Metformin Versus Insulin in Gestational Diabetes

• pregnancy induced hypertension [ Time Frame: up to on the average 40 weeks of gestation ] [ Designated as safety issue: Yes ]
• maternal weight gain [ Time Frame: up to on the average 40 weeks of gestation ] [ Designated as safety issue: No ]
• pre-eclampsia [ Time Frame: up to on the average 40 weeks of gestation ] [ Designated as safety issue: Yes ]
• mode of delivery [ Time Frame: delivery ] [ Designated as safety issue: No ]
• gestational weeks at delivery [ Time Frame: delivery ] [ Designated as safety issue: Yes ]
• induction of delivery [ Time Frame: delivery ] [ Designated as safety issue: No ]
• shoulder dystocia [ Time Frame: delivery ] [ Designated as safety issue: Yes ]
• neonatal hypoglycemia [ Time Frame: 0-24 h after delivery ] [ Designated as safety issue: Yes ]
• neonatal hyperbilirubinemia [ Time Frame: 0-3 days after delivery ] [ Designated as safety issue: Yes ]
• Apgar score at 5 min after delivery [ Time Frame: 5 minutes after delivery ] [ Designated as safety issue: Yes ]
• neonate transfer to intensive care unit [ Time Frame: 0-5 days after delivery ] [ Designated as safety issue: Yes ]
• child outcome at 2 years [ Time Frame: 2 years after birth ] [ Designated as safety issue: Yes ]
  neuropsychological and motor skills testing

• pregnancy induced hypertension [ Time Frame: up to on the average 40 weeks of gestation ] [ Designated as safety issue: Yes ]
• maternal weight gain [ Time Frame: up to on the average 40 weeks of gestation ] [ Designated as safety issue: No ]
• pre-eclampsia [ Time Frame: up to on the average 40 weeks of gestation ] [ Designated as safety issue: Yes ]
• mode of delivery [ Designated as safety issue: No ]
• gestational weeks at delivery [ Designated as safety issue: Yes ]
• induction of delivery [ Designated as safety issue: No ]
• shoulder dystocia [ Designated as safety issue: Yes ]
• neonatal hypoglycemia [ Designated as safety issue: Yes ]
• neonatal hyperbilirubinemia [ Designated as safety issue: Yes ]
• Apgar score at 5 min after delivery [ Designated as safety issue: Yes ]
• neonate transfer to intensive care unit [ Designated as safety issue: Yes ]
• child outcome at 2 years [ Designated as safety issue: Yes ]
  neuropsychological and motor skills testing

Gestational diabetes is traditionally treated with insulin. Metformin is a peroral drug used worldwide in the treatment of type 2 diabetes and also in a few studies on patients with gestational diabetes. The investigators aim is to compare insulin and metformin in the treatment of gestational diabetes. The investigators hypothesis is that there is no difference between insulin and metformin treated mothers in the main outcome criteria (birth weight, neonatal complications).

• Drug: metformin
  metformin 1 g twice daily or maximum tolerated dose less than 2 g daily
• Drug: insulin
  subcutaneous Neutral Protamine Hagedorn (NPH) insulin and/or rapid acting insulin analog adjusted according to plasma glucose values until delivery

• Active Comparator: Metformin
  Intervention: Drug: metformin
• Active Comparator: insulin
  Intervention: Drug: insulin

Inclusion Criteria:

• Mothers with gestational diabetes who had at least twice plasma glucose at fasting > 5.4 mmol/L and/or 1 hour postprandial value > 7.7 mmol/L at 24 to 32 gestational weeks

Exclusion Criteria:

1. Fasting glucose > 7.0 mmol/L or 1 hour postprandial plasma glucose > 11.0 mmol/L or Glycosylated hemoglobin A1c (HbA1c) > 7.0%
2. Renal, hepatic or cardiac failure
3. Pregestational use of metformin
4. Pregnancy with multiple fetuses