Associations of COVID-19 lockdown exposure with PTB
A higher PTB rate (5.7% vs 5.3%) and MPTB rate (5.2% vs 4.9%) were
observed in the exposed group compared to the unexposed group in the
total sample. Significant increases in PTB risk (adjusted OR=1.08,
95%CI: 1.05, 1.11) and MPTB risk (adjusted OR=1.09, 95%CI: 1.05, 1.12)
were also observed after adjusting for confounders (Table 3). However,
the association between lockdown and VPTB was not statistically
significant (adjusted OR=1.04, 95%CI: 0.94, 1.16). Subgroup analyses
showed significant associations of lockdown exposure with increases in
PTB and MPTB only among pregnant women <24 GWs on the first
day of lockdown. The OR values varied between 1.10 and 1.20 for PTB and
MPTB.
We also observed a positive association between cumulative exposure dose
to lockdown and PTB risk (Table 3 and Table S3). Each 100 unit increase
in the lockdown exposure during the first 22 GWs was significantly
associated with 1.07 (95%CI: 1.05, 1.09), 1.07 (1.05, 1.08), and 1.12
(1.06, 1.18) times higher risks in PTB, MPTB, and VPTB, respectively.
The adjusted ORs of PTB for the Q1, Q2, Q3 and Q4 quartiles of
cumulative exposure (vs no exposure) were 1.16 (1.08, 1.23), 1.22 (1.14,
1.30), 1.14 (1.07, 1.22), and 1.19 (1.11, 1.27), respectively.