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

BackgroundPhysical 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. ObjectivesTo 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 SourcesPubMed and Web of Science. MethodsTwo independent reviewers systematically examined the articles in each database. The information from the included articles was summarized by a single researcher. ResultsA 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 maternal and neonatal health-related outcomes (n=16). ConclusionPF during pregnancy has been assessed through a wide variety of protocols, mostly lacking validity and reliability data. PROSPERO Registration Number: CRD42018117554 Key pointsO_LIPhysical Fitness during pregnancy has been assessed through a wide variety of tests (n=191) and different protocols (n=149). C_LIO_LIWe found that cardiorespiratory fitness has been assessed with 75 different protocols (many of them made ad hoc), muscular fitness with 16 different protocols, flexibility with 13 different protocols, and balance with 40 different protocols. C_LIO_LIMost of the protocols lacked validity and reliability data, which limits the confidence on the association of fitness with maternal and neonatal health-related outcomes, which is still scarce. C_LIO_LIWe advocate for an expert consensus to be developed in the following years to achieve the goal of appropriate and effective PF assessment during pregnancy. C_LI Running HeadingAssessing physical fitness during pregnancy: validity, reliability and relationship with maternal and neonatal health-related outcomes.