Gas within the endometrial cavity at postpartum US: a normal finding after spontaneous vaginal delivery

In the puerperium, the detection of gas within the endometrial cavity at ultrasound (US) has been commonly taken to indicate endometritis. Of 70 clinically healthy women in whom US was performed after uncomplicated spontaneous vaginal delivery, 13 (19%) had evidence of gas in the endometrial cavity within the first 3 postpartum days (mean, 37 hours; range, 25-59 hours) and five (7%) had such evidence in the 3rd week after delivery (mean, 2.4 weeks; range, 2.1-2.9 weeks). Gas was seen in the endometrial cavity on at least one occasion during the first 3 postpartum weeks in 15 (21%) of these apparently healthy women; in no case did clinical evidence of endometritis develop. From these observations, the authors believe that gas detected within the endometrial cavity is not, in and of itself, suggestive of endometritis, and that such a finding should be considered normal, at least until the end of the 3rd postpartum week.