Table 2. Primary outcome and prespecified neonatal outcomes in the modified intention to treat population and subgroup discordant for definition of GDM*.
| mITT population | Subgroup discordant for definition of GDM* | |||||||
|---|---|---|---|---|---|---|---|---|
| SWE-GDM criteria (n = 22 797) |
WHO-2013 criteria (n = 24 283) |
WHO-2013 vs. SWE-GDM | SWE-GDM criteria (n = 956) |
WHO-2013 criteria (n = 1 239) |
WHO-2013 vs. WE-GDM | |||
| Adjusted 1† RR (95% CI) |
Adjusted 2‡ RR (95% CI) |
Adjusted 1† RR (95% CI) |
Adjusted 2‡ RR (95% CI) | |||||
| Primary outcome | ||||||||
| Large for gestational age (>90th percentile) § [16] | 2 584 (11.4) |
2 790 (11.5) |
0.96 (0.92–1.01) P† = 0.11 |
0.97 (0.91–1.02) P‡ = 0.26 |
273 (28.8) |
278 (22.5) |
0.83 (0.71–0.97) P† = 0.018 |
0.87 (0.75–1.01) P‡ = 0.076 |
| Secondary neonatal outcome | ||||||||
| Composite neonatal outcome | 288 (1.3) |
365 (1.5) |
1.14 (0.99–1.31) P† = 0.062 |
1.18 (0.99–1.39) P‡ = 0.050 |
15 (1.6) |
13 (1.0) |
0.18 (0.08–0.38) P† < 0.001 |
0.19 (0.09–0.40) P‡ < 0.001 |
| Respiratory distress | 148 (0.65) |
202 (0.83) |
1.43 (1.11–1.84) P† = 0.006 |
1.51 (1.12–2.02) P‡ = 0.006 |
6 (0.63) |
6 (0.48) |
NA | NA |
| Spinal cord injury | 0 (0.00) |
2 (0.01) |
NA | NA | 0 (0.00) |
0 (0.00) |
NA | NA |
| Peripheral nerve/brachial plexus injury | 16 (0.07) |
21 (0.09) |
1.24 (0.76–2.02) P† = 0.39 |
NA | 1 (0.10) |
2 (0.16) |
NA | NA |
| Basal/depressed skull fracture | 0 (0.0) |
0 (0.0) |
NA | NA | 0 (0.0) |
0 (0.0) |
NA | NA |
| Clavicular fracture | 31 (0.14) |
35 (0.14) |
0.76 (0.36–1.59) P† = 0.47 |
0.77 (0.36–1.66) P‡ = 0.51 |
2 (0.21) |
1 (0.08) |
NA | NA |
| Long bone fracture | 3 (0.01) |
0 (0.00) |
NA | NA | 0 (0.0) |
0 (0.0) |
NA | NA |
| Cranial hemorrhage | 37 (0.16) |
54 (0.22) |
1.65 (1.241–2.18) P† < 0.001 |
1.71 (1.26–2.33) P‡ < 0.001 |
1 (0.10) |
0 (0.0) |
NA | NA |
| Stillbirth (≥22 gestational weeks) or neonatal death (day 0–28) | 69 (0.30) |
83 (0.34) |
0.76 (0.54–1.08) P† = 0.13 |
0.76 (0.55–1.06) P‡ = 0.11 |
5 (0.52) |
1 (0.08) |
NA | NA |
| Need of therapeutic cooling | 20 (0.09) |
29 (0.12) |
1.44 (0.40–5.13) P† = 0.58 |
NA | 0 (0.0) |
4 (0.32) |
NA | NA |
| Preterm birth (<37 weeks) | 943 (4.1) |
1 144 (4.7) |
1.07 (0.96–1.19) P† = 0.23 |
1.08 (0.96–1.22) P‡ = 0.21 |
39 (4.1) |
76 (6.1) |
1.18 (0.69–2.01) P† = 0.54 |
1.26 (0.72–2.22) P‡ = 0.42 |
| Small for gestational age (<10th percentile) § [16] | 2 525 (11.1) |
2 733 (11.3) |
0.98 (0.91–1.05) P† = 0.52 |
0.98 (0.90–1.06) P‡ = 0.61 |
56 (5.9) |
104 (8.4) |
1.12 (0.88–1.44) P† = 0.35 |
1.13 (0.81–1.57) P‡ = 0.46 |
| Exploratory neonatal outcomes | ||||||||
| Macrosomia (birth weight ≥4 500 g) § | 679 (3.0) |
658 (2.7) |
