Impact of electronic and blended learning programs for manual perineal support on incidence of obstetric anal sphincter injuries: a prospective interventional study

Table 3 Clinical characteristics and perineal status among primiparous women during the three study phases

Characteristics	Phase-1 (N = 195)	P¹	Phase-2 (N = 279)	P²	Phase-3 (N = 256)	P³
Age (years)	23 ± 4.0	0.040	24 ± 5.0	0.328	23 ± 5.0	0.306
Gestational age (weeks)	39 ± 1.5	0.333	39 ± 1.6	0.099	39 ± 2.0	0.022
BMI⁴
< 18.5	–		–		–
18.5–24.99	46 (23.6)	0.543	67 (24.0)	0.171	49 (19.1)	0.471
25–29.99	99 (50.8)		131 (47.0)		141 (55.1)
≥ 30	45 (23.1)		77 (27.6)		64 (25.0)
Missing	5 (2.6)		4 (1.4)		2 (0.8)
Method of vaginal birth
Spontaneous	184 (94.4)	0.166	253 (90.7)	0.146	241 (94.1)	> 0.999
Vacuum	11 (5.6)	0.166	26 (9.3)	0.146	15 (5.9)	> 0.999
Fetal presentation
Cephalic	193 (99.0)	> 0.999	277 (99.3)	0.433	252 (98.4)	0.703
Breech	1 (0.5)	> 0.999	2 (0.7)	0.433	4 (1.6)	0.395
Occiput posterior	1 (0.5)	0.411	–	0.433	–	0.432
Onset of labor
Spontaneous	161 (82.6)	0.447	222 (79.6)	0.040	221 (86.3)	0.292
Induced	34 (17.4)	0.447	57 (20.4)	0.040	35 (13.7)	0.292
Second stage duration (minutes)
< 30	104 (53.3)	< 0.001	94 (33.7)	0.174	105 (41.0)	0.009
30–59	62 (31.8)		78 (28.0)		81 (31.6)
≥ 60	22 (11.3)		72 (25.8)		53 (20.7)
Missing	7 (3.6)		35 (12.5)		17 (6.6)
Birthweight (grams)
< 3000	53 (27.2)	0.317	93 (33.3)	0.161	84 (32.8)	0.102
3000–4399	85 (43.6)		118 (42.3)		121 (47.3)
3500–3999	47 (24.1)		51 (18.3)		45 (17.6)
≥ 4000	10 (5.1)		17 (6.1)		6 (2.3)
Intact Perineum	35 (18.0)	0.057	71 (25.4)	0.023	89 (34.8)	< 0.001
Episiotomy	126 (64.6)	0.011	147 (52.7)	0.002	101 (39.5)	< 0.001
First degree tear	17 (8.7)	0.751	27 (9.7)	0.334	32 (12.5)	0.224
Second degree tear	31 (15.9)	0.396	53 (19.0)	0.018	71 (27.7)	0.003
OASIS⁵	31 (15.9)	0.346	35 (12.5)	0.028	17 (6.6)	0.002

• Differences were assessed for each pair of the study phases
• Categorical data were presented by n/N (%), and continuous variables by mean ± SD
• Differences were assessed by independent t-test for continuous variables and Pearson- Pearson-χ² test or Fisher’s Exact test (for cells with counts< 5) for categorical variables.
• P¹; difference between phase-1 and phase-2, P²; difference between phase-2 and phase-3, P³; difference between phase-1 and phase-3.
• BMI⁴; body mass index = maternal weight in kilograms/(height in meters)²
• OASIS⁵; obstetric anal sphincter injuries.

ISSN: 1472-6920