Table 3.

Risk factors present in pregnant women.

Risk factors	Combined	Effect	Combined	95% CI		Publication	Sensitivity
	quantity	model	OR value			bias	analysis
				Lower limit	Upper limit
BMI >27	6	Random	1.32	0.92	1.89	No	Consistent
Age >30	6	Random	2.8	0.36	2.93	No	Consistent
PIH	8	Random	2.42	0.73	8.05	No	Consistent
Gestational diabetes mellitus	9	Random	3.61	2.02	6.45	No	Consistent
Pre-pregnancy and mid-pregnancy smoking	8	Random	4.85	1.98	11.9	No	Consistent
Taking drugs	10	Random	2.39	1.25	4.57	No	Consistent
Unipara	5	Random	1.16	1.09	1.23	No	Consistent