Normal embryonic development of human heart is studied with special emphasis to the formation of atrioventricular and ventriculoarterial connections and their significance in congenital heart disease. Twenty nine human embryos and 8 chick embryos are used in this study. Human embryos are analyzed by reconstruction of serial section slides and chick embryos are microdissected and examined by scanning electron microscopy. In the early cardiac development (Streeter horizon 12), bulbo-ventricular fold divided two ventricles first. The atrioventricular canal is incompletely divided and the canal was in contact neither with septum primum nor with ventricular septal crest. Infundibular and truncal septa were not seen. The division of A-V canal was observed during the stages 14-15. Septation of truncus arteriosus (Streeter horizon 15-17) was followed by septation of bulbus cordis (Streeter horizon 16-17). The shortening of mitral-aortic distance and downward left shift of aortic valve occured after the trunco-infundibular septation and finally the secondary interventricular formen closed at the end of seventh week (Streeter horizon 20-21).
Humans ; Chick Embryo ; Animals

Background: In vitro fertilization cycle often have redundant embryos. These redundant embryos will be frozen and used for the next embryos transfer. Objective: To evaluate clinical pregnancy rate and factors affecting pregnancy outcomes after frozen embryos transfer. Subjects and method: 1013 frozen embryos were cultured until day 2 or 3 and then frozen by the slow freezing procedure. The embryos were thawed and transferred when indicated. Data was processed by SPSS software. Results: The mean age of patients was 32.81 +/- 5.4 years. 70% of patients were infertile due to ovarian diseases. Clinical pregnancy rate after frozen embryos transfer was 28.1%, pregnancy rate on day 3 higher than on day 2, pregnancy rate on day 1 was 40%. Miscarriage rate was 22.3%, multiple pregnancies was 44.4%. Age of patient did not affect pregnancy outcome. Endometrial thickness, quality of embryos had affected pregnancy rate. Conclusions: Clinical pregnancy rate after frozen embryos transfer was 28.1%. Quality of embryo, endometrial thickness and time of transfer had affected pregnancy rate after frozen embryos.
Frozen embryo ; pregnancy

No abstract available.
Animals ; Chick Embryo* ; Nicotine*

Embryo Research ; Humans

No abstract available.
Embryo Transfer* ; Embryonic Structures* ; Fertilization in Vitro*

No abstract available.
Embryo Transfer* ; Embryonic Structures* ; Fertilization in Vitro* ; Pregnancy*

No abstract available.
Embryo Transfer* ; Embryonic Structures* ; Estradiol* ; Fertilization in Vitro*

No abstract available.
Embryo Transfer* ; Embryonic Structures* ; Fertilization in Vitro* ; Pregnancy*

In comparison with their in vivo counterparts, the in vitro produced mammalian embryos had markedly lower rates of morula/blastocyst development and pregnancy after transfer to the recipients. Things became even worse in the cloned embryos. This necessitates improvement of the embryo culture system. Co-culture of embryos with different types of somatic cells was found beneficial for embryo development in vitro and many studies have been conducted in this area in recent years. In this paper, recent developments and the authors' own work in studies of co-culture of early mammalian embryos with somatic cells were reviewed, with emphasis on the effects of cell type, stage of estrous cycle and number of passages of somatic cells and supplement of serum on embryo development, and the mechanisms by which co-culture promote embryo development. The recent developments are summarized as follows: 1. Somatic cells of both homogeneous and heterogeneous origins can be used for co-culture of mammalian embryos, with similar developmental rates. 2. Supplementation of animal serum at appropriate concentrations improved the somatic cell growth and consequently the development of embryos in co-culture. 3. The estrous cycle stages of oviduct epithelial cells used for co-culture had no effect on the development of embryos. 4. Over-passaging of somatic cells reduced their efficiency in promoting development of the co-cultured embryos. In conclusion, studies have shown that co-culture overcame the block of embryo development in vitro and improved embryo quality with increased rates of implantation and pregnancy, but many problems remain to be solved on its influencing factors and mechanisms of action.
Animals ; Coculture Techniques ; methods ; Embryo Culture Techniques ; methods ; Embryo, Mammalian ; physiology ; Humans

OBJECTIVE: To study the clinical outcomes of single frozen-thawed blastocyst transfer cycles according to the hatching status of frozen-thawed blastocysts. METHODS: Frozen-thawed blastocysts were divided into three groups according to their hatching status as follows: less-than-expanded blastocyst (≤EdB), hatching blastocyst (HgB), and hatched blastocyst (HdB). The female age and infertility factors of each group were evaluated. The quality of the single frozen-thawed blastocyst was also graded as grade A, tightly packed inner cell mass (ICM) and many cells organized in the trophectoderm epithelium (TE); grade B, several and loose ICM and TE; and grade C, very few ICM and a few cells in the TE. The clinical pregnancy and implantation rate were compared between each group. The data were analyzed by either t-test or chi-square analysis. RESULTS: There were no statistically significant differences in average female ages, infertility factors, or the distribution of blastocyst grades A, B, and C in each group. There was no significant difference in the clinical pregnancy and implantation rate of each group according to their blastocyst grade. However, there was a significant difference in the clinical pregnancy and implantation rate between each group. In the HdB group, the clinical pregnancy and implantation rate were similar regardless of the blastocyst quality. CONCLUSION: There was an effect on the clinical outcomes depending on whether the blastocyst hatched during single frozen-thawed blastocyst transfer. When performing single frozen-thawed blastocyst transfer, the hatching status of the frozen-thawed blastocyst may be a more important parameter for clinical outcomes than the quality of the frozen-thawed blastocyst.
Blastocyst* ; Embryo Transfer* ; Epithelium ; Female ; Humans ; Infertility ; Pregnancy ; Retrospective Studies* ; Single Embryo Transfer ; Vitrification