Table 3.

Risk factors of preterm birth

	Odds ratio	95%CI	p value
Age at pregnancy (per unit)	1.134	0.977–1.328	0.086
History of lupus nephritis	6.267	1.750–22.443	0.005
Low serum complement 3 (< 85 IU/ml)	4.754	1.373–16.461	0.014
Past use of steroid pulse therapy	2.640	0.708–9.845	0.148

A multivariate logistic regression model. A p value of < 0.05 was considered significant