Case Studies in Physiology: Adaptation of load-bearing tendons during pregnancy.

Pregnancy is characterized by hormone changes that could alter musculoskeletal (MSK) properties and temporarily increase soft tissue injury risk. Although the prevalence of MSK injuries in pregnancy has not yet proven itself to be a widespread problem, indirect evidence indicates an uptake in the prevalence of strength training and vigorous-intensity activity during pregnancy, which may result in increased MSK injury incidence. Combining this evidence with the association between sex hormones and MSK injury risk, we recognize the potential importance of this research area and believe the (prospective) examination of connective tissue properties in pregnancy is appropriate. Given the dearth of information on MSK adaptations to pregnancy, we present a variety of morphological, mechanical, and functional tendon data from two consecutive pregnancies in one woman as a means of highlighting this under researched topic. These data may be representative of the general pregnant population, or it may be highly individualized. More research is required for a better understanding of MSK adaptation and injury risk during and after pregnancy. NEW & NOTEWORTHY The literature is sparse on the topic of MSK adaptation and injury risk during pregnancy, hence we present this case study as means of highlighting an area of research that is of increasing importance. Here, we present a case study concerning the morphological, mechanical, and functional adaptation of load-bearing tendons during this unique period. We also discuss different rationales, study considerations, and future directions for continuing this research theme.