Table of Contents
ISRN Obstetrics and Gynecology
Volume 2014 (2014), Article ID 124206, 4 pages
Clinical Study

Perineal Distensibility Using Epi-no in Twin Pregnancies: Comparative Study with Singleton Pregnancies

Pelvic Floor Sector, Department of Obstetrics, Federal University of São Paulo (UNIFESP), Rua Carlos Weber, 956 Apartment 113 Visage, Vila Leopoldina, 05303-000 São Paulo, SP, Brazil

Received 18 January 2014; Accepted 9 March 2014; Published 27 March 2014

Academic Editors: M. Friedrich and E. Shalev

Copyright © 2014 Juliana Sayuri Kubotani et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The aims of this study were to compare perineal distensibility between women with twin and singleton pregnancies and to correlate these women’s perineal distensibility with anthropometric data. This prospective cross-sectional case-control study was conducted among nulliparous women, of whom 20 were pregnant with twins and 23 with a single fetus. Perineal distensibility was evaluated in the third trimester by means of Epi-no, which was introduced into the vagina and inflated up to the maximum tolerable limit. It was then withdrawn while inflated and its circumference was measured. The unpaired Student’s -test was used to compare perineal distensibility in the two groups and Pearson’s correlation coefficient ( ) was used to correlate the pregnant women’s perineal distensibility with their anthropometric data. There was no difference in perineal distensibility between the twin group (16.51 ± 2.05 cm) and singleton group (16.13 ± 1.67 cm) ( ). There was a positive correlation between perineal distensibility and abdominal circumference ( ; ). The greater the abdominal circumference was, the greater the perineal distensibility was, regardless of whether the pregnancy was twin or singleton.