I applaud the work that Clark et al are doing and sharing to decrease maternal mortality. Their approach will hopefully make pregnancy and delivery safer for more and more women. Although I am enthusiastic about their work, if I review their article in a scientific fashion, I have concerns about their conclusions.

I do not believe that the authors’ conclusions can be made using their study design. In their investigation of fatal postcesarean pulmonary embolism, the authors only looked at mortality data and not total postcesarean pulmonary embolism incidence data. I can think of other explanations that can account for the decrease in deaths from postcesarean pulmonary emboli. One possible explanation is an improved awareness of the risk of postcesarean pulmonary embolism and thus earlier diagnosis and earlier initiation of treatment. Another possibility is the use of improved and/or more aggressive treatment regimens for patients with postcesarean pulmonary emboli. To state that the policy of universal use of pneumatic compression devices “resulted in” or “reduced dramatically” fatal postcesarean pulmonary emboli is overreaching. A more appropriate conclusion would be that the authors’ protocol is correlated with a decrease in fatal postcesarean pulmonary embolism.

I endorse the use of venous thromboembolic prophylaxis for women undergoing cesarean delivery. Currently, I do not know what the optimal prophylaxis strategy is. I am concerned that premature conclusions about the efficacy of any strategy may blunt our advancement in the safe care of women.