Association between sexual intercourse frequency and pelvic floor muscle morphology in pregnant women

No studies have been performed to examine the association of sexual activity and pelvic floor muscle (PFM) morphology or function during pregnancy. The aim of this study was to survey the frequency of sexual intercourse and examine the associations between the frequency of sexual intercourse and the PFM morphology in pregnant women of mainland China. The relationship between sexual intercourse frequency and stress urinary incontinence (SUI)-related symptoms was also evaluated.

Pregnant women in their first or second trimester were enrolled from January 2017 and November 2017. The morphology of the PFM was examined by transperineal ultrasound, and SUI-related symptoms were assessed by the International Consultation of Incontinence Questionnaire-Short Form (ICIQ-SF). Multivariable regression analyses were used to estimate coefficients [95% confidence intervals (CI)] with adjustment for the possible effects of cofounders.

In total, 323 pregnant women (mean age, 29.66 ± 4.32 years) were included in the analysis. Almost 49% of the women had no sexual intercourse during pregnancy. Compared with pregnant women who had no sexual intercourse, those who had sexual intercourse more than once a month had stronger LA th at rest (β = 0.59, P = 0.004 for two or three times per month; β = 0.59, P = 0.044 for weekly or more). No significant relationship was found between the frequency of sexual intercourse and any ICIQ-SF-related items.

Chinese women had inactive sexual intercourse during pregnancy. There is a slight association between increased sexual intercourse frequency and a thicker levator ani muscle in pregnant women. Future work may be directed at determining the causality of this association.