Pelvic Floor Muscle Morphometry and Function in Women With Primary and Secondary Provoked Vestibulodynia

Abstract

Introduction: Provoked vestibulodynia (PVD) can be categorized as primary PVD affecting women from their first sexual intercourse or secondary PVD, which appears after a period of pain-free intercourse. There is growing evidence that these subgroups may be distinct entities presenting different pathophysiological mechanisms. Although there are documented pelvic floor muscle alterations in provoked vestibulodynia, no study has yet evaluated whether the pelvic floor muscle morphometry or function differed between women with primary and secondary provoked vestibulodynia.

Aim: To assess and compare pelvic floor muscle morphometry and function in women with primary and secondary provoked vestibulodynia.

Methods: A total of 212 women with provoked vestibulodynia (primary = 75 and secondary = 137) participated in the study after completing a gynecologic exam to confirm their diagnosis.

Main outcome measure: Pelvic floor muscle morphometry was evaluated at rest and during maximal contraction using 3D/4D transperineal ultrasound and pelvic floor muscle function (tone, strength, speed of contraction, endurance) was assessed with a dynamometric speculum.

Results: Pelvic floor muscle morphometry at rest and during contraction was not statistically different between women with primary and secondary provoked vestibulodynia (P > .327 adjusted for the duration of symptoms; P > .137 unadjusted t-tests). Regarding pelvic floor muscle function assessed with the dynamometric speculum, no differences were found in tone, strength, speed of contraction, endurance between the 2 groups (P > .144 adjusted for duration of symptoms; P > .118 unadjusted t-tests).

Clinical implications: Women with primary and secondary PVD do not differ on pelvic floor muscle morphometric or dynamometric characteristics, suggesting that physical therapy modalities should be offered to both subgroups of PVD.

Strengths & limitations: The current study used a large and mixed clinical and community sample providing more representative findings. Moreover, the analyses were adjusted for relevant variables such as duration of symptoms. Although the inclusion of nulliparous women below 45 years of age ensured the homogeneity of the sample, it may limit the external validity.

Conclusion: These findings suggest that primary and secondary subgroups of provoked vestibulodynia cannot be differentiated by morphometric or dynamometric characteristics. Pelvic floor muscles alterations in provoked vestibulodynia are therefore not influenced by the onset of the symptoms. Fontaine F, Dumoulin C, Bergeron S, et al. Pelvic floor muscle morphometry and function in women with primary and secondary provoked vestibulodynia. J Sex Med 2018;15:1149-1157.

Keywords: Dynamometer; Pain Onset; Pathophysiology; Pelvic Floor Muscles; Primary Vestibulodynia; Provoked Vestibulodynia; Secondary Vestibulodynia; Ultrasound; Vulvodynia.