Does pregnancy affect pelvic organ mobility?

BACKGROUND: It is generally accepted that parity is a strong predictor of pelvic organ prolapse and incontinence. However, controversy persists as to whether this effect is due to pregnancy itself or parturition. AIMS: To define the contribution of early and late pregnancy to bladder mobility.
METHODS: Case control series, using 88 non-pregnant control subjects recruited for a heritability study on urinary incontinence and prolapse, matched for age and ethnicity with 28 pregnant women seen at 10-17 weeks and again at 32-39 weeks' gestation. Main outcome parameters were ultrasound measures of anterior, central and posterior compartment descent as well as joint mobility measurements.
RESULTS: Patients in early pregnancy showed higher values for bladder mobility in comparison with non-pregnant controls, although this did not reach significance for all parameters. However, when late pregnancy data were tested against non-pregnant controls, this difference reached significance for all tested parameters. Uterine and rectal descent did not show any significant differences between groups. Results for joint mobility were inconsistent.
CONCLUSIONS: This study supports the hypothesis that bladder and urethral mobility increase in pregnancy. This effect is already noticeable at 6-18 weeks. As similar changes are also seen in elbow hyperextension, a generalised effect on connective tissue biomechanics, likely hormonal, can be hypothesised.