Effect modification by infant sex in the associations of
lockdown exposure with gestational length and PTB
Subgroup analyses showed similar associations of Level I lockdown with
gestational length [adjusted β=-0.06 (95%CI: -0.08, -0.05) week vs
adjusted β= -0.06 (-0.08, 0.05) week] or risk of PTB [adjusted
OR=1.09 (95%CI: 1.04, 1.14) vs adjusted OR=1.08 (1.03, 1.13)] in male
infants and in female infants (Table 4). There were no significant sex
interaction (P>0.05) in these associations.