Neonatal morbidity associated with maternal Group B Streptococcal colonization in individuals undergoing planned cesarean delivery

Figures & data

Figure 1. Study cohort selection from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Cesarean Registry.

Table 1. Maternal demographics and delivery characteristics of individuals undergoing cesarean without labor in the MFMU Cesarean Registry by GBS status (N = 4,963), 1999–2002.

	GBS unknown (N = 3,557)	GBS negative (N = 1,255)	GBS positive (N = 151)	p value
Maternal age (years), mean ± SD	28.4 ± 5.5	27.1 ± 5.4	29.8 ± 5.7	<.001
Race/ethnicity				<.001
Black	627 (17.6)	296 (23.6)	61 (40.4)
White	292 (8.2)	84 (6.7)	28 (18.5)
Hispanic	2,515 (70.7)	853 (68.0)	57 (37.8)
Other	123 (3.4)	22 (1.8)	5 (3.4)
Married	1,942 (54.6)	530 (42.2)	75 (49.7)	<.001
Tobacco use in pregnancy	194 (5.5)	102 (8.1)	14 (9.3)	.001
BMI at delivery (kg/m^2) (mean ± SD)	33.6 ± 6.3	34.4 ± 7.1	35.5 ± 7.6	<.001
BMI ≥ 40 kg/m^2	460 (14.0)	204 (17.7)	34 (23.9)	<.001
Maternal medical disease*	579 (16.3)	201 (16.0)	45 (29.8)	<.001
Gestational age at delivery (weeks) (mean ± SD)	39.4 ± 1.1	39.3 ± 1.0	39.1 ± 1.1	.02
Neonatal birth weight (g) (mean ± SD)	3,469 ± 512	3,455 ± 496	3,487 ± 572	.60
Male infant	1,778 (50.0)	621 (49.5)	82 (54.3)	.53
Number of prior CS				<.001
0	255 (7.2)	87 (6.9)	25 (16.6)
1	2,060 (57.9)	731 (58.3)	86 (57.0)
2	1,242 (34.9)	437 (34.8)	40 (26.5)
Antibiotic prophylaxis**				<.001
GBS	50 (1.5)	23 (2.0)	84 (60.9)
Surgical	3,211 (98.7)	1,182 (98.4)	112 (81.2)

Data are n (%) unless otherwise specified. Bold font indicates statistical significance (p < .05).

GBS: Group B Streptococcal; BMI: body mass index; SD: standard deviation; CS: cesarean section.

*Maternal medical disease includes: asthma, diabetes, chronic hypertension, seizure disorder, thyroid disease, renal disease, or connective tissue disorder.

**Coded as antibiotic administration for GBS prophylaxis or surgical prophylaxis.

Table 2. Neonatal outcomes among individuals undergoing cesarean delivery without labor and intact membranes* in the MFMU Cesarean Registry (n = 4,963).

	GBS unknown (N = 3,557)	GBS negative (N = 1,255)	GBS positive (N = 151)	p-value
Composite outcome**	208 (5.9)	75 (6.0)	6 (4.0)	.61
Clinically suspected sepsis	174 (4.9)	60 (4.8)	5 (3.3)	.67
Culture-proven sepsis	15 (0.4)	0 (0.0)	1 (0.7)	.06
Hypotension requiring treatment	2 (0.1)	4 (0.3)	1 (0.7)	.02
Ventilator support in first 24 hrs	33 (0.9)	7 (0.6)	2 (1.3)	.38
RDS	38 (1.1)	9 (0.7)	2 (1.3)	.51
Intubation	9 (0.30)	5 (0.4)	0 (0)	.57
NEC	2 (0.05)	1 (0.1)	0 (0)	>.99
HIE	2 (0.05)	1 (0.1)	0 (0)	>.99
Perinatal death	1 (0.03)	0 (0.0)	0 (0)	>.99
Base excess >12	109 (3.4)	36 (3.0)	1 (1.0)	.45
Oxygen support without ventilation	124 (3.5)	33 (2.6)	7 (4.6)	.22
TTN	133 (3.7)	45 (3.6)	5 (3.3)	.94
5-minute Apgar <7	20 (0.6)	9 (0.7)	1 (0.7)	.83
NICU admission	317 (8.9)	102 (8.1)	14 (9.3)	.68
NICU duration, (mean ± SD)	9.2 ± 24.2	8.1 ± 10.9	9.7 ± 14.2	.89

Data are n (%) unless otherwise specified.

