Is There Relationship Between the Pelvic Floor Muscles Strength and Sexual Function in Primigravid and Non-pregnant Nulliparous?

This is an observational cross-sectional study. The sample consisted of 161 women divided into two groups: the first of pregnant women, formed by 81 primigravidae participants in the Prenatal Program of the public health system in Uberlandia city (Brazil). The second consists of 80 non-pregnant nulliparous. All participants signed an informed consent and the study was approved by the Ethics Committee of the Federal University of Uberlandia (nº 145.623/2012).

To estimate the average strength of vaginal palpation and vaginal squeeze pressure in primigravid, the investigators used the following equation to scale the sample: Zα/2 refers to the probability (α/2) standard one-tailed normal distribution; σ2 is the variance associated with vaginal palpation and vaginal squeeze pressure; ε is the sampling error. Based on a similar study, which evaluated similar population, it was assumed: α=0.05, σ=1.34 and ε=0.32 for vaginal palpation; and it was assumed: α=0.05, σ=12.60 and ε=3.00 for vaginal squeeze pressure. Therefore, the sample size would be 67 and 68 women, respectively.

The PFM assessment

PFM evaluation was performed by vaginal palpation and vaginal squeeze pressure. These methods are widely used in research involving the female pelvic floor and many studies have shown its reproducibility and validity.

The same examiner conducted all evaluations and before the start of the study, the reproducibility was tested. Ten women were evaluated twice, with an interval of one week to determine the intraclass correlation coefficient (ICC) of all variables.