What do systematic reviews say?

Metformin vs glibenclamide ‐ neonatal outcomes

It is very uncertain whether metformin changes perinatal mortality compared with glibenclamide ‐ neonatal outcomes (very low certainty).

• Oral anti‐diabetic pharmacological therapies for the treatment of women with gestational diabetes 2017 · Cochrane Headline outcomes only
  RR 0.92 [0.06, 14.55]
  2 studies · 359 participants
  Very low

Metformin vs insulin

• Oral anti‐diabetic agents for women with established diabetes/impaired glucose tolerance or previous gestational… 2017 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 220 participants
  Very low