Pelvic pain during pregnancy is associated with asymmetric laxity of the sacroiliac joints

Objective. The aim of this study was to investigate the association between pregnancy-related pelvic pain (PRPP) and sacroiliac joint (SIJ) laxity. Methods. A cross-sectional analysis was performed in a group of 163 women, 73 with moderate or severe (PRPP+) and 90 with no or mild (PRPP-) PRPP at 3 6 weeks of pregnancy. SIJ laxity was measured by means of Doppler imaging o f vibrations in threshold units (TU). Pain, clinical signs and disability w ere assessed with visual analog scale (VAS), posterior pelvic pain provocat ion (PPPP) test, active straight leg raise (ASLR) test, and Quebec back pai n disability scale (QBPDS), respectively. Results. Mean SIJ laxity in the PRPP+ group was not significantly different from the PRPP-group (3.0 versus 3.4 TU). The mean left-right difference, h owever, was significantly higher in the PRPP+ group (2.2 TU) than in the PR PP- group (0.9 TU). In the PRPP- group, only 4% had asymmetric laxity of th e SIJs in contrast to 37% of the PRPP+ group. Between the PRPP+ subjects wi th asymmetric and symmetric laxity of the SIJs significant differences were found with respect to mean VAS for pain (7.9 versus 7.0), positive PPPP te st (59% versus 35%), positive ASLR test (85 versus 41%) and mean QBPDS scor e (61 versus 50). Conclusions. Increased SIJ laxity is not associated with PRPP In fact, preg nant women with moderate or severe pelvic pain have the same laxity in the SIJs as pregnant women with no or mild pain. However, a clear relation betw een asymmetric laxity of the SIJs and PRPP is found.