Is an episiotomy always necessary during an operative vaginal delivery with vacuum? A longitudinal study

Figures & data

Figure 1. Flow chart.

Table 1. Descriptive analysis of our cohort of women (n = 466).

		No episiotomy (n = 285)	Episiotomy (n = 181)	p-value
Number of patients per hospital, n (%)	Hospital 1	155 (54.4)	132 (72.9)	<.001
	Hospital 2	116 (40.7)	34 (18.8)
	Hospital 3	14 (4.9)	15 (8.3)
Age class, n (%)	18-29 years old	75 (26.5)	59 (32.7)	N.S.
	30-39 years old	184 (65.0)	105 (58.3)
	>40 years old	24 (8.5)	16 (8.9)
	Missing	2	1
Parity, n (%)	Primigravidae	217 (76.1)	165 (91.2)	<.001
	Multiparous	68 (23.9)	16 (8.8)
Maternal BMI, n (%)	<18.5	9 (3.2)	4 (2.2)	N.S.
	<25.0	94 (33.0)	57 (31.5)
	<30.0	114 (40.0)	74 (40.9)
	≥30	68 (23.8)	46 (25.4)
Maternal ethnicity, n (%)	Caucasian	234 (82.1)	148 (81.8)	N.S.
	Hispanic	9 (3.2)	7 (3.9)
	Afro-American	25 (8.8)	15 (8.3)
	Asian	17 (5.9)	11 (6.0)
Previous Cesarean Section, n (%)	0	273 (95.8)	172 (95.0)	N.S.
	1	12 (4.2)	9 (5.0)
	2	0	0
	>2	0	0
Tears, n (%)	No tear / grade I	186 (65.2)	−	<.001
	Grade II	82 (28.8)	178 (98.3)
	Grade III / IV	17 (6.0)	3 (1.7)
Labor, n (%)	Spontaneous	200 (70.2)	117 (64.6)	N.S.
	Induced	85 (29.8)	64 (35.4)
Indication to operative delivery, n (%)	CTG category II	155 (54.4)	87 (48.1)	.024
	CTG category III	9 (3.1)	2 (1.1)
	Abnormal labor progression	62 (21.8)	61 (33.7)
	Exhausting during labor	56 (19.7)	27 (14.9)
	Elective shortening stage II of labor	3 (1.0)	4 (2.2)
Transition, n (%)	No	192 (67.4)	131 (72.4)	N.S.
	Yes	93 (32.6)	50 (27.6)
Epidural analgesia, n (%)	No	143 (50.2)	94 (51.9)	N.S.
	Yes	142 (49.8)	87 (48.1)
Fetal birthweight, mean (±SD)	–	3,328 (409)	3,371 (429)	N.S.
Fetal birthweight, n (%)	<2500 gr	16 (5.6)	8 (4.5)	N.S.
	<4000 gr	257 (90.2)	157 (86.7)
	>4000 gr	12 (4.2)	16 (8.8)
Fetal presentation, n (%)	Occiput Anterior	231 (85.6)	141 (82.5)	N.S.
	Occiput Posterior	29 (10.7)	22 (12.8)
	Occiput Temporal	10 (3.7)	8 (4.7)
	Missing	15	10
Fundal pressure, n (%)	No	117 (42.5)	51 (28.3)	.002
	Yes	158 (57.5)	129 (71.7)
	Missing	10	1
Number of contractions, n (%)	Zero	35 (12.3)	8 (4.4)	N.S.
	One	115 (40.4)	62 (34.3)
	Two	93 (32.6)	75 (41.4)
	Three	34 (11.9)	23 (12.7)
	More than four	8 (2.8)	13 (7.2)
CTG interpretation, n (%)	Proper interpretation	71 (32.3)	53 (35.6)	N.S.
	Not proper interpretation	81 (36.8)	53 (35.6)
	CTG not readable	68 (30.9)	43 (29.8)
	Missing	65	32
Expulsive phase duration, n (%)	< 1 h	86 (30.2)	54 (29.8)	N.S.
	1-2 h	147 (51.6)	84 (46.4)
	> 2 h	52 (18.2)	43 (23.8)

Table 2. Regression models for the risk of OASIs.

OASIs vs not
	All women (n = 466)			Just primigravidae (n = 382)
	Odds Ratio	95% CI	p-value	Odds Ratio	95% CI	p-value
Episiotomy vs not	0.25	0.07–0.88	0.031	0.26	0.07–0.92	0.037
Expulsive phase < 1h vs 1-2h	0.18	0.05–0.69	0.012	0.23	0.06–0.87	0.030
Expulsive phase > 2h vs 1-2h	0.55	0.17–1.81	0.325	0.59	0.18–1.96	0.388
Multiparous vs primigravida	0.35	0.04–2.87	0.330	−	−	−
Fundal pressure, yes vs not	1.55	0.53–4.54	0.428	1.40	0.47–4.16	0.548

Note. Unadjusted and adjusted binary logistic regression models were performed both in the full cohort and in the Primiparous cohort to explore the risk of OASIs vs not by employing the dichotomous variable. The selection of covariates for inclusion in the models was done using a stepwise approach, gradually adding each covariate to the model and excluding nonsignificant variables at each step. This approach was used to overcome the limitation of low sample size.

Binary logistic regression: no OASIS = 0; OASIS = 1.

Data availability statement

The data that support the findings of this study are available from the corresponding author, F.F., upon reasonable request.