Syed et al. BMC Public Health 2011, 11(Suppl 3):S2 http://www.biomedcentral.com/1471-2458/11/S3/S2 I2=95% and p-value <0.10, a random effects model was also applied which indicated that the results were statisti- cally insignificant (RR=3.38, 95%CI 0.49-23.34). Delphi results Figure 6 summarizes the estimates (medians) from the Delphi consensus for the effect of intervention of dia- betes screening and management versus no specific iden- tification or care for women with diabetes. The experts determined the effect to be 10% reduction in antepartum stillbirth (or intrauterine death). (interquartile range of 5% to 30%) and 10% reduction in intrapartum stillbirth (interquartile range of 3.5% to 25%). These figures have been recommended for use in the LiST model. Discussion This systematic review attempts to summarize the evi- dence in the literature regarding the prevention and management of gestational and pregestational diabetes and the effect on stillbirths. We have performed meta- analyses where possible to estimate impact of prevention and treatment strategies on stillbirth. We found substan- tial differences in clinical and methodological approaches across all studies with variability in interventions, defini- tions of outcomes, study design and risk of bias. Although the focus was on interventions having an impact on stillbirth risk we found that there was a lack of data regarding this outcome in most studies. Some studies included present stillbirths as part of perinatal mortality. With regard to screening strategies no rando- mized controlled trial has been reported that directly evaluates the risks and benefits of early diabetes screen- ing [81]. Our systematic review identified 4 studies focusing on intensive treatment of diabetes versus con- ventional management. A reduction of 80% was observed in stillbirth risk with intensive management Figure 6 Box plots for the Delphi results on diabetes screening and management during pregnancy. Page 9 of 12 but was not statistically significant. A systematic review by Alwan et al. 2009 [4] focusing on treatment of gesta- tional diabetes reported positive benefits on maternal preeclampsia (five trials, 1255 women; RR = 0.95, 95% CI 0.80 to 1.12) and macrosomia when any specific treatment is utilized versus routine antenatal care for GDM, however, results were not significant. A recent review by Horvath et al. 2010 [94] focusing on the same comparison reported similar effects on risk of macroso- mia, shoulder dystocia and preeclampsia. For the comparison of optimal versus suboptimal control of diabetes two cohort studies [42,70] reporting stillbirth risk were identified. Three studies [26,61,70] reported peri- natal mortality for the same comparison; and a 60% reduc- tion in risk of perinatal mortality was seen in women with optimal glucose control, which was statistically significant. A similar comparison was performed by Inkster and collea- gues 2006 [5]. Similar findings were reported in their review regarding perinatal mortality. Increased perinatal mortality was associated with poor glycaemic control, pooled odds ratio 3.03 (95% CI: 1.87 to 4.92). For the intervention of continuous subcutaneous insulin infusion versus conventional multiple insulin injections a systematic review by Mukhopadhay et al. 2007 [95] was identified. This review also reported that no significant dif- ference in glycemic controls or pregnancy outcomes including stillbirths was seen when the two different treat- ment strategies (continuous subcutaneous insulin versus conventional daily injections) were compared. It is noted that studies included in the pooled analyses had small sample sizes and further studies with larger sample sizes may be needed for more conclusive results [95]. In the treatment of diabetes during pregnancy the spot- light is often on insulin therapy; however, in recent years studies have been done that assess the impact of oral hypoglycemic agents and metformin on pregnancy out- comes. A recent systematic review concluded that no sig- nificant differences were found in maternal glycemic control or cesarean delivery rates between the insulin and glyburide groups. There was a higher proportion of infants with neonatal hypoglycemia in the insulin group (8.1%) compared with the metformin group (3.3%) (P-value: 0.008). Also the rate of congenital malformations, which contribute to stillbirth risk, did not differ between preg- nancies treated with insulin and those treated with oral agents [96]. Another systematic review [4] reported a 54% reduction in the rates of cesarean section in women who received oral hypoglycemic therapy compared to insulin. Currently, data are insufficient to conclude that the use of oral hypoglycemic agents reduces the risk of stillbirth in women who have GDM. Diabetes in pregnancy is also associated with higher rates of miscarriage, pre-eclampsia, preterm labour and higher rates of fetal malformation [97]; neural tube defect,