Large for gestational age (>90th percentile) 82 per 1,000 136 per 1,000 (91 to 203) RR 1.66 (1.11 to 2.48) 8,186 (1 observational study) LOW 1 Macrosomia (>4,000g) 155 per 1,000 174 per 1,000 (121 to 250) RR 1.12 (0.78 to 1.61) 8,186 (1 observational study) LOW 1 *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio Working Group grades of evidence High quality: We are very confident that the true effect lies close to that of the estimate of the effect Moderate quality: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different Low quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect Source: Hughes et al 2014. Note that this was included in MoH NZ 2014 but is presented spearatley here to inform the analysis. Data from a single observational study with low rates of participation in reference testing Pregnancy outcomes associated with early treatment compared to later treatment for women with HbA1c 41–49 mmol/mol Patient or population: Pregnant women Setting: New Zealand Intervention: treatment (<24 weeks) Comparison: Later treatment (24 weeks) Outcomes Anticipated absolute effects* (95% CI) Relative effect (95% CI) № of participants (studies) Quality of the evidence (GRADE) Comments Risk with later treatment (24 wk) Risk with early treatment (<24 wk) Perinatal death 0 per 1,000 0 per 1,000 (0 to 0) not estimable 285 (1 observational study) LOW 1
1.3 Harms and benefits of testing Study ref Design LoE N Aim, setting, population, measurements Results Comments () Cohort III-2 946 Aim: To examine whether women with an HbA1c of 41–49 mmol/mol (5.9–6.6%) are at higher risk than women with an HbA1c of <41 mmol/mol (5.9%) and whether pregnancy outcomes are improved if treated at <24 weeks’ gestation. Setting: New Zealand Population: Women with diabetes in pregnancy diagnosed by early HbA1c testing or subsequent OGTT at <34 weeks’ gestation Methods: Data were extracted from the hospital database. Women with HbA1c 41–49 mmol/mol (5.9–6.6%) were divided into those seen <24 weeks (Early, n=134) and those seen ≥ 24 weeks (Later, n=151). Those with HbA1c < 41 mmol/mol (5.9%) were labelled Other GDM (n=661). were higher rates of adverse outcomes in the Later group than the Other GDM group (pre-eclampsia 8.0 vs 2.4%, P=0.001, preterm birth 16.6 vs 8.2%, P=0.002, neonatal admission 15.5 vs 9.2%, P=0.02). Outcomes were similar between the Early group and Other GDM group (pre-eclampsia 1.5 vs 2.4%, P=0.5, preterm birth 10.5 vs 8.2% P=0.4, neonatal admission 13.6 vs 9.2%, P=0.12). Comparing the Early and Later groups, the Early group had less pre-eclampsia, 1.5 vs 8.0%, adjusted P=0.03. Other outcomes were not statistically different. 1.4 Uptake of HbA1c compared to glucose challenge test and oral glucose tolerance test Study ref Design LoE N Aim, setting, population, measurements Results Comments