Mapping Research in Assisted Reproduction Worldwide
Authors: García D. , Massucci Francesco Alessandro , Mosca Alessandro , Ràfols Ismael , Rodríguez A. , Vassena R. 
Published: April 2019

Study question: What are the current trends of research in Human Assisted Reproduction around the world? Summary answer: USA is the leading country, followed by the UK, China, France and Italy. The largest research area is &ldquo;laboratory techniques&rdquo;, although other areas such as &ldquo;public health&rdquo;, &ldquo;quality, ethics and law&rdquo; and &ldquo;female factor&rdquo; are gaining ground worldwide. What is known already: Scientific research, especially in health and medical sciences, aims at addressing specific needs that society (and, especially, patients) perceives as pressing. One of the main challenges for policymakers and research funders alike is therefore to align research priorities to societal needs. We can thus think of research agendas in terms of a demand side (societal needs) and a supply side (research outputs). Research output in Human Assisted Reproduction has expanded in the past years, as indicated by the increasing number of scientific publications in indexed journals in this area. Nevertheless, no map of research related to assisted reproduction has been produced so far, hindering the identification of potential areas of improvement and need. Study design, size, duration:&nbsp; 26,000+ scientific publications (articles, letters, and reviews) on Human Assisted Reproduction produced worldwide between 2005 and 2016 were analyzed. These publications were indexed in PubMed or obtained from reference list of indexed publications included in the analysis.Participants/materials, setting, methods: The corpus of publications was obtained by combining the MeSH terms: &ldquo;Reproductive techniques&rdquo;, &ldquo;Reproductive medicine&rdquo;, &ldquo;Reproductive health&rdquo;, &ldquo;Fertility&rdquo;, &ldquo;Infertility&rdquo;, and &ldquo;Germ cells&rdquo;. Then it was analyzed by means of text mining algorithms (Topic Modeling (TM) based on Latent Dirichlet Allocation (LDA)), in order to obtain the main topics of interest. Finally, these categories were analyzed across world regions and time. Main results and the role of chance:&nbsp; We identified 44 main topics, which were further grouped in 11 macro categories, form larger to smaller: &ldquo;laboratory techniques&rdquo;, &ldquo;male factor&rdquo;, &ldquo;quality, ethics and law&rdquo;, &ldquo;female factor&rdquo;, &ldquo;public health and infectious diseases&rdquo;, &ldquo;basic research and genetics&rdquo;, &ldquo;pregnancy complications and risks&rdquo;, &ldquo;general infertility and ART&rdquo;, &ldquo;psychosocial aspects&rdquo;, &ldquo;cancer&rdquo;, and &ldquo;research methodology&rdquo;. The USA was the leading country in number of publications, followed by the UK, China, France and Italy. Interestingly, research contents in high income countries is fairly homogeneous across macro-categories, and it is dominated by &ldquo;laboratory techniques&rdquo; in Western and Southern Europe, and by &ldquo;quality, ethics and law&rdquo; in North America, Australia and New Zealand. In middle income countries we observe that research is mainly performed on &ldquo;male factor&rdquo;, and noticeably less on &ldquo;female factor&rdquo;. Finally, research on &ldquo;public health and infectious diseases&rdquo; predominates in low-income countries. Regarding temporal evolution of research, &ldquo;laboratory techniques&rdquo; is the most abundant topic on a yearly basis, and relatively constant over time. However, since production in most of the other categories is increasing, the relative contribution of this research category is actually decreasing. Publication is especially increasing in &ldquo;public health and infectious diseases&rdquo; (in all world regions, but especially in low income countries), &ldquo;quality, ethics and law&rdquo; (high income countries), and &ldquo;female factor&rdquo; (middle income countries). Limitations, reasons for caution: Three main factors might limit the robustness of our work: the textual corpus analyzed is based on abstract and titles, the reproducibility of the stochastic algorithms applied, which may produce slightly differing results at each run, and the interpretation of the topics obtained. Wider implications of the findings: This study should prove beneficial in the design of research strategies and policies that foster the alignment between supply (assisted reproduction research) and demand (society). Study funding/competing interest(s): PTQ-14-06718 of the Spanish MINECO Torres Quevedo programme (FAM).