Cesarean section in the second stage of labor is associated with early-term and late preterm birth in subsequent pregnancies

Figures & data

Figure 1. Study population.

Table 1. Demographics, clinical, and historical characteristics.

		After stage1 (N = 1068)	After stage 2 (N = 586)	p Value
Ethnicity				.085
Jewish	n (%)	669 (63)	341 (58)
Bedouin	n (%)	399 (37)	245 (42)
Mother age	Mean ± SD	29.4 ± 5.0	28.8 ± 4.8	.018
	Q2 [Q1–Q3]	29.2 [25.5–32.5]	28.5 [25.2–31.9]
LMS Social State Score^a	Mean ± SD	6.5 ± 5.3	6.0 ± 5.4	.044
	Q2 [Q1–Q3]	7.0 [2.0–11.0]	4.0 [0.0–11.0]
Pregnant age (weeks)	Mean ± SD	39 ± 1.85	38.8 ± 2	.011
	Q2 [Q1–Q3]	273.0 [266.0–280.0]	273.0 [266.0–280.0]
Gravidity	Mean ± SD	2.5 ± 0.9	2.5 ± 2.2	.4
	Q2 [Q1–Q3]	2.0 [2.0–3.0]	2.0 [2.0–3.0]
Parity
Primiparous	n (%)	972 (91)	550 (93.8)	.041
Multiparous	n (%)	96 (9)	36 (6)	.041
Infertility treatment	n (%)	61 (5.7)	18 (3.1)	.022
Recurrent pregnancy loss	n (%)	60 (5.6)	26 (4.4)	.4
Diabetes mellitus	n (%)	25 (2.3)	12 (2.0)	.8
Hypertension	n (%)	1 (<0.1)	0 (0)	>.9
Coagulopathy	n (%)	1 (<0.1)	1 (0.2)	>.9
Obesity	n (%)	10 (0.9)	2 (0.3)	.2

^aA multivariate analysis of the population’s demographic, social, and economic characteristics from Israel’s administrative sources.

Table 2. Pregnancy and labor information.

		After stage 1 (N = 1068)	After stage 2 (N = 586)	p Value
Gestational diabetes mellitus	n (%)	55 (5.1)	25 (4.3)	.5
Gestational hypertension	n (%)	26 (2.3)	4 (0.7)	.01
Preeclampsia	n (%)	50 (4.5)	14 (2.3)	.02
Preterm birth	n (%)	49 (4.6)	43 (7.3)	.026
Preterm PROM	n (%)	125 (12)	56 (9.6)	.2
UTI	n (%)	4 (0.4)	0 (0)	.3
Pathological presentation	n (%)	55 (5.1)	32 (5.5)	.9
CS	n (%)	722 (67.6)	367 (63.7)	.038
Elective CS	n (%)	587 (55)	299 (51)	.12
Stage 1 CS	n (%)	107 (10)	22 (3.8)	<.001
Stage 2 CS	n (%)	28 (2.6)	46 (7.9)	<.001
Cervical incompetence	n (%)	4 (0.3)	4 (0.7)	.4
Hospitalization length	Mean ± SD	5.3 ± 2.0	5.0 ± 1.9	<.001
	Q2 [Q1–Q3]	5.0 [4.0–6.0]	5.0 [4.0–5.0]
Polyhydramnios	n (%)	43 (3.8)	21 (3.5)	.65
Oligohydramnios	n (%)	21 (1.9)	8 (1.3)	.37

Note: PROM: premature rapture of the membranes; UTI: urinary tract infection; CS: cesarean section.

Table 3. Neonatal outcomes in subsequent labor.

		After stage 1 (N = 1068)	After stage 2 (N = 586)	p Value
AGA	n (%)	918 (87)	520 (90)	.1
LGA	n (%)	105 (10.0)	51 (8.8)	.45
SGA	n (%)	31 (2.9)	10 (1.7)	.13
Infant PH	Mean ± SD	7.3 ± 0.1 ,7.3 [7.3–7.4]	7.3 ± 0.1 ,7.3 [7.3–7.4]	.7
	Q2 [Q1–Q3]
Infant BE	Mean ± SD	3.9 ± 2.7	2.7 ± 2.1	.033
	Q2 [Q1–Q3]	3.2 [1.5–5.3]	2.1 [1.2–4.2]
Apgar score after 5 min	Median [Q1–Q3]	10 (9, 10)	10.00 (10, 10)	.8
Apgar score after 10 min	Median [Q1–Q3]	10 (10, 10)	10 (10, 10)	.066
Asphyxia	n (%)	0 (0)	1 (0.2)	.2
Meconium aspiration	n (%)	0 (0)	1 (0.2)	.2
Persistent hypoglycemia	n (%)	4 (0.4)	8 (1.3)	.023
Hypotonia	n (%)	71 (6.4)	31 (5.2)	.26
Neonatal death	n (%)	8 (0.7)	2 (0.3)	.8

Note: AGA: appropriate for gestational age; LGA: large for gestational age; SGA: small for gestational age.

Table 4. Multivariable logistic regression—preterm birth in the following pregnancy adjusted for confounding factors.

Variable	OR	95% CI	p Value
CS during the second stage of labor^a	1.78	1.14, 2.76	.011
Age^a	1.02	0.97, 1.07	.5
LMS Social State Score^a	1.02	0.98, 1.07	.3
Multiparous in index pregnancy	1.86	0.89, 3.59	.078
Nulliparous in index pregnancy	1.16	0.06, 5.98	.9
Infertility treatment^a	0.91	0.26, 2.37	.9
Gestational hypertension^b	1.56	0.23, 5.98	.6
Preeclampsia^b	1.96	0.65, 4.83	.2
Cesarean section^b	1.03	0.64, 1.69	>.9

Note: OR: odds ratio; CI: confidence interval.

^aIndex pregnancy.

^bThe following pregnancy.

Figure 2. Kaplan–Meier curves of preterm birth in subsequent birth by stage of delivery in previous pregnancy.