Maternal and neonatal risk factors for early-onset group B streptococcal disease: a case control study

Figures & data

Table 1 Maternal outcomes and their pregnancy, intrapartum, and postpartum characteristics

	Cases (n=99)	Control (n=200)	OR (95% CI)	P-value
Age (years)
Mean ± SD	28.2±7.8	28.4±5.6	NA	0.84
Weight (kg)
Mean ± SD	79.4±15.6	78.4±8.6	NA	0.48
Height (cm)
Mean ± SD	157.7±5.8	160.3±5.5	NA	<0.01
BMI (kg/m^2)
Mean ± SD	31.8±5.1	30.5±2.6	NA	0.02
Gravida
Mean ± SD	5.1±2.7	4.6±2.3	NA	0.15
Parity
Mean ± SD	3.2±3.1	3.1±2.6	NA	0.07
Number of live births
Mean ± SD	2.5±2.6	2.5±2.3	NA	0.97
Gestational age at birth
Mean ± SD	36.3±3.8	38.5±2.0	NA	<0.01
Previous baby with GBS
Yes	4 (4%)	0 (0%)	NA	0.004
ANC attendance (booking)
Yes	64 (65%)	169 (85%)	0.34 (0.19–0.61)	<0.01
Previous fetal death
Yes	9 (9%)	5 (3%)	3.97 (1.29–12.19)	0.01
GBS carrier
Yes	19 (19%)	14 (7%)	3.22 (1.54–6.74)	0.001
GBS bacteriuria
Yes	5 (5%)	1 (0.5%)	10.76 (1.24–93.42)	0.008
Intrapartum temp ≥38°
Yes	15 (15%)	5 (3%)	7.10 (2.50–20.17)	<0.01
Maximum intrapartum temperature
Mean ± SD	37.3±0.6	37.0±0.4		<0.01
RM
Yes	66 (68%)	30 (15%)	11.99 (6.74–21.36)	<0.01
Duration of RM (hours)
Mean ± SD	10.7±16	5.3±4.9		<0.01
Antibiotic in labor
Yes	45 (45%)	36 (18%)	3.92 (2.29–6.71)	<0.01
No of vaginal examinations
Mean ± SD	6.1±3.5	3.5±2.0		<0.01
Mode of delivery
NSVD	74 (75%)	172 (86%)	1.98 (1.07–3.68)	0.03
Operative	23 (23%)	27 (14%)
Maternal infection PP
Yes	15 (15%)	4 (2%)	8.92 (2.87–27.68)	<0.01
Maternal PP antibiotics
Yes	25 (25%)	28 (14%)	2.12 (1.16–3.89)	0.01

Abbreviations: ANC, antenatal care; BMI, body mass index; CI, confidence interval; GBS, group B streptococcus; NA, not applicable; NSVD, normal spontaneous vaginal delivery; OR, odds ratio; PP, postpartum; RM, ruptured membranes; SD, standard deviation.

Table 2 Characteristics and outcomes of neonatal group B streptococcal infection

	Cases (n=99)	Control (n=200)	OR (95% CI)	P-value
Sex
Male	47 (47%)	112 (56%)	1.34 (0.81–2.20)	0.25
Female	46 (46%)	82 (41%)
CTG with fetal distress
Yes	59 (60%)	45 (23%)	5.31 (3.14–8.99)	<0.01
Fetal tachycardia (>160/min)
Yes	22 (22%)	7 (4%)	8.05 (3.30–19.62)	<0.01
Fetal scalp electrode
Yes	53 (54%)	43 (22%)	4.37 (2.59–7.37)	<0.01
Fetal scalp blood sampling
Yes	12 (12%)	0 (0%)	NA	NA
Baby weight (kg)
Mean ± SD	2.9±0.7	3.2±0.5	NA	<0.01
Baby length (cm)
Mean ± SD	49.0±3.8	50.6±1.4	NA	<0.01
Days in NICU
Mean ± SD	9.7±10.3	0.3±2.4	NA	<0.01
Days in the hospital
Mean ± SD	18.0±13.8	2.1±5.3	NA	<0.01
Age at diagnosis (days)
Mean ± SD	3.1±1.4	NA	NA	NA
Respiratory distress
Yes	75 (76%)	21 (11%)	28.90 (15.00–55.69)	<0.0001
Oxygen requirement
Yes	77 (78%)	21 (11%)	32.63 (16.73–63.66)	<0.0001
CPAP
Yes	45 (45%)	4 (2%)	42.19 (14.51–122.67)	<0.0001
Assisted ventilation
Yes	36 (36%)	3 (1.5%)	38.56 (11.47–129.60)	<0.0001
Nitric oxide
Yes	12 (12%)	1 (0.5%)	27.95 (3.58–218.39)	<0.0001
Surfactant
Yes	15 (15%)	2 (1%)	18.02 (4.03–80.57)	<0.0001
Convulsions
Yes	18 (18%)	1 (0.5%)	45.11 (5.92–343.67)	<0.0001
Tube feeding
Yes	36 (36%)	3 (1.5%)	38.56 (11.47–129.60)	<0.0001
Proven sites of colonization
Sepsis
Yes	35 (35%)	1 (0.5%)		0.70
Pneumonia
Yes	20 (20%)	1 (0.5%)
Meningitis
Yes	4 (4%)	0 (0%)
Focal
Yes	37 (37%)	0 (0%)
All of the above
Yes	1 (1.0%)	0 (0%)

Abbreviations: CI, confidence interval; CPAP, continuous positive airway pressure; CTG, cardiotocogram; NICU, neonatal intensive care unit; OR, odds ratio; SD, standard deviation.

Table 3 Multiple logistic regression identifying the most important risk factors associated with the development of early-onset group B streptococcal disease

Maternal risk factors	OR	95% CI	P-value
Antenatal care provided	0.30	0.09–0.89	0.03
Ruptured membranes	9.62	3.15–29.42	0.0001
Antibiotics during labor	0.16	0.38–0.67	0.013

Abbreviations: CI, confidence interval; OR, odds ratio.