The IPA will be publishing its annual diversity statistics in April, marking the first time in five years that it has not released the data in January.
The research highlights the gender and ethnicity split among IPA member agencies.
When the IPA began compiling the data in 2015, it set a target for the industry to achieve 40% female and 15% black, Asian and minority ethnic representation in leadership roles by 2020, as well as a quarter of new starters to come from a BAME background.
Last year’s study found just marginal increases in gender and ethnic diversity in 2018, and also had the lowest response rate since the survey began.
It was also the first year that the IPA did not list agencies by name because of "data and privacy concerns".
The 2019 statistics are set to be published in April, coinciding with the IPA’s annual Census. The IPA also plans to release a Diversity 2020 report with "discussion and analysis of the figures, the targets, the bigger picture and case studies, as well as providing a roadmap for a more diverse adland of the future".
Paul Bainsfair, the IPA’s director-general, said: "There is no question that diversity and inclusivity remain very much at the forefront of the IPA’s agenda.
"We have had a healthy response from our agencies to our 2019 Census so far, but are still waiting on a few significant agencies whose numbers will affect the final results. We want to present a comprehensive report, therefore we will be bringing out our diversity figures in April 2020 to ensure we have the most accurate lie of the land regarding industry diversity levels.
"It is worth noting, however, that we will not know if the industry has hit our targets until the publication of the 2020 Census in 2021, but we are committed to helping agencies reach this target."