Objective To examine if oral metformin is as effective as insulin in the prevention of fetal macrosomy in pregnancies complicated with gestational diabetes mellitus (GDM).Design Open-label prospective randomised controlled study.Setting Maternity outpatient clinics in a secondary and tertiary level hospital in Finland.Sample One hundred women with GDM who did not attain euglycaemia with diet.Methods Women were randomised to therapy with insulin (n = 50) or oral metformin (n = 50).Main outcome measures Incidence of large-for-gestational-age (LGA) infants and neonatal morbidity.Results There were no statistically significant differences in the incidence of LGA (8.5 versus 10.0%, P = 0.97), mean birthweight, mean cord artery pH or neonatal morbidity between the insulin and metformin groups. Fifteen (31.9%) of the 47 women randomised to metformin needed supplemental insulin. They were more obese (with a body mass index of 36 versus 30 kg/m 2 , P = 0.002), had higher fasting blood glucose levels in an oral glucose tolerance test (6.1 versus 5.0 mmol/l, P = 0.001) and needed medical treatment for GDM earlier (26 versus 31 gestational weeks, P = 0.002) than women who were normoglycemic with metformin. There was a tendency to a higher rate of caesarean sections in the metformin group than in the insulin group (RR 1.9; 95% CI 0.99-3.71).Conclusions Metformin seems to be suitable for the prevention of fetal macrosomy, especially in lean or moderately overweight women developing GDM in late gestation. Women with considerable obesity, high fasting blood glucose and an early need for pharmacological treatment may be more suitable for insulin therapy.

Excess risk was confined to patients using valproate during pregnancy. The risk for malformations was not elevated in offspring of mothers using carbamazepine, oxcarbazepine, or phenytoin (as monotherapy or polytherapy without valproate).

In terms of pain scores, epidural analgesia is superior to that provided by IV remifentanil. However, there was no difference in the pain relief scores between the treatments.

We determined the minimum effective dose of patient-controlled IV remifentanil for labor analgesia. There was wide individual variation in the dose required for effective labor analgesia. Potentially serious side effects, which were observed frequently during remifentanil analgesia, may limit its use in obstetrics.

Maternal complications are frequent in CS, and although performing CS electively reduces the occurrence of complications, the frequency is still high. The complication rate depends on the degree of emergency, and increases with maternal obesity, older age and pre-eclampsia.