2.1. Participants
The Perinatal Medical Center, Sagamino Hospital, Japan Community Health Care Organization, recruited the participants for this study, and Azabu University performed tests of the samples and analyzed the data. A total of 321 participants were recruited for the observational study between November 2015 and June 2017 and 250 for the interventional study between July 2017 and April 2019. These were 2 different sets of participants, and none of those in the RCT were included in the observational study (This was a double-blind, parallel-group comparison study wherein participants were randomly assigned to two groups receiving omega-3 fatty acids in either perilla oil or fish oil (the recruited period was 21 months for July 2017 to April 2019), and the two abovementioned groups plus a group of participants in the observational study (historical control; the recruited period was 19 months for November 2015 and June 2017) were compared (All subjects gave their informed consent for inclusion before they participated in the study. This study was approved by the Human Research Ethics Committee of Azabu University (No. 083, 102) and was registered in the University Hospital Medical Information Network (UMIN) Center Clinical Trial Registry (UMIN000027170).