PURPOSE: to determine the values of perineal muscular force (PMF) in the lying and seated positions and to identify the values of PMF between first pregnancy, according to type and the characteristics of the vaginal delivery and cesarean section. METHODS: study of the transversal type, performed in a maternity of Brazilian Public the Health System (SUS) in the city of São Paulo. The sample consisted of 95 primiparae at term. Evaluation occurred between the 40th and 45 th, day with an interview, physical examination and measurement of PMF using a perineometer of the Kegel type. The measurement was carried out in the lying and seated positions, muscular status (at rest and in maximum contraction), and the average of three measures for each position and muscular state were considered. RESULTS: 76.8% (73) of the women had vaginal delivery and 23.2% (22) cesarean section. After vaginal delivery, intact perineum in 18.9%, (18), perineal rupture in 24.2% (23), and episiotomy in 33.7% (32) were observed. Obtained values of the PMF were: lying position muscular rest 18. 9 mmHg, lying position maximum contraction: 30,7 mmHg, seated position muscular rest: 34.5 mmHg, seated positions maximum muscular contraction: 46.5 mmHg. CONCLUSION: there was association between the type and the characteristics of the delivery and PMF.
Parturition; Natural childbirth; Pelvic floor; Perineum