0.78 (0.71–0.85) P† < 0.001 |
0.79 (0.72–0.87) P‡ < 0.001 |
86 (9.1) |
48 (3.9) |
0.31 (0.19–0.53) P† < 0.001 |
0.32 (0.19–0.54) P‡ < 0.001 |
| Large for gestational age (>2 SD) §[16] | 1 019 (4.5) |
1 065 (4.4) |
0.30 (0.83–0.99) P† = 0.025 |
0.91 (0.84–0.99) P‡ = 0.028 |
157 (16.6) |
141 (11.4) |
0.73 (0.57–0.93 P† = 0.009 |
0.77 (0.62–0.96) P‡ = 0.020 |
| Small for gestational age (<2 SD) §[16] | 659 (2.9) |
779 (3.2) |
1.04 (0.85–1.28) P† = 0.67 |
1.03 (0.82–1.29) P‡ = 0.80 |
9 (0.95) |
36 (2.9) |
1.45 (0.75–2.81) P† = 0.27 |
1.52 (0.71–3.27) P‡ = 0.28 |
| Birth weight (g) § | 3 528 (530) |
3 512 (543) |
−22 (−35 to −10) P† < 0.001 |
−21 (−37 to −5) P‡ = 0.012 |
3 761 (552) |
3 572 (561) | −138 (−186 to 90) P† < 0.001 |
−125 (−174 to −76) P‡ < 0.001 |
| Birth length (cm) ¶ | 50.3 (2.4) |
50.2 (2.5) |
−0.08 (−0.13 to −0.04) P† < 0.001 |
−0.06 (−0.12 to −0.01) P‡ = 0.019 |
50.9 (2.2) |
50.3 (2.4) |
−0.30 (−0.48 to −0.12) P† = 0.001 |
−0.31 (−0.42 to −0.21) P‡ < 0.001 |
| Gestational age (days) | 278.1 (12.1) |
277.7 (12.7) |
−0.47 (−0.62 to −0.33) P† < 0.001 |
−0.46 (−0.63 to 0.28) P‡ < 0.001 |
277.4 (10.7) |
274.8 (11.1) |
−1.52 (−2.36 to −0.68) P† < 0.001 |
−1.60 (−2.44 to −0.76) P‡ < 0.001 |
Data are reported as n (%) or mean (SD).
*The cohort of women with fasting and 2-h plasma glucose cut off between the WHO-2013 criteria and SWE-GDM criteria (fasting plasma glucose 5.1–6.9 and/or 2-h plasma glucose 8.5–8.8/8.9/9.9 mmol/L), untreated before and treated after the switch.
†Analysed with multilevel mixed model adjusted for centre as random factor and period (January–March, April–June, July–September, and October–December) as fixed factor. Mixed Poisson model for binary outcomes (gives relative risk ratios as association measures), mixed multi-nominal for categorical outcomes (gives odds ratios as association measures), mixed linear model for continuous outcomes (gives mean differences as association measures), and mixed negative binomial model for count data (gives mean ratios as association measures).
‡Adjusted for mother’s age modelled by a linear, squared, and cubic term, chronic hypertension, smoking, snuff, country of birth, and parity. Multiple imputation used for missing data on potential confounding variables.
§In the modified intention to treat population, there were missing values for 90 neonates in the SWE-GDM group and for 74 in the WHO-2013 group. In the subgroup, there were missing values for 9 neonates in the SWE-GDM group and for 2 in the WHO-2013 group.
CI, confidence interval; GDM, gestational diabetes mellitus; mITT, modified intention to treat; NA, not applicable; NICU, neonatal intensive care unit; RR, relative risk ratio; SD, standard deviation.