Systematic search of PubMed, Scopus, Web of Science and Cochrane CENTRAL databases were performed based on the predefined protocol. The PRISMA statement was used for reporting the present study.

Primary searches resulted in 2132 studies. Excluding unrelated studies, finally 43 studies were found to meet our inclusion criteria. Rats, mice and guinea pigs were used in 28, 14 and 1 studies, respectively. Most of the studies evaluated hippocampus or prefrontal cortex, used prenatal restraint stress paradigm and investigated the changes only in male offspring. Most of the experiments induced stress almost during the third trimester of pregnancy. Decreased or unchanged BDNF total mRNA and BDNF mature protein, with hypermethylation in the coding exons following PNS were the most reported findings. Day of the sacrifice varied significantly between the studies.