GBS: Group B Streptococcal; RDS: respiratory distress syndrome; NEC: necrotizing enterocolitis; HIEL: hypoxic ischemic encephalopathy; TTN: transient tachypnea of the newborn; NICU: neonatal intensive care unit; SD: standard deviation.

*Individuals without labor were defined by the following: cervical dilation ≤3cm, intact membranes, and no evidence of labor or induction.

**Composite outcome includes any of the following: clinical or culture-proven sepsis, ventilator support in first 24 h, RDS, hypotension requiring treatment, intubation, NEC, HIE, or perinatal death.

Table 3. Multivariable regression model for composite severe neonatal morbidity by GBS status among individuals undergoing cesarean delivery without evidence of labor* in the MFMU Cesarean Registry (n = 4717).

	Crude RR (95% CI)	Adjusted RR (95% CI)***	p-Value for adjusted RR
Composite severe neonatal morbidity**
GBS neg (ref)	–	–	–
GBS positive	0.66 (0.29–1.50)	0.64 (0.28–1.40)	.28
GBS unknown	0.98 (0.75–1.27)	0.95 (0.73–1.22)	.67

RR: risk ratio; CI: confidence interval.

*Individuals without labor were defined by the following: cervical dilation ≤3cm and no evidence of labor or induction.

**Composite outcome includes any of the following: clinical or culture-proven sepsis, ventilator support in first 24 h, RDS, hypotension requiring treatment, intubation, NEC, HIE, or perinatal death.

***Adjusted for male sex and intrapartum antibiotic use.

Table 4. Neonatal outcomes among individuals undergoing cesarean delivery without evidence of labor* with ruptured membranes in the MFMU Cesarean Registry (n = 5,586).

	GBS unknown (N = 3,988)	GBS negative (N = 1,410)	GBS positive (N = 188)	p-Value
Composite outcome**	229 (5.7)	82 (5.8)	9 (4.8)	.85
Clinically suspected sepsis	190 (4.8)	66 (4.7)	8 (4.3)	.94
Culture-proven sepsis	16 (0.4)	0 (0.0)	1 (0.6)	.05
Neonatal death	1 (0.0)	1 (0.1)	0 (0.0)	.49
Perinatal death	1 (0.0)	1 (0.1)	0 (0.0)	.49
Hypotension requiring treatment	3 (0.1)	4 (0.3)	1 (0.5)	.07
5-minute Apgar <7	25 (0.6)	10 (0.7)	1 (0.5)	.93
Base excess >12	109 (3.4)	36 (3.0)	1 (1.0)	.45
NEC	2 (0.1)	1 (0.1)	0 (0.0)	>.99
HIE	2 (0.1)	1 (0.1)	0 (0.0)	>.99
Chest compressions	4 (0.1)	0 (0.0)	0 (0.0)	.63
Intubation	9 (0.2)	5 (0.4)	0 (0.0)	.55
Oxygen support without ventilation	136 (3.4)	38 (2.7)	9 (4.8)	.21
Ventilator support in first 24 hrs	36 (0.9)	8 (0.6)	2 (1.1)	.46
TTN	147 (3.7)	53 (3.8)	8 (4.3)	.92
RDS	45 (1.1)	10 (0.7)	3 (1.6)	.31
NICU admission	347 (8.7)	112 (7.9)	18 (9.6)	.60
NICU duration (days, mean ± SD)	7.2 ± 7.5	7.8 ± 10.9	4.9 ± 2.7	.38

Data are n(%) unless otherwise specified. Bold font indicates statistical significance (p < 0.05).

RDS: respiratory distress syndrome; NEC: necrotizing enterocolitis; HIE: hypoxic ischemic encephalopathy; TTN: transient tachypnea of the newborn; NICU: neonatal intensive care unit; SD: standard deviation.

*Individuals without labor were defined by the following: cervical dilation ≤3cm and no evidence of labor or induction.

**Composite outcome includes any of the following: perinatal death, hypoxic ischemic encephalopathy, hypotension requiring treatment, intubation, ventilator support in first 24 h, clinical or culture-proven sepsis, necrotizing enterocolitis, or respiratory distress syndrome.