Acute vaso-occlusive pain is temporally associated with the onset of menstruation in women with sickle cell disease

Background: Acute vaso-occlusive pain episodes in sickle cell disease (SCD) are associated with increased rates of hospitalization and early mortality. Despite the observation that women have higher rates of acute vaso-occlusive pain episodes than men, sex-specific risk factors for acute vaso-occlusive pain have not been identified. We tested the hypothesis that acute vaso-occlusive pain is temporally associated with the onset of menstruation in women with SCD. Methods: Initially, using a cross-sectional study design, we administered questionnaires, including validated measures of SCD pain frequency and severity within the last 30 days, as well as menstrual symptoms in a discovery group (n = 103). We then confirmed our findings by administering the same questionnaires online in a replication group (n = 118). A validated questionnaire was used to define dysmenorrhea. Results: In the initial discovery group, 28% (29 of 103) reported acute vaso-occlusive pain episodes temporally associated with menstruation, and 72% (74 of 103) did not. Of the 29 reporting acute vaso-occlusive pain associated with menstruation, 90% (26) and 10% (3) did and did not meet criteria for dysmenorrhea, respectively. In the replication group, 36% (43 of 118) reported acute vaso-occlusive pain temporally associated with menstruation. Of the 43 reporting acute vaso-occlusive pain associated with menstruation, 60% (26) and 40% (17) did and did not meet criteria for dysmenorrhea, respectively. Conclusions: In both the discovery and replication groups, we demonstrate that acute vaso-occlusive pain is temporally associated with the onset of menstruation that women with SCD can distinguish from dysmenorrhea.