Table 2.

Comparison of patient backgrounds of full-term birth and preterm birth

	Full-term birth	Preterm birth	p value
Number of patients	56	27
Gestational age at delivery, weeks	38.0 (37.0–39.0)	34.0 (32.0–36.0)	< 0.001
Birth weight, g	2892 (2610–3115)	2154 (1568–2400)	< 0.001
Age, years	32 (30–36)	34 (31–36)	0.249
SLE duration, years	7.5 (3.3–11.8)	9.0 (5.0–16.0)	0.056
Lupus nephritis, n (%)	8 (14.3)	14 (51.9)	< 0.001
APS, n (%)	21 (37.5)	12 (44.4)	0.634
SLEDAI, score	0 (0–4)	1 (0–4)	0.225
SLEDAI ≥ 4, n (%)	3 (5.4)	5 (18.5)	0.103
Preeclampsia, n (%)	3 (5.4)	5 (18.5)	0.106
Comorbidity
Diabetes mellitus, n (%)	5 (8.9)	6 (22.2)	0.163
Hypertension, n (%)	3 (5.4)	5 (18.5)	0.106
Past use of steroid pulse therapy, n (%)	7 (12.5)	11 (40.7)	0.009
Past use of IVCY, n (%)	6 (10.7)	5 (18.5)	0.326
Prednisolone dose, mg/day	9.0 (3.1–11.0)	10.0 (7.0–12.0)	0.181
Azathioprine, n (%)	14 (25.0)	3 (11.1)	0.245
Tacrolimus, n (%)	25 (44.6)	15 (55.6)	0.482
HCQ, n (%)	5 (8.9)	4 (14.8)	0.463
Serum C3 level, mg/dL	87.5 (75.0–96.3)	77.5 (68.2–84.8)	0.027
Positive Anti-ds-DNA Ab, n (%)	35 (62.5)	20 (74.1)	0.333
Anti-dsDNA Ab, IU/ml	5.9 (3.0–8.4)	3.0 (1.8–7.4)	0.082
Positive anti-Ro/SS-A Ab, n (%)	19 (33.9)	10 (37.0)	0.810
Positive anti-RNP Ab, n (%)	19 (33.9)	9 (33.3)	1.000
Positive anti-Sm Ab, n (%)	3 (5.4)	3 (11.1)	0.385

Data are presented as median value (interquartile range) or number of patients. The p values were estimated using Fisher’s exact test or Wilcoxon rank sum test

SLE systemic lupus erythematosus, SLEDAI SLE Disease Activity Index, APS antiphospholipid syndrome, IVCY intravenous cyclophosphamide therapy, HCQ hydroxychloroquine, C3 complement 3, Anti-dsDNA Ab anti-double-stranded DNA antibodies, anti-Ro/SS-Ab anti-Ro/SSA antibodies, anti-RNP Ab anti-RNP antibodies, anti-Sm Ab anti-Sm antibodies