Aspectos biométricos de la fecundidad humana

Incluye BibliografíaTraducción de Zulma C. CamisaSe analiza a nivel microdemografico el fenomeno de la fecundidad, a traves de sus principales componentes, para despues reconstituirlo a partir de dichos componentes, por medio de la aplicacion de modelos matematicos. Los resultados a escala macrodemografica se comparan con las observaciones disponibles. Los componentes son 4: la fecundabilidad, la mortalidad intrauterina, el tiempo muerto fisiologico y la esterilidad, los cuales se analizan en detalle, pasando revista a numerosos estudios e investigaciones al respecto, efectuadas en Francia y en otros paise

Realizing a desired family size: When should couples start?

STUDY QUESTION Until what age can couples wait to start a family without compromising their chances of realizing the desired number of children? SUMMARY ANSWER The latest female age at which a couple should start trying to become pregnant strongly depends on the importance attached to achieving a desired family size and on whether or not IVF is an acceptable option in case no natural pregnancy occurs. WHAT IS KNOWN ALREADY It is well established that the treatment-independent and treatment-dependent chances of pregnancy decline with female age. However, research on the effect of age has focused on the chance of a first pregnancy and not on realizing more than one child. STUDY DESIGN, SIZE, DURATION An established computer simulation model of fertility, updated with recent IVF success rates, was used to simulate a cohort of 10 000 couples in order to assess the chances of realizing a one-, two- or three-child family, for different female ages at which the couple starts trying to conceive. PARTICIPANTS/MATERIALS, SETTING, METHODS The model uses treatment-independent pregnancy chances and pregnancy chances after IVF/ICSI. In order to focus the discussion, we single out three levels of importance that couples could attach to realizing a desired family size: (i) Very important (equated with aiming for at least a 90% success chance). (ii) Important but not at all costs (equated with a 75% success chance) (iii) Good to have children, but a life without children is also fine (equated with a 50% success chance). MAIN RESULTS AND THE ROLE OF CHANCE In order to have a chance of at least 90% to realize a one-child family, couples should start trying to conceive when the female partner is 35 years of age or younger, in case IVF is an acceptable option. For two children, the latest starting age is 31 years, and for three children 28 years. Without IVF, couples should start no later than age 32 years for a one-child family, at 27 years for a two-child family, and at 23 years for three children. When couples accept 75% or lower chances of family completion, they can start 4-11 years later. The results appeared to be robust for plausible changes in model assumptions. LIMITATIONS, REASONS FOR CAUTION Our conclusions would have been more persuasive if derived directly from large-scale prospective studies. An evidence-based simulation study (as we did) is the next best option. We recommend that the simulations should be updated every 5-10 years with new evidence because, owing to improvements in IVF technology, the assumptions on IVF success chances in particular run the risk of becoming outdated. WIDER IMPLICATIONS OF THE FINDINGS Information on the chance of family completion at different starting ages is important for prospective parents in planning their family, for preconception counselling, for inclusion in educational courses in human biology, and for increasing public awareness on human reproductive possibilities and limitations

Південноукраїнські історики та російська академічна еліта: етапи та напрямки співпраці у другій половині ХІХ – на початку XX ст.

У статті на широкій джерельній базі досліджено інфраструктурні та особисті зв’язки між південноукраїнськими істориками та академіками Санкт-Петербурзької (Російської) Академії наук впродовж другої половини ХІХ ст. – 1920-х років.The article, based on a great number of sources, researches the infrastructural and personal contacts between the historians of South Ukraine and academicians of the St.-Petersburg Academy of Sciences throughout the second half of the ХІХ century – 1920-ies

Long-term trends in the longevity of scientific elites: evidence from the British and the Russian academies of science.

National science academies represent intellectual elites and vanguard groups in the achievement of longevity. We estimated life expectancy (LE) at age 50 of members of the British Royal Society (RS) for the years 1670-2007 and of members of the Russian Academy of Sciences (RAS) for the years 1750-2006. The longevity of academicians was higher than that of their corresponding national populations, with the gap widening from the 1950s. Since the 1980s, LE in the RS has been higher than the maximum LE among all high-income countries. In each period, LE in the RS was greater than in the RAS, although since the 1950s it has risen in parallel in the two academies. This steep increase shared by academicians in Britain and Russia suggests that general populations have the potential for a substantial increase in survival to high ages

Rationales, design and recruitment for the Elfe longitudinal study

Background Many factors act simultaneously in childhood to influence health status, life chances and well being, including pre-birth influences, the environmental pollutants of early life, health status but also the social influences of family and school. A cohort study is needed to disentangle these influences and explore attribution. Methods Elfe will be a nationally representative cohort of 20 000 children followed from birth to adulthood using a multidisciplinary approach. The cohort will be based on the INSEE Permanent Demographic Panel (EDP) established using census data and civil records. The sample size has been defined in order to match the representativeness criteria and to obtain some prevalence estimation, but also to address the research area of low exposure/rare effects. The cohort will be based on repeated surveys by face to face or phone interview (at birth and each year) as well as medical interview (at 2 years) and examination (at 6 years). Furthermore, biological samples will be taken at birth to evaluate the foetal exposition to toxic substances, environmental sensors will be placed in the child's homes. Pilot studies have been initiated in 2007 (500 children) with an overall acceptance rate of 55% and are currently under progress, the 2-year survey being carried out in October this year. Discussion The longitudinal study will provide a unique source of data to analyse the development of children in their environment, to study the various factors interacting throughout the life course up to adulthood and to determine the impact of childhood experience on the individual's physical, psychological, social and professional development

Further sociological contributions to family planning research

Leridon Henri. Further sociological contributions to family planning research. In: Population, 28ᵉ année, n°6, 1973. pp. 1223-1224

Osvald Hugo — The Earth can feed us; Laffin John — The Hunger to come

Leridon Henri. Osvald Hugo — The Earth can feed us; Laffin John — The Hunger to come. In: Population, 23ᵉ année, n°3, 1968. p. 562

Pasquier A. — Éléments de calcul des probabilités et théorie des sondages.

Leridon Henri. Pasquier A. — Éléments de calcul des probabilités et théorie des sondages.. In: Population, 24ᵉ année, n°6, 1969. p. 1235