INS and preterm premature rupture of the membranes: After adjustment for the known risk factors of PPROM (Table 2), the risk factors for PPROM only were BMI <18.5 kg/m2 (aOR: 1.91 (1.04–3.52)), history of PPROM (aOR: 2.61 (1.13–6.03)), nulliparity (aOR: 2.56 (1.77–3.70)), gestational diabetes (aOR: 1.83 (1.14–2.94)), low level of education (aOR: 2.34 (1.08–5.05)), standing while working (aOR: 1.62 (1.04–2.53)), and insulin intake (aOR: 2.51 (1.37–4.59)).