1. Full citations found in PubMed database
222 items
Full citations found in PubMed database
191 items
Total clearly not relevant citations based on the analysis of titles
31 items
Potentially relevant to abstract analysis
Articles excluded by the absence of the exercise group (n = 1)
Articles excluded by the absence of variables related to placenta morphology
  (n = 9)
Articles excluded by drug intervention group (n = 1)
Articles excluded by the use of animals
(n = 11)
9 Items
Potentially relevant to full data analysis
Articles excluded by gestational age outcome analysis
  (n = 1)
Articles excluded by the absence of placental data
  (n = 1)
Articles excluded by the absence of control group or data
(n = 2)
Articles excluded for lack of data (mean and standard deviation)
(n = 1)
4 items
Included in the systematic review and meta-analysis