Table 1 Population characteristics.

Maternal age (years)

35.26 (±4.68)

Secondiparous women

45.4% (171/377)*

BMI before pregnancy (Kg/m²)

22.04 (±3.74)

Weight gain during pregnancy (Kg)

13.19 (±4.45)

Actual BMI (Kg/m²)

22.05 (±3.76)

Previous surgery

39.5% (148/375)*

N° of previous surgical interventions

0 (0 - 5)**

Previous cesarean section

4.0% (15/373)*

Number of previous cesarean sections

1 (1 - 2)**

Tobacco smoke

19.6% (73/373)*

Constipation

19.3% (72/373)*

Labour and delivery characteristics

Gestational age at birth (weeks)

39.68 (±1.34)

First labour stage (min)

256.05 (±222.08)

Second labour stage (min)

38.21 (±33.38)

Epidural analgesia

18.2% (58/319)*

Spontaneous delivery

83.8% (316/377)*

Operative delivery

16.2% (61/377)*

Intact perineum

6.6% (25/377)*

First degree vagino-perineal tears

20.4% (77/377)*

Second degree vagino-perineal tears

15.9% (60/377)*

Third-fourth degree vagino-perineal tears

1.3% (5/377)*

Episiotomy

59.4% (224/377)*

Neonatal weight (g)

3364 (±419)

Neonatal lenght (cm)

50.95 (±2.27)