The possible role of selenium status in adverse pregnancy outcomes.

The present study reviews the possible role of Se status during pregnancy regarding adverse pregnancy outcomes, with emphasis on those related to diminished antioxidant activity and increased oxidative stress. Studies have reported that Se could play an important role in adverse outcomes such as miscarriages, neural tube defects, diaphragmatic hernia, premature birth, low birth weight, pre-eclampsia, glucose intolerance and gestational diabetes. Also, low Se status has been associated with adverse outcomes among HIV-infected pregnant women and their offspring. Nevertheless, the function of Se in the aetiology of pregnancy complications is yet to be elucidated. Available evidence presents the following limitations: most study designs do not allow conclusions about causal relationships; study populations, selection of subjects, research setting, procedures for defining sample size and analytical methods are often poorly described; many studies fail to adjust for important confounding variables. In addition, population studies assessing the relationship between Se intake during pregnancy and health outcomes are scarce. Further research is still needed to clarify the role of Se status in adverse pregnancy outcomes, especially those related to augmented oxidative stress.

Gestações sucessivas na adolescência / Successive pregnancies in adolescence

Buscou-se, por meio de uma revisão bibliográfica de publicações científicas no período de 1980 a 2005, levantar conhecimentos produzidos sobre a ocorrência de gestações sucessivas na adolescência. Inicialmente, investigou-se a dinâmica reprodutiva da população adolescente e, em seguida, é apresentada a revisão de vários estudos que tratam das gravidezes recorrentes dessas jovens, procurando, inclusive, elencar os vários conceitos usados para especificar o fenômeno. Foi localizada pequena produção científica acerca do tema, contudo, nos trabalhos encontrados foram detectados dados importantes que concorrem para o entendimento do fenômeno, especialmente aqueles referentes ao seu número, à grande possibilidade de sua repetição na ausência de recursos protetores ao pós-parto, à escolaridade das jovens grávidas, ao seu retorno à escolarização e ao uso adequado que elas fazem de métodos anticoncepcionais. Entretanto, esses dados devem ser relativizados uma vez que vários autores descrevem altos índices de gestações recorrentes de adolescentes quando em parceria sexual fixa, quer sejam casadas ou em uniões consensuais. Nesse caso se pode pensar que essa população, após a primeira gravidez, definitivamente assume uma vida conjugal estável, modificando consideravelmente o perfil clássico da "adolescente grávida"(AU)

This study aimed to survey the knowledge produced on the occurrence of successive pregnancies in adolescence, through a bibliographic review of scientific works published between 1980 and 2005. First, we investigate the reproductive dynamics of the youth population; then, we present the review of several studies that deal with successive pregnancies in adolescence, listing the several concepts used to specify the phenomenon. Very few scientific productions about the theme were found; however, they provided important data for the understanding of this phenomenon, specially concerning its number, the likelihood of its repetition in the absence of resources to protect the period after delivery, the education level of the pregnant youths, their return to school, and the adequate use they make of contraceptive methods. Nevertheless, these data can be questioned, since several authors describe high indexes of recurrent pregnancies of adolescents when they have a stable partner, whether they are married or in consensual unions. It is possible to think, in this case, that this population, after the first pregnancy, definitively assumes a stable conjugal life, considerably modifying the classic profile of the "pregnant adolescent".(AU)