Table 4. Forest plot of antiviral intervention initiated in the second trimester compared to the third trimester with respect to maternal HBV-DNA (log10) prior to delivery (subgroups analyses according to different starting times).

Study or subgroup	Second Trimester			Third Trimester			Weight	Mean Difference	Mean Difference
	Mean	SD	Total	Mean	SD	Total		IV,Fixed,95% CI	IV,Fixed,95% CI
4.1 20 w VS 28 w
Wang et al.21 (1)	3.38	1.45	20	4.16	1.6	20	2.6%	-0.78 [-1.73, 0.17]
Wang et al.18 (1)	2.97	1.11	20	3.38	1.34	20	4.1%	-0.41 [-1.17, 0.35]
Subtotal (95% CI)			40			40	6.7%	-0.56 [-1.15, 0.04]
Heterogeneity: Chi2 = 0.36, df = 1 (P = 0.55); I2 = 0%
Test for overall effect: Z = 1.83 (P = 0.07)
4.2 20 w VS 32 w
Wang et al.21 (2)	3.38	1.45	20	5.45	1.87	20	2.2%	-2.07 [-3.11, -1.03]
Wang et al.18 (2)	2.97	1.11	20	4.83	1.63	20	3.2%	-1.86 [-2.72, -1.00]
Subtotal (95% CI)			40			40	5.4%	-1.95 [-2.61, -1.28]
Heterogeneity: Chi2 = 0.09, df = 1 (P = 0.76); I2 = 0%
Test for overall effect: Z = 5.74 (P < 0.00001)
4.3 20 w VS 36 w
Wang et al.21 (3)	3.38	1.45	20	5.98	1.67	20	2.5%	-2.60 [-3.57, -1.63]
Wang et al.18 (3)	2.97	1.11	20	5.65	1.45	20	3.7%	-2.68 [-3.48, -1.88]
Subtotal (95% CI)			40			40	6.2%	-2.65 [-3.26, -2.03]
Heterogeneity: Chi2 = 0.02, df = 1 (P = 0.90); I2 = 0%
Test for overall effect: Z = 8.41 (P < 0.00001)
4.4 24 w VS 28 w
Wang et al.21 (4)	3.68	1.42	20	4.16	1.6	20	2.7%	-0.48 [-1.42, 0.46]
Wang et al.18 (4)	3.22	1.23	20	3.38	1.34	20	3.7%	-0.16 [-0.96, 0.64]
Yin and Wang19	3.57	1.23	74	4.05	1.28	149	19.6%	-0.48 [-0.83, -0.13]
Subtotal (95% CI)			114			189	26.1%	-0.43 [-0.74, -0.13]
Heterogeneity: Chi2 = 0.53, df = 2 (P = 0.77); I2 = 0%
Test for overall effect: Z = 2.82 (P = 0.005)
4.5 24 w VS 32 w
Wang et al.21 (5)	3.68	1.42	20	5.45	1.87	20	2.2%	-1.77 [-2.80, -0.74]
Wang et al.18 (5)	3.22	1.23	20	4.83	1.63	20	3.0%	-1.61 [-2.50, -0.72]
Subtotal (95% CI)			40			40	5.2%	-1.68 [-2.35, -1.00]
Heterogeneity: Chi2 = 0.05, df = 1 (P = 0.82); I2 = 0%
Test for overall effect: Z = 4.87 (P < 0.00001)
4.6 24 w VS 36 w
Wang et al.21 (6)	3.68	1.42	20	5.98	1.67	20	2.6%	-2.30 [-3.26, -1.34]
Wang et al.18 (6)	3.22	1.23	20	5.65	1.45	20	3.4%	-2.43 [-3.26, -1.60]
Subtotal (95% CI)			40			40	6.0%	-2.37 [-3.00, -1.74]
Heterogeneity: Chi2 = 0.04, df = 1 (P = 0.84); I2 = 0%
Test for overall effect: Z = 7.39 (P < 0.00001)
4.7 the second trimester vs the third trimester
Han et al.23	2.5	1.8	257	3.3	1.6	105	16.7%	-0.80 [-1.18, -0.42]
Hu et al.20	6.3	1.94	30	6.42	2.0	30	2.4%	-0.12 [-1.12, 0.88]
Pan et al.25	4.12	1.02	66	4.68	0.9	94	25.3%	-0.56 [-0.87, -0.25]
Subtotal (95% CI)			353			229	44.4%	-0.63 [-0.86, -0.40]
Heterogeneity: Chi2 = 1.99; df = 2 (P = 0.37); I2 = 0%
Test for overall effect: Z = 5.31 (P < 0.00001)
Total (95% CI)			667			618	100%	-0.93 [-1.08, -0.77]
Heterogeneity: Chi2 = 85.30; df = 15 (P < 0.00001); I2 = 82%
Test for overall effect: Z = 11.81 (P < 0.00001)
Test for subgroup differences: Chi2 = 82.22; df = 6 (P < 0.00001) ; I2 = 92.7%