Table 3

Adjusted relative risks (RRs) of birth outcomes, perinatal and postneonatal mortality comparing pregestational diabetes mellitus (PGDM), gestational diabetes mellitus (GDM) to non-diabetic (ND) pregnancies

PGDM versus NDGDM versus ND
Model 1Model 2Model 3Model 1Model 2Model 3
RR (95% CI)RR (95% CI)RR (95% CI)RR (95% CI)RR (95% CI)RR (95% CI)
First Nations
 Perinatal death5.15 (2.97 to 8.92)*4.83 (2.45 to 9.52)*4.96 (2.46 to 9.99)*1.55 (0.86 to 2.81)1.45 (0.70 to 3.01)1.48 (0.71 to 3.08)
 Postneonatal death1.11 (0.27 to 4.60)1.30 (0.30 to 5.61)1.19 (0.27 to 5.24)0.62 (0.19 to 2.00)0.73 (0.22 to 2.41)0.69 (0.21 to 2.31)
 Preterm2.47 (1.91 to 3.19)*2.25 (1.83 to 2.77)*1.30 (0.93 to 1.81)1.35 (1.12 to 1.64)†1.28 (1.04 to 1.57)‡1.19 (0.96 to 1.46)
 SGA0.40 (0.22 to 0.73)*0.34 (0.17 to 0.69)†0.30 (0.13 to 0.67)†0.43 (0.30 to 0.63)*0.47 (0.32 to 0.68)*0.44 (0.30 to 0.64)*
 LGA2.26 (2.05 to 2.49)*2.07 (1.87 to 2.29)*2.06 (1.85 to 2.29)*2.02 (1.89 to 2.16)*1.97 (1.84 to 2.12)*1.94 (1.80 to 2.09)*
 Birth defects1.93 (1.48 to 2.51)*1.78 (1.35 to 2.35)*1.34 (0.92 to 1.94)1.24 (1.02 to 1.51)‡1.21 (0.99 to 1.49)1.18 (0.96 to 1.46)
Non-Indigenous
 Perinatal death1.75 (1.15 to 2.64)†1.82 (1.15 to 2.88)‡1.75 (1.11 to 2.77)‡0.72 (0.53 to 0.98)‡0.75 (0.53 to 1.06)0.74 (0.52 to 1.05)
 Postneonatal death3.53 (1.74 to 7.17)†3.54 (1.73 to 7.21)†3.42 (1.67 to 7.00)†1.40 (0.81 to 2.41)1.47 (0.85 to 2.54)1.45 (0.84 to 2.50)
 Preterm2.24 (2.03 to 2.47)*2.15 (1.94 to 2.38)*1.46 (1.27 to 1.68)*1.44 (1.34 to 1.55)*1.43 (1.33 to 1.54)*1.34 (1.24 to 1.44)*
 SGA0.84 (0.72 to 0.98)‡0.82 (0.70 to 0.96)‡0.78 (0.65 to 0.92)†0.87 (0.81 to 0.94)*0.88 (0.81 to 0.95)*0.85 (0.79 to 0.92)*
 LGA2.43 (2.25 to 2.62)*2.38 (2.16 to 2.62)*2.46 (2.28 to 2.65)*1.82 (1.72 to 1.93)*1.74 (1.64 to 1.84)*1.72 (1.62 to 1.83)*
 Birth defects2.41 (1.88 to 3.09)*2.22 (1.65 to 2.99)*1.52 (1.29 to 1.79)*0.96 (0.88 to 1.04)0.96 (0.88 to 1.05)0.96 (0.88 to 1.05)

  • Model 1: RR adjusted for cluster effects (multiple infants of the same mother) only; model 2: model 1 plus further adjusted for maternal age, education, marital status, parity and rural residence; model 3: model 2 plus further adjusted for chronic hypertension, heart disease, renal disease, genitourinary infection, anaemia and gestational hypertension and pre-eclampsia. Infant sex and year of birth were not included in the adjustment models since they were balanced between comparison groups (all p>0.2) and did not affect the comparisons.

  • *P <0.001.

  • †P <0.006 (Bonferroni adjusted p value cut-off for multiple primary comparisons of interest).

  • ‡0.006≤p<0. 05.

  • LGA, large for gestational age; SGA, small for gestational age.