Results
Overall pregnant women had a significantly straighter and more
posteriorly oriented coccyx when compared to nulliparous women. This was
reflected by a change in 3 measures at the univariate level. The
coccygeal curvature index was higher in pregnant (89.2 ± 10.0) women
relative to nulliparous (78.7 ± 6.6, p=0.003) and parous (80.0 ± 5.5,
p=0.004) women. The sacrococcygeal curvature index and sacrococcygeal
angle also increased in the pregnant as compared to the nulliparous
group (73.3 ± 5.8 versus 79.2 ± 3.7, p=0.016; 92.8° ± 10.9° versus
109.3° ± 9.4°, p=0.002, respectively) with no difference between
pregnant and parous groups for these measurements.