No. of participants
No. of participants
No. of participants
No. of participants
Gestational length (week, Mean±SD) Gestational length (week, Mean±SD) Gestational length (week, Mean±SD) Gestational length (week, Mean±SD) Mean difference in gestational length (week) Adjusted β (95% CI) * Mean difference in gestational length (week) Adjusted β (95% CI) *
P for modification effects of infant sex
Male Male Female Female Male Male Female Female Male Female
Unexposed group
Exposed group a Unexposed group Exposed group a Unexposed group Exposed group a
Unexposed group
Exposed group a
Gestational week during the Level I lockdown
All 263153 54349 230343 47551 38.66±1.48 38.58±1.48 38.82±1.43 38.74±1.44 -0.06 (-0.08, -0.05) -0.06 (-0.08, -0.05) > 0.05
No. of participants
No. of participants
No. of participants
No. of participants
PTB rate (N, %)
PTB rate (N, %)
PTB rate (N, %)
PTB rate (N, %)
PTB risk Adjusted OR (95%CI) * PTB risk Adjusted OR (95%CI) *
P for modification effects of infant sex
Male Male Female Female Male Male Female Female Male Female
Unexposed group Exposed group a Unexposed group Exposed group a Unexposed group Exposed group a Unexposed group Exposed group a
Gestational week during the Level I lockdown
All 254522 52471 222393 45791 14873 (5.8) 3269 (6.2) 10758 (4.8) 2324 (5.1) 1.09 (1.04, 1.13) 1.08 (1.03, 1.13) > 0.05