Does delaying ureteral stent placement lead to higher rates of preoperative acute pyelonephritis during pregnancy?

Table 1 Patient characteristics associated with early and delayed time to ureteral stent placement

Demographic data/clinical parameters	Total (n = 100)	Early TTU (n = 42)	Delayed TTU (n = 58)	P value
Age (yr), mean ± SD	30 ± 4.55	31 ± 4.87	29 ± 4.19	0.06
BMI (kg/cm2), mean ± SD	23.05 ± 3.06	23.38 ±3.28	22.81 ± 2.89	0.36
Gestation (wk), mean ± SD	22 (18, 27)	22 ± 7.83	22 ± 5.02	0.99
History of stones, n (%)	26 (76)	14 (53.8)	12 (46.2)	0.16
WBC count (× 109/L), mean ± SD	13.48 ± 3.49	14.19 ± 4.12	12.97 ± 2.87	0.10
CRP (mg/dL), median (Q1, Q3)	2.64 (1.04, 4.35)	4.25 (1.9, 5.89)	1.77 (0.98, 4.0)	0.12
Stone size (mm), median (Q1, Q3)	8.25 (4.28, 14)	9.98 (4.5, 12)	9.07 (0, 15)	0.59
< 10 mm, n (%)	55 (55)	21 (38.2)	34 (61.8)	0.39
≥ 10 mm, n (%)	45 (45)	21 (46.7)	24 (53.3)
Hydronephrosis (mm), median (Q1, Q3)	26.5 (15, 62)	47 (15, 80)	34 (15, 42)	0.30
None/light, n (%)	62 (62)	21 (40.4)	31 (59.6)	0.73
Moderate/severe, n (%)	38 (38)	21 (43.8)	27 (56.3)
Stone location, n (%)				0.09
None	24 (24)	11 (45.8)	13 (54.2)
Ureter	48 (48)	24 (50)	24 (50)
Kidney	28 (28)	7 (25)	21 (75)
Urology consultation time (h), median (Q1, Q3)	27 (19, 52)	19 (13, 23)	48 (24, 90)	0.001
≤ 24 h, n (%)	53 (53)	34 (64.2)	19 (35.8)	0.00
> 24 h, n (%)	47 (47)	8 (17)	39 (83)
Preoperative fetal complications, n (%)	12 (12)	6 (50)	6 (50)	0.55
PANP, n (%)	32 (32)	15 (46.9)	17 (53.1)	0.50
UTI after surgery, n (%)	22 (22)	11 (50)	11 (50)	0.39
LOS (d), mean ± SD	7 ± 3.56	6 ± 3.03	8 ± 3.60	0.001
Total cost (Yuan in RMB), mean ± SD	12382.79 ± 5665.26	10448.95 ± 2412.28	13783.16 ± 6841.61	0.001
Newborn weight (g), mean ± SD	2893.30 ± 542.10	2891.67 ± 509.18	2894.48 ± 569.15	0.98
Cesarean section rate, n (%)	38 (38)	17 (44.7)	21 (55.3)	0.66
Preterm delivery, n (%)	8 (8)	6 (75)	2 (25)	0.07

TTU: Time to ureteral stent placement; PANP: Preoperation acute pyelonephritis; UTI: Urinary tract infection; LOS: Length of stay.