RESUMO
En el presente artículo se analizan los efectos de la postergación de la maternidad en tres ámbitos: i) demográfico, ii) clínico y iii) biológico. Desde luego, la literatura demográfica existente procede fundamentalmente de países con un buen grado de desarrollo, pero se ha realizado un esfuerzo por reunir la mayor cantidad de datos de países en desarrollo. Así se analiza la situación en Europa, EE.UU. y Latinoamérica para finalizar esta sección con la realidad específica en Chile. Desde el punto de vista clínico, se pone especial interés en los cambios que experimenta la probabilidad de embarazo por ciclo (definida como fecundabilidad) y la fertilidad en general. En los aspectos perinatológicos se enfatiza el incremento de frecuencia de la muerte fetal in útero temprana (aborto espontáneo) y tardía con especial mención de algunas patologías (frecuencia del síndrome de Down y otros). Se establece además la frecuencia significativamente mayor de bajo y muy bajo peso de nacimiento, necesidad de hospitalización del recién nacido (morbilidad perinatal) así como el efecto sobre la mortalidad neonatal.Biológicamente la postergación de la maternidad tiene su correlato en la pérdida de reserva ovárica y la disminución de la calidad ovocitaria que involucra un aumento en la incidencia de fallas de fecundación y embriones con bajo potencial de desarrollo y aneuploidías dependientes fundamentalmente de la edad materna. También se hace mención a algunos aspectos del envejecimiento uterino y sus consecuencias en el desarrollo y función placentaria. El enfoque se centra fundamentalmente en la mujer, pero incluye aspectos de la contribución masculina a esta temática.
This article analyzes the effects of the postponement of maternity in three areas: i) demographic, ii) clinical and perinatological and iii) biological. Of course, the existing demographic literature comes primarily from well-developed countries, but an effort has been made to collect as much data from developing countries. The situation in Europe, the U.S. and Latin America is analyzed to end this section with the specific reality in Chile. From the clinical point of view, special interest is placed on changes in the probability of pregnancy by cycle (defined as fecundability) and fertility in general. In the perinatological aspects, the increased frequency of early fetal death (spontaneous abortion) and stillbirth is emphasized, with special mention of some pathologies (frequency of Down syndrome and others). It is also stressed the significant higher frequency of low and very low birth weight, the need newborn hospitalization (perinatal morbidity), as well as the effects on neonatal mortality. Biologically, the postponement of maternity has its correlation in the loss of ovarian reserve and the decrease in oocyte quality that involves an increased incidence of fertilization failure and embryos with low potential for development and aneuploidies, mainly dependent on maternal age. Some aspects of uterine aging and its consequences on placental development and function are also mentioned. The discussion is mainly focused on women, but includes some aspects of the male contribution to this issue
Assuntos
Humanos , Feminino , Idade Materna , Tomada de Decisões , Comportamento Reprodutivo , Resultado da Gravidez , Fertilidade , Fatores SociodemográficosRESUMO
Background: Postponement of motherhood is one of the most striking sociodemographic changes of modernity. Aim: To evaluate the age of primiparous women giving birth at a public hospital in Santiago, Chile. Material and Methods: Retrospective study, assessing the age and nationality of all women whose delivery occurred between 2009 and 2017 in a single hospital. Results: A total of 49,254 deliveries were registered: 43% were in primiparous women (73% Chilean and 27% foreign women). The proportion of foreign women increased from 12% in 2009 to more than 60% of total deliveries in 2017. Four percent of primiparous women were aged over 35 years of age and there was a steady increase in the age increase of primiparous women in the nine years of study. There was a higher proportion of normal-weight newborns among foreign women compared to their Chilean counterparts (86 and 81% respectively). Conclusions: In this sample of women attended at a public hospital, a steady increase in the age at first delivery was noted in a period of nine years. There was also a constant increase in the proportion of foreign women giving birth.