Delayed parenthood and its influence on offspring health: What have we learned from the mouse model

Delayed parenthood is constantly increasing worldwide due to various socio-economic factors. In the last decade, a growing number of epidemiological studies have suggested a link between advanced parental age and an increased risk of diseases in the offspring. Also, poor reproductive outcome has been described in pregnancies conceived by aged parents. Similarly, animal studies showed that aging negatively affects gametes, early embryonic development, pregnancy progression and the postnatal phenotype of resulting offspring. However, how and to what extent parental age is a risk factor for the health of future generations is still subject to debate. Notwithstanding the limitation of an animal model, the mouse model represents a useful tool to understand not only the influence of parental age on offspring phenotype but also the biological mechanisms underlying the poor reproductive outcome and the occurrence of diseases in the descendants. The present review aims at i) providing an overview of the current knowledge from mouse model about the risks associated with conception at advanced age (e.g. neurodevelopmental and metabolic disorders), ii) highlighting the candidate biological mechanisms underlying this phenomenon, and iii) discussing on how murine-derived data can be relevant to humans.

Methods of Legal Regulation for Surrogacy in Ukraine and Abroad

Almost at the onset of surrogacy as a method of ART, it has been attracting the attention of society as the way to fulfill the issue of high priority – procreation and family. Surrogacy has become one of the main research objects of bioethics that studies the ethical and moral aspects of the use of new biological and medical technologies. The main issue of this article is the identification and comparative analysis of the features of the legal regulation of the method of surrogacy in Ukraine and other countries. The particular importance lies in specifying those prohibitions and restrictions, who they are applied to, and how they relate to the human right to procreation. The comparison to the laws of other countries that have a better legal surrogacy regulation will take place. The theoretical and practical significance of the work is reflected in the fact that the results can be used in the further theoretical development of the legal issues related to surrogacy as one of the methods of human assisted reproduction. The research made it possible to find out the basic terms that are used in the legal regulation of surrogacy. In the course of the research, it was found out that legal regulation of the use of the ART methods in the word, including surrogacy, varies depending on the jurisdiction. Each country has their laws. Nowadays it is possible to divide legal regulation of the use of the surrogacy method into four basic legal regimes: – regime of permission; – regime of restriction; – regime of complete prohibition (in any form); – regime of uncertainty. Ukrainian legislation is considered to be very liberal in relation to surrogacy. Major types of surrogacy, including commercial surrogacy, are permitted and widely used. Moreover, in Ukraine, legislation does not allow traditional surrogacy, and also does not allow couples who do not have a registered marriage, single people, and same-sex couples, to use this method. It should also be borne in mind that the method of surrogacy can only be used for medical reasons. In Ukraine, taking into account the peculiarities of notarization, agreements (contracts) on commercial surrogacy should be preferably signed by a notary. However, in the legislative norms there is no direct reference to the notarized form of such an agreement.The obtained research results indicate that Ukrainian surrogacy legal regulation is lacking a special law and thus remains fragmented. According to the author, only through the adoption of a special law in Ukraine, it will be possible to make proper legal regulation of basic reproductive human rights, including the application of the method of surrogacy, the peculiarities of concluding surrogacy agreements, post-mortem human reproduction and delayed parenthood.

POST-TRANSITIONAL FERTILITY: THE ROLE OF CHILDBEARING POSTPONEMENT IN FUELLING THE SHIFT TO LOW AND UNSTABLE FERTILITY LEVELS

SummaryThis study discusses fertility trends and variation in countries that completed the transition from high to around-replacement fertility in the 1950s to 1980s, especially in Europe, East Asia and North America, and summarizes the key relevant findings for those countries with a more recent experience of fertility decline towards replacement level. A central finding is that there is no obvious theoretical or empirical threshold around which period fertility tends to stabilize. Period fertility rates usually continue falling once the threshold of replacement fertility is crossed, often to very low levels. While cohort fertility rates frequently stabilize or change gradually, period fertility typically remains unstable. This instability also includes marked upturns and reversals in Total Fertility Rates (TFRs), as experienced in many countries in Europe in the early 2000s. The long-lasting trend towards delayed parenthood is central for understanding diverse, low and unstable post-transitional fertility patterns. In many countries in Europe this shift to a late childbearing pattern has negatively affected the TFR for more than four decades. Many emerging post-transitional countries and regions are likely to experience a similar shift over the next two to three decades, with a depression of their TFRs to very low levels.

Paternal age and risk for schizophrenia

BackgroundPreviously reported associations between advancing paternal age and schizophrenia could be due to an increase in paternal germ cell mutations or be confounded by heritable personality traits associated with schizophrenia that result in delayed parenthood.AimsTo investigate this association while adjusting for personality traits related to poor social integration in the subjects.MethodA cohort of 50 087 adolescent males was followed up by record linkage to determine hospital admissions for schizophrenia between 1970 and 1996.ResultsAdvancing paternal age was associated with an increased risk of developing schizophrenia in a ‘dose-dependent’ manner. The adjusted odds ratio for each 10-year increase in paternal age was 1.3 (95% Cl 1.0–1.5; P=0.015).ConclusionsAdvancing paternal age is an independent risk factor for schizophrenia. Adjusting for social integration in subjects made little difference to this association, consistent with the hypothesis that advancing paternal age may increase liability to schizophrenia owing to accumulating germ cell mutations.