No. of participants No. of participants Gestational length (week, Mean±SD) Gestational length (week, Mean±SD) Mean difference in gestational length (week) Mean difference in gestational length (week)
Unexposed group Exposed group b Unexposed group Exposed group b Crude β (95% CI) Adjusted β (95% CI) *
Gestational week at the beginning of the Level I lockdown
All
493496
101900
38.74±1.46
38.66±1.46
-0.08 (-0.09, -0.07)
-0.06 (-0.07, -0.05)
Conception during the lockdown
64645
11317
38.72±1.52
38.64±1.49
-0.08 (-0.11, -0.05)
-0.04 (-0.07, -0.01)
Prior to 4th
53300
10937
38.71±1.50
38.64±1.50
-0.07 (-0.10, -0.04)
-0.10 (-0.14, -0.07)
4th -7th
50973
10494
38.67±1.52
38.52±1.54
-0.14 (-0.17, -0.11)
-0.13 (-0.16, -0.09)
8th -11th
48926
10237
38.70±1.50
38.58±1.54
-0.12 (-0.15, -0.08)
-0.10 (-0.13, -0.07)
12th -15th
46255
9844
38.73±1.51
38.61±1.55
-0.11 (-0.15, -0.08)
-0.11 (-0.14, -0.07)
16th -19th
45913
9539
38.74±1.48
38.63±1.52
-0.11 (-0.14, -0.08)
-0.10 (-0.13, -0.06)
20th -23rd
41017
8830
38.74±1.49
38.64±1.52
-0.10 (-0.14, -0.07)
-0.10 (-0.13, -0.06)
24th -27th
40358
8750
38.68±1.49
38.66±1.44
-0.02 (-0.06, 0.01)
-0.01 (-0.04, 0.03)
28th -31st
38146
8101
38.72±1.39
38.63±1.36
-0.09 (-0.12, -0.06)
-0.07 (-0.10, -0.04)
32nd -36th
47382
10213
38.74±1.21
38.73±1.18
-0.01 (-0.03, 0.02)
0.02 (-0.01, 0.04)
37th - 41st
16581
3638
39.40±0.92
39.41±0.93
0.01 (-0.02, 0.04)
0.03 (0.01, 0.07)
Exposure dose (Mean±SD) Exposure dose (Mean±SD) Gestational length (week, Mean±SD) Gestational length (week, Mean±SD) Mean difference in gestational length (week) Mean difference in gestational length (week)
Unexposed group Exposed group Unexposed group Exposed group Crude β (95% CI) Adjusted β (95% CI) *
Cumulative exposure dose in the first 22 weeks during the Level I to the Level III lockdown a
Per 100 unit increase in all participants 0±0 195.08±82.21 38.74±1.45 38.61±1.52 -0.06 (-0.07, -0.05) -0.05 (-0.06, -0.04)
Categories of cumulative exposure dose
Unexposed group 0±0 - 38.74±1.45 - Reference Reference
Q1 (<132) - 73.40±38.11 - 38.64±1.52 -0.10 (-0.13, -0.08) -0.09 (-0.11, -0.07)
Q2 (132-225) - 178.66±27.17 - 38.59±1.54 -0.15 (-0.17, -0.12) -0.13 (-0.16, -0.11)
Q3 (226-263) - 247.18±10.58 - 38.58±1.51 -0.16 (-0.18, -0.13) -0.14 (-0.16, -0.11)
Q4 (≥264) - 278.80±8.59 - 38.62±1.51 -0.12 (-0.14, -0.10)* -0.09 (-0.11, -0.07)
P for trend test < 0.001