography images and also can generate within seconds high-quality three-dimensional images in the surface and transparent modes with no need for an external workstation. We determined percentage of surface anatomic structures visualized at each trimester using two-dimensional and three-dimensional ultrasonography. RESULTS: The number and the clarity of surface anatomic structures increased from the first to the third trimester of pregnancy. The image quality was less distinct in the first trimester because of the small fetal size. The ability to view the fetal face, hands, and feet was better with three-dimensional ultrasonography than with two-dimensional ultrasonography in the first trimester (P < .05), whereas fetal genitals were viewed better with two-dimensional ultrasonography than with three-dimensional ultrasonography in the second and third trimesters (P < .05). CONCLUSION: Three-dimensional ultrasonography provides a new means of visualizing surface anatomic structures of the fetus in utero. Our results suggest that three-dimensional ultrasonography has the potential to be a supplement to two-dimensional ultrasonography and should be useful in evaluating fetal abnormalities in high-risk pregnancies.

Embryonic and Fetal Development

Anatomical relationships between testis and epididymis during the fetal period in humans (10-36 weeks postconception).

OBJECTIVE: To determine the anatomy of the epididymis and its relationship with the testis during the fetal period in normal individuals. METHODS: We studied bilaterally 146 testes and epididymides taken from 73 normal fresh human fetuses ranging in age from 10 to 36 weeks postconception. The epididymal anatomy was classified in six types: type I: the epididymis is connected to the testis by its head and tail and the epididymal body is separated from the testis; type II: the epididymis is completely attached to the testis; type III: the epididymis is attached to the testis only by its head; type IV: the epididymis is attached to the testis only by its tail; type V: the epididymis is completely detached from the testis; type VI: segmental atresia of the epididymis. RESULTS: Normal epididymal anatomy, considered type I and type II, was found in 89.72% and in 7.53% of the cases, respectively. Type III and type IV epididymal anatomy was found in only 2.05% and 0.68% of the cases, respectively. We did not find types V and VI epididymal abnormalities. CONCLUSIONS: Our results show that irrespective of testicular position during the fetal period, the incidence of epididymal abnormalities in normal fetuses is very low (2.75%) when compared with previous reports in patients with cryptorchidism and/or with a patent processus vaginalis (36-79%).

Embryonic and Fetal Development

Transient fetal structure, the gangliothalamic body, connects telencephalic germinal zone with all thalamic regions in the developing human brain.

Previous studies reported that telencephalic proliferative zones contribute to the development of the pulvinar thalamic nucleus in the human brain (Rakic and Sidman [1969] Z. Anat. Entwicklungsgesch. 129:53-82). The present study examined their possible contribution to the development of other thalamic nuclei. Postmortem brain tissue from human fetuses ranging between 10.5 and 40 weeks of gestation (wg) was processed by Nissl staining, Golgi impregnation, and MAP2 (microtubule-associated protein 2) immunocytochemistry. The gangliothalamic body, suggested to serve as a conduit for cells migrating from the ganglionic eminence to the thalamus, was found in the period from 15 to 34 wg in all rostrocaudal thalamic regions, particularly at the level of the anterior nuclear complex, mediodorsal and pulvinar nucleus, and in addition, the lateral geniculate nucleus. In Nissl-stained sections, the gangliothalamic body is a thin cellular layer situated beneath the thalamic surface, near the telencephalo-diencephalic junction. In Golgi- and MAP2-stained sections, it is a stream of mostly bipolar cells extending from the ganglionic eminence to the medial thalamus. In addition, MAP2-immunoreactivity confirms the neuronal nature of its cells. The present study further supports the hypothesis that certain neurons migrate from the ganglionic eminence to the thalamus through the transient gangliothalamic body during fetal development. Moreover, our data indicate that both the association (mediodorsal and pulvinar), as well as the anterior (limbic) and specific relay nuclei are potential recipients of the telencephalic neurons.

Embryonic and Fetal Development