Biological and behavioral determinants of fertility in Tierra del Fuego

Abstract

The reproductive history of 182 women in postreproductive life or near menopause from the Chilean part of Tierra del Fuego was traced back by means of familial interviews. These postmenopausal women represent the population since almost the beginning of the settlement, and their reproductive years were spent on the island. Path analysis was applied to analyze fertility determinants of these women and to propose a complex model of interconnections among factors. The reproductive history of these women is characterized by a long fertile span, a short childbearing period, and low fertility. Age at menarche is relatively late, and the age of the women at first birth is mainly determined by their late age at marriage. The use of contraception is related to both spacing and stopping behaviors. The late age of women at marriage, the rhythm of conception, and practices of contraception are proposed as the main determinants of fertility in Tierra del Fuego.

Genetics of age at menarche: a systematic review

“…There is a secular trend in the mean age at menarche with a steady decline over the last several decades (Hwang et al, 2003;Herman-Giddens, 2007). Age at menarche has important implications in female fertility (McKibben and Poston, 2003;Pascual et al, 2005) and, furthermore, it may serve as an indicator of possible health complications in later life. Earlier menarche is associated with an increased risk of some diseases, such as breast cancer (Schatzkin et al, 1987;Peeters et al, 1995), gynecological cancers (Marshall et al, 1998;Fujita et al, 2008) and various cardiovascular diseases (Cooper et al, 1999;Lakshman et al, 2009).…”

Evolutionary demography of age at last birth: integrating approaches from human behavioural ecology and cultural evolution

“…Given that ALB is often a stronger predictor of reproductive success than more commonly used proxies such as onset of menarche or AFB [ 2 , 70 ], we anticipate increased interest in this topic. ALB, like lifetime fertility, has been showing declines in many populations over time [ 71 , 72 ] and, indeed, may be one of the most important contributions to the reductions in fertility associated with global fertility transition [ 72 , 73 ]. Consistent with this, our data show clear declines in ALB, which seem to have arisen independently of the Chinese fertility policy.…”

Edad materna y paridad en la población de Tierra del Fuego a mediados del siglo XX: Comparación con la Isla de Pascua

“…En Tierra del Fuego el control de la fecundidad se realizó a lo largo del siglo XX espaciando los nacimientos y con una edad temprana a la última maternidad (Pascual et al 2005(Pascual et al , 2006. El modelo obtenido, a partir del estudio mediante encuestas, de una muestra de mujeres fecundas, que habían finalizado su intervalo fértil, evidenció un tamaño reducido de la progenie (algo más de tres hijos) y un intervalo fecundo promedio corto, de unos nueve años, que serían el resultado de una regulación de la fecundidad limitándola y espaciándola.…”