RESUMO
Objective To investigate the real correlation between embryo density and developmental outcome of cleavage embryos on day 3 by adjusting covariates. Methods Data of 1196 embryos from 206 couples undergoing in vitro fertilization and embryo transfer(IVF-ET) treatment were retrospectively analyzed. Embryos were hypoxia-cultivated in a fixed 30 μl microdrop in culture dishes. Embryo quality on day 3 was evaluated and proportion of good quality cleavage embryos on day 3 was used as the endpoint. Maternal age, paternal age, antral follicles, level of anti-mullerian hormone (AMH), type of infertility, controlled ovarian stimulation(COS) protocol, length of stimulation, number of retrieved oocytes, and type of insemination were chosen as covariates. Results A total of 1196 embryos were included and analyzed. Three embryo densities were routinely used: 30 μl/ embryo [1 embryo/ (30 μl·drop)], 15 μl/ embryo [2 embryos / (30 μl·drop)] and 10 μl/ embryo [3 embryos/ (30 μl·drop)]. The number of embryos assigned into these three groups were 434, 646 and 116 embryos separately. The average proportion of good quality embryos on day 3 in 10 μl/ embryo group were lower than that in both 15 and 30 μl/ embryo group (29. 31% vs 40. 25%,P 0. 05). In the regression analysis, without adjusting any covariables, the good quality embryos rate on day 3 of the 10 μl/ embryo group was 43% lower than that of the 30 μl/ embryo group (0. 57, 95% CI 0. 32, 1. 03), and there was no statistical difference (P>0. 05). In the minimum-adjusted model 2 (adjusted the level of AMH and type of insemination), proportion of good quality embryos on day 3 in group of 10 μl/ embryo significantly decreased by 51% (0. 49, 95% CI 0. 27,0. 90, P < 0. 05) compared with that in group of 30 μl/ embryo. Conclusion In a 30 μl microdrop, compared with individual cul turing, group culturing with the density of 10 μl / embryo did not benefit the development of the cleavage embryos and 30 μl / embryo was the optimal embryo density.
RESUMO
O trabalho investiga a construção de rotinas compartilhadas num grupo de brinquedo de crianças de dois anos. Apóia-se no referencial psicoetológico, que reconhece a espécie humana como biologicamente sociocultural, e a cultura como seu nicho ontogenético. A criança é concebida como agente de criação e transmissão de cultura. Dois episódios lúdicos são analisados. Eles evidenciam a construção de uma rotina em que se arrastam grandes objetos ao longo de um pátio coberto. Há momentos de estabilidade e transformação em seu desenrolar. As crianças reconhecem a estrutura de participação na rotina e lhe adicionam inovações. A produção coletiva parece orientar o grupo no desdobramento de suas atividades. Os dados são interpretados como evidências de processos culturais na primeira infância. (AU)
This paper investigates the construction of shared routines in a playgroup of two-year-old children. It rests on a psychoethological approach, which recognizes the human being as a biologically social-cultural species, and culture as their ontogenetic niche. The child is conceived as an agent of creation and transmission of culture. Two ludic episodes are analyzed and they show the construction of a playful routine in which large objects are dragged along in a sheltered patio. There are moments of stability and transformation in the development of the task. Children recognize the structure of participation in the routine and add innovations to it. Collective production seems to guide the group in the development of the activities. The data are interpreted as evidence of cultural processes in early childhood. (AU)