Assessing physical fitness during pregnancy: validity and reliability of fitness tests, and relationship with maternal and neonatal health-related outcomes. A systematic review

Background: Physical fitness (PF) is a powerful marker of health throughout the lifespan. In pregnant women, higher PF is associated with better maternal and fetal health, better delivery outcomes and earlier postpartum recovery. The assessment of PF during pregnancy requires special considerations to preserve fetal and maternal health; thus, providing a compilation of the most frequently used fitness tests, and assessing their validity, reliability, and association with maternal and neonatal health-related outcomes is of scientific and clinical interest. Objectives: To systematically review studies evaluating one or more components of PF in pregnant women, to answer two research questions: 1) What fitness tests have been previously employed in pregnant women? and 2) What is the validity and reliability of these tests and their relationship with health-related outcomes? Data Sources: PubMed and Web of Science. Methods: Two independent reviewers systematically examined the articles in each database. The information from the included articles was summarized by a single researcher. Results: A total of 149 articles containing a sum of 191 fitness tests were included. Among the 191 fitness tests, 99 (i.e.,52%) assessed cardiorespiratory fitness through 75 different protocols, 28 (15%) assessed muscular fitness through 16 different protocols, 14 (7%) assessed flexibility through 13 different protocols, 45 (24%) assessed balance through 40 different protocols, 2 assessed speed with the same protocol and 3 were multidimensional tests using one protocol. A total of 19 articles with 23 tests (13%) assessed either validity (n=4), reliability (n=6), or the relationship of PF with health-related outcomes (n=16). Conclusion: PF during pregnancy has been assessed through a wide variety of protocols, mostly lacking validity and reliability data.