Metformin Improves Most Outcomes for T2D During Pregnancy- T
Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...
Although metformin is increasingly being used in women with type 2 diabetes during pregnancy, little data exist on the benefits and harms of metformin use on pregnancy outcomes in these women. We aimed to investigate the effects of the addition of metformin to a standard regimen of insulin on neonatal morbidity and mortality in pregnant women with type 2 diabetes.

In this prospective, multicentre, international, randomised, parallel, double-masked, placebo-controlled trial, women with type 2 diabetes during pregnancy were randomly assigned from 25 centres in Canada and four in Australia to receive either metformin 1000 mg twice daily or placebo, added to insulin. Randomisation was done via a web-based computerised randomisation service and stratified by centre and pre-pregnancy BMI in a ratio of 1:1 using random block sizes of 4 and 6.

Women were eligible if they had type 2 diabetes, were on insulin, had a singleton viable pregnancy, and were between 6 and 22 weeks plus 6 days' gestation. Participants were asked to check their fasting blood glucose level before the first meal of the day, before the last meal of the day, and 2 h after each meal. Insulin doses were adjusted aiming for identical glucose targets.

Study visits were done monthly and patients were seen every 1–4 weeks as was needed for standard clinical care. At study visits blood pressure and bodyweight were measured; patients were asked about tolerance to their pills, any hospitalisations, insulin doses, and severe hypoglycaemia events; and glucometer readings were downloaded to the central coordinating centre.

-- Researchers randomly assigned 502 women, 253 (50%) to metformin and 249 (50%) to placebo.

-- Complete data were available for 233 (92%) participants in the metformin group and 240 (96%) in the placebo group for the primary outcome.

-- They found no significant difference in the primary composite neonatal outcome between the two groups.

-- Compared with women in the placebo group, metformin-treated women achieved better glycaemic control, required less insulin, gained less weight and had fewer caesarean births.

-- They found no significant difference between the groups in hypertensive disorders in the metformin group vs in the placebo group.

-- Compared with those in the placebo group, metformin-exposed infants weighed less, fewer were above the 97th centile for birthweight in the metformin group than in the placebo group, fewer weighed 4000 g or more at birth in the metformin group than in the placebo group, and metformin-exposed infants had reduced adiposity measures (mean sum of skinfolds; mean neonatal fat mass.

-- 30 (13%) infants in the metformin group and 15 (7%) in the placebo group were small for gestational age.

-- They found no significant difference in the cord c-peptide between groups. The most common adverse event reported was gastrointestinal.

Conclusively, researchers found several maternal glycaemic and neonatal adiposity benefits in the metformin group. Along with reduced maternal weight gain and insulin dosage and improved glycaemic control, the lower adiposity and infant size measurements resulted in fewer large infants but a higher proportion of small-for-gestational-age infants. Understanding the implications of these effects on infants will be important to properly advise patients who are contemplating the use of metformin during pregnancy.