SPTB and gestational diabetes: Some exposure to smoking throughout pregnancy did not increase the risk of PE, sPTB, FGR or GDM, but was associated with lower birthweight (β = –169 g, 95% CI: –292 g to –46 g) and birthweight Z-score (β = –0.30, 95% CI: –0.53 to –0.07) compared with no exposure to smoking throughout pregnancy.