Fig. 3From: Clinical trials registries are underused in the pregnancy and childbirth literature: a systematic review of the top 20 journalsTemporal trend of clinical trials registry search by systematic reviews in the top 20 pregnancy and childbirth journals. The number (left vertical axis) of systematic reviews and meta-analyses searching (blue line) and not searching (orange line) clinical trials registries between 2007 and 2015. The grey bars represent the percentage (right vertical axis) of systematic reviews and meta-analyses that searched clinical trials registries for the given yearBack to article page