Table 2:

Summary conclusions of included studies with relation to hypertensive disorders of pregnancy

Study	Summary Statements
Chen et al, 2018	In women with hemoglobin A1c measured in early pregnancy, this study did not find a significantly increased risk for preeclampsia among women with hemoglobin A1c 5.7–6.4% versus hemoglobin A1c < 5.7%. The lack of significance may be explained by more women with baseline hemoglobin A1c 5.7–6.4% receiving diabetes medications, fewer experiencing excessive weight gain, and 67% having minimally elevated hemoglobin A1c (5.7% or 5.8%).
Mañé et al, 2017	In women with hemoglobin A1c measured in early pregnancy, this study suggests an increased risk of preeclampsia in women with hemoglobin A1c 5.9–6.4% versus hemoglobin A1c < 5.9%
Osmundson et al, 2016	In women with first trimester hemoglobin A1c of 5.7–6.4%, this underpowered study suggests no decrease in hypertensive disorders of pregnancy risk from a diet-based lifestyle intervention, with blood glucose monitoring, ± insulin versus usual care.
Rowan et al, 2016	In women with hemoglobin A1c of 5.9–6.6% at gestational diabetes mellitus diagnosis, this study suggests early identification and treatment of gestational diabetes mellitus (63.4% included metformin) is associated with a lower risk for preeclampsia compared to later identification and treatment of gestational diabetes mellitus (56.3% included metformin).
Hughes et al, 2014	In women with hemoglobin A1c measured in early pregnancy who were not treated for gestational diabetes mellitus during the index pregnancy, this study suggests an increased risk of preeclampsia in women with hemoglobin A1c 5.9–6.4% versus hemoglobin A1c < 5.9%