CL<38mm P 95%CI I2 RR Exclude the literature name The p values were after the sensitivity analysis Publication bias Quality of evidence
ptd<34 0.002* 0.69 0.55,0.88 46% 3.05 - - - moderate
ptd<37 0.06 0.92 0.84,1.00 28% 1.97 - - - moderate
miscarriage 0.16 0.74 0.48,1.13 41% 1.4 - - - moderate
sptd<34 0.03* 0.76 0.6,0.97 70% 2.24 Nicolaided 2015 0.002* + low
sptd<37 0.32 0.93 0.79,1.08 0% 1 - - - moderate
SM 0.16 0.68 0.40,1.15 0% 1.42 - - - moderate
DW <0.00001* 0.37 0.26,0.48 83% 6.31 Norman 2021 <0.00001* + low
C 0.86 0.94 0.46,1.91 0% 0.17 - - - moderate
VI 0.88 1.05 0.58,1.88 0% 0.16 - - - moderate
VD <0.00001* 3.57 2.71,4.72 97% 9 - - + moderate
<34PPROM 0.56 1.25 0.59,2.64 66% 0.58 Goya2015 0.08! + low
PPROM 0.02* 2.17 1.12,4.17 64% 2.31 Leim2013 0.004! + low
C-section 0.7 1.02 0.92,1.14 0% 0.39 - - + low
VB <0.00001* 1.56 1.32,1.83 93% 5.34 Norman 2021 <0.00001* - moderate
intrauterine death or stillbirth 0.18 1.41 0.86,2.33 0% 1.36 - - + low
neonatal death 0.006* 0.42 0.23,0.78 78% 2.78 Leim2013 0.84 + low
<2500 <0.00001 0.74 0.57,0.81 90% 6.02 Merced 2019 0.003* + low
<1500 0.9 1.02 0.77,1.34 0% 0.13 - - + low
NE 0.0002* 0.29 0.15,0.56 0% 3.68 - - - moderate
IVH 0.37 0.73 0.36,1.47 54% 0.86 Norman 2021 0.05 + low
RDS 0.09 0.76 0.55,1.04 0% 1.7 + low
S 0.009* 0.57 0.38,0.87 52% 2.61 Merced 2019 0.07 + low