Table 3.

Subgroup analysis of antidepressant use in pregnant women with depression and risk of preterm birth: results of meta-analyses.

	Antidepressant use
	No. of studies	Summary RR (95% CI)	I2,%	P*	P**
Geographic location					0.75
Europe	2	1.51 (1.20–1.91)	17.6	0.27
Northern America	3	1.28 (0.12–14.07)	0.0	0.40
Others	2	2.17 (1.05–4.52)	58.8	0.12
Adjustment for confounders
Maternal age					0.99
Yes	4	1.62 (1.20–2.18)	21.1	0.28
No	3	1.64 (0.38–7.01)	29.0	0.25
Ethnicity					0.48
Yes	2	1.89 (1.09–3.28)	0.0	0.55
No	5	1.78 (0.94–3.39)	26.8	0.24
Maternal education					0.32
Yes	3	1.46 (1.32–1.62)	0.0	0.54
No	4	2.42 (0.78–7.49)	27.2	0.25
Tobacco use					0.99
Yes	4	1.62 (1.20–2.18)	21.1	0.28
No	3	1.64 (0.38–7.01)	29.0	0.25
Alcohol drinking					0.16
Yes	2	2.50 (1.32–4.73)	2.3	0.31
No	5	1.45 (1.31–1.61)	0.0	0.58
Pregnancy BMI					0.54
Yes	2	1.51 (1.20–1.91)	17.6	0.27
No	5	2.00 (0.94–4.28)	15.3	0.32
Parity					0.32
Yes	3	1.46 (1.32–1.62)	0.0	0.54
No	4	2.42 (0.78–7.49)	27.2	0.25

BMI, body mass index; CI, confidence interval; RR, relative risk.

*P for heterogeneity within each subgroup.

**P for heterogeneity between subgroups with meta-regression analysis.