BACKGROUND Family-planning policies have focused on contraceptive approaches to avoid unintended pregnancies, postpone, or terminate pregnancies and mitigate population growth. These policies have contributed to significantly slowing world population growth. Presently, half the countries worldwide exhibit a fertility rate below replacement level. Not including the effects of migration, many countries are predicted to have a population decline of >50% from 2017 to 2100, causing demographic changes with profound societal implications. Policies that optimize chances to have a child when desired increase fertility rates and are gaining interest as a family-building method. Increasingly, countries have implemented child-friendly policies (mainly financial incentives in addition to public funding of fertility treatment in a limited number of countries) to mitigate decreasing national populations. However, the extent of public spending on child benefits varies greatly from country to country. To our knowledge, this International Federation of Fertility Societies (IFFS) consensus document represents the first attempt to describe major disparities in access to fertility care in the context of the global trend of decreasing growth in the world population, based on a narrative review of the existing literature. OBJECTIVE AND RATIONALE The concept of family building, the process by which individuals or couples create or expand their families, has been largely ignored in family-planning paradigms. Family building encompasses various methods and options for individuals or couples who wish to have children. It can involve biological means, such as natural conception, as well as ART, surrogacy, adoption, and foster care. Family-building acknowledges the diverse ways in which individuals or couples can create their desired family and reflects the understanding that there is no one-size-fits-all approach to building a family. Developing education programs for young adults to increase family-building awareness and prevent infertility is urgently needed. Recommendations are provided and important knowledge gaps identified to provide professionals, the public, and policymakers with a comprehensive understanding of the role of child-friendly policies. SEARCH METHODS A narrative review of the existing literature was performed by invited global leaders who themselves significantly contributed to this research field. Each section of the review was prepared by two to three experts, each of whom searched the published literature (PubMed) for peer reviewed full papers and reviews. Sections were discussed monthly by all authors and quarterly by the review board. The final document was prepared following discussions among all team members during a hybrid invitational meeting where full consensus was reached. OUTCOMES Major advances in fertility care have dramatically improved family-building opportunities since the 1990s. Although up to 10% of all children are born as a result of fertility care in some wealthy countries, there is great variation in access to care. The high cost to patients of infertility treatment renders it unaffordable for most. Preliminary studies point to the increasing contribution of fertility care to the global population and the associated economic benefits for society. WIDER IMPLICATIONS Fertility care has rarely been discussed in the context of a rapid decrease in world population growth. Soon, most countries will have an average number of children per woman far below the replacement level. While this may have a beneficial impact on the environment, underpopulation is of great concern in many countries. Although governments have implemented child-friendly policies, distinct discrepancies in access to fertility care remain.

中文翻译：

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全球生育率下降及其对计划生育和家庭建设的影响：基于文献叙述性回顾的 IFFS 共识文件。


背景 计划生育政策侧重于避孕方法，以避免意外怀孕、推迟或终止妊娠并减缓人口增长。这些政策导致世界人口增长显著放缓。目前，全球一半国家的生育率低于更替水平。不包括移民的影响，预计从 2017 年到 2100 年，许多国家的人口将下降 >50%，从而导致具有深远社会影响的人口变化。在需要时优化生育机会的政策可以提高生育率，并作为一种建立家庭的方法越来越受到关注。越来越多的国家实施了儿童友好政策（主要是财政激励措施，除了少数国家的生育治疗公共资金外），以缓解全国人口减少的情况。然而，各国在儿童福利方面的公共支出程度差异很大。据我们所知，这份国际生育协会联合会 （IFFS） 共识文件代表了在世界人口增长放缓的全球趋势背景下首次尝试描述在世界人口增长放缓的背景下获得生育保健方面的主要差异，基于对现有文献的叙述性回顾。客观和基本原理 家庭建设的概念，即个人或夫妇创建或扩大家庭的过程，在计划生育范式中基本上被忽视了。家庭建设包括希望生孩子的个人或夫妇的各种方法和选择。它可能涉及生物手段，例如自然受孕，以及 ART、代孕、收养和寄养。 家庭建设承认个人或夫妇可以以多种方式创建他们想要的家庭，并反映了这样一种理解，即建立家庭没有放之四海而皆准的方法。迫切需要为年轻人制定教育计划，以提高建立家庭的意识并预防不孕症。提供了建议并确定了重要的知识差距，以使专业人士、公众和政策制定者全面了解儿童友好政策的作用。检索方法 受邀的全球领导者对现有文献进行了叙述性回顾，他们本身对该研究领域做出了重大贡献。综述的每个部分由两到三名专家编写，每位专家都检索已发表的文献 （PubMed） 以查找同行评审的全文和综述。所有作者每月讨论一次，评审委员会每季度讨论一次。最终文件是在混合邀请会议期间所有团队成员进行讨论后准备的，并达成了完全共识。结果 自 1990 年代以来，生育保健的重大进步极大地改善了建立家庭的机会。尽管在一些富裕国家，高达 10% 的儿童是通过生育保健出生的，但获得保健的机会存在很大差异。不孕症治疗对患者的高昂费用使大多数人负担不起。初步研究表明，生育保健对全球人口的贡献越来越大，并为社会带来相关的经济利益。更广泛的影响 在世界人口增长迅速下降的背景下，生育保健很少被讨论。 很快，大多数国家每名妇女的平均生育子女数将远低于更替水平。虽然这可能对环境产生有益影响，但人口不足在许多国家/地区都引起了极大的关注。尽管政府实施了儿童友好政策，但在获得生育保健方面仍然存在明显差异。