Presenting information in papers allows readers to see the evidence for the research claims. The amount of information presented to readers is increasing in high impact factor scientific journals. The aim of the present study was to determine whether there was a similar expansion in the amount of information presented to readers in subject-specific journals. We examined 878 research papers that were published in the journals Biology of Reproduction and Reproduction during the first six months of 1989, 1999, 2009, and 2019. Although there were few differences between the journals, we found that between 1989 and 2019 the number of figures increased 1.5-fold, the number of figure panels increased 3.6-fold, and the number of display items increased 5.6-fold. Amongst the display items, the number of images per paper increased 10-fold, and the number of graphs per paper increased 3.7-fold. The median paper in 1989 was 8 pages long, contained 6 tables and/or figures, with 1 image and 4 graphs. In 2019 the median paper was 12 pages long, contained 7 tables and/or figures, with 13 images and 15 graphs. This expansion of information in subject-specific journals implies that authors, reviewers, and editors need to help readers digest complex biological messages without causing information overload.Lay summaryWe are living in an age of science and information. The amount of information presented in research papers has increased over time in the top science journals. Our research examined whether there has been a similar expansion in information in two influential subject-specific journals. We counted how much information was presented in 878 research papers across a 30-year period in the journals Biology of Reproduction and Reproduction. There were few differences between the two journals. But there was a striking increase in the information presented to readers in 2019 compared with 1989. The typical paper in 1989 was 8 pages long and contained 1 picture and 4 graphs. In 2019 the typical paper was 12 pages long and contained 13 pictures and 15 graphs. This expansion of information means that subject-specific journals must balance the presentation of complex biological messages with the risk of causing information overload.