Metformin compared with insulin in the management of gestational diabetes mellitus: a randomized clinical trial.
OBJECTIVE
To evaluate the effect of metformin and insulin in glycemic control and compare pregnancy outcome in women with gestational diabetes mellitus (GDM).


METHODS
This randomized controlled trial was conducted in GDM women with singleton pregnancy and gestational age between 20 and 34 weeks who did not achieve glycemic control on diet were assigned randomly to receive either metformin (n=80) or insulin (n=80). The primary outcomes were maternal glycemic control and birth weight. The secondary outcomes were neonatal and obstetric complications.


RESULTS
Two groups were comparable regarding the maternal characteristics. Two groups were similar in mean FBS (P=0.68) and postprandial measurements (P=0.87) throughout GDM treatment. The neonates of metformin group had less rate of birth weight centile >90 than insulin group (RR: 0.5, 95% CI: 0.3-0.9, P=0.012). Maternal weight gain was reduced in the metformin group (P<0.001). Two groups were comparable according to neonatal and obstetric complications (P>0.05). In metformin group 14% of women needed to supplemental insulin to achieve euglycemia.


CONCLUSIONS
Metformin is an effective and safe alternative treatment to insulin for women with GDM. This study does not show significant risk of maternal or neonatal adverse outcome with the use of metformin.
Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Women Hospital, Tehran University of Medical Sciences, Tehran, Iran.
Shirin
S
Niromanesh
Azin
A
Alavi
Fatemeh Rahimi
FR
Sharbaf
Nooshin
N
Amjadi
Sanaz
S
Moosavi
Soheila
S
Akbari
D000328:Adult; D001724:Birth Weight / Q000187:drug effects; D001786:Blood Glucose / Q000032:analysis; D016640:Diabetes, Gestational / Q000097:blood / Q000188:drug therapy*; D004359:Drug Therapy, Combination / Q000009:adverse effects; D005260:Female; D005320:Fetal Macrosomia / Q000517:prevention & control*; D006801:Humans; D006943:Hyperglycemia / Q000517:prevention & control*; D007003:Hypoglycemia / Q000517:prevention & control*; D007004:Hypoglycemic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D007336:Insulin, Isophane / Q000009:adverse effects / Q000627:therapeutic use*; D059012:Lost to Follow-Up; D008687:Metformin / Q000009:adverse effects / Q000627:therapeutic use*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D016037:Single-Blind Method; D015430:Weight Gain / Q000187:drug effects
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007336:Insulin, Isophane; D008687:Metformin