Research Committee Proposal

Title:  Does Pregnancy Alter the Injury Characteristics of the Chest Wall and Pelvis?


The main hormones that may affect articular cartilage in peripartum and postpartum females include estrogen, testosterone, progesterone, and relaxin.  The key hormones that may affect ligaments during pregnancy and lactation are estrogen, progesterone, testosterone, relaxin, SHBG, and IGF-1.  Unique to pregnancy, relaxin has been shown to have a role in remodeling connective tissue and reducing soft tissue tension in the pubic symphysis in preparation for parturition. In several mammalian species (humans, guinea pigs, mice), elevated levels of estrogen and relaxin aid in the transformation of the pubic symphysis hyaline cartilage into fibrocartilage and eventually into the interpubic ligament during pregnancy.  Little is known about the effects of these hormones on costal cartilage and the injury mechanics of motor vehicle injuries in pregnant females.

Previous study

This year at the CWIS meeting we presented our single center evaluation of injuries in pregnant and non-pregnant females between the ages of 18 - 45 years old.  We retrospectively evaluated patents over a 8 year period at our Level 1 trauma center.  The significant findings were:  One Thousand Six Hundred and Eighteen patients were identified with an average age (29+/-8) and ISS (5 (1-12)).  The incidence of rib/sternal fractures was significantly lower in pregnant patients (8% vs 15%, p = 0.047) and the incidence of pulmonary contusion, lung laceration, and hemopneumothorax was similar.  Pregnant and non-pregnant patients with rib/sternal fractures had similar ISS values (21 (13-27) vs 17 (11-22), p=0.363) but pregnant patients without fractures had a significantly lower ISS (1 (0-5) vs 4 (1-9), p < 0.001).

When the study was exclusively at MUSC, it not adequately powered to perform a regression analysis to determine if pregnancy was protective.


We would like to replicate this study at several centers to increase the number of pregnant patients identified to determine if pregnancy may be protective with MVC.

Aim 1:  Determine if pregnancy is protective against rib fractures

Aim 2:  Determine if pregnancy is protective against pelvic fractures

Aim 3:  Determine if these effects are seen beyond bones with large cartilaginous attachments

Study Criteria

Inclusion Criteria

  • Age: 18 - 45 year old
  • Sex: Female
  • Admitted to center and data abstracted in the Trauma Registry

Exclusion Criteria: None


Centers must verify that ALL trauma activations are entered into their trauma registry even is injuries are not present.  Centers must verify that they did not have a major change to the registry over the study period of 2010 - 2017.

If you are interested in participating, please indicate your interest online by clicking here or email

Evert A. Eriksson, MD, FACS

This effort will be led by Evert Eriksson, MD, FACS, FCCP from the CWIS Research Committee.  Dr. Eriksson is an actively practicing surgeon and trauma medical director at the Medical University of South Carolina who holds board certification in neurocritical care, critical care surgery and general surgery.  In addition, he is an Associate Professor of Surgery. His research interests include: non-obstetrical surgical emergencies, traumatic brain injury, pulmonary embolism, coagulation, endocrine response to critical illness,  ICU pharmacotherapy, thoracic trauma, and reconstruction of the chest following severe injury.