A follow‐up of a randomised study of metformin and insulin in gestational diabetes mellitus: growth and development of the children at the age of 18 months

Abstract

Objective To compare the growth and development of children born to mothers with gestational diabetes mellitus (GDM) requiring pharmacological treatment, and randomised to treatment with metformin or insulin.Design Follow-up of a randomised controlled trial (RCT) comparing metformin and insulin treatment of GDM.Setting Data were gathered during routine visits to child welfare clinics at the ages of 6, 12, and 18 months, including weight and height measurements, and assessment of motor, social, and linguistic development.Sample The children of mothers with GDM randomised to metformin (n = 47) or insulin (n = 50) treatment during pregnancy.Methods Data were collected from the structured questionnaire filled in at the child welfare clinics.Main outcome measures The growth and development of the children until the age of 18 months.Results Children exposed to metformin were significantly heavier (10.47 versus 9.85 kg, 95% CI 0.04-1.20) at the age of 12 months and taller and heavier (83.9 vs 82.2 cm, 95% CI 0.23-3.03, 12.05 vs 11.32 kg, 95% CI 0.04-1.43) at the age of 18 months. The mean ponderal index (PI) did not differ significantly. The motor, social, or linguistic development evaluated at the age of 18 months did not differ between the groups.Conclusions Children prenatally exposed to metformin were heavier at the 12 months measurements and taller and heavier at the 18 months measurements than those exposed to insulin, but their body composition defined by PI did not differ. Over the short term, metformin does not seem to be harmful with regards to early motor, linguistic, or social development.

Neurodevelopment of Two-Year-Old Children Exposed to Metformin and Insulin in Gestational Diabetes Mellitus

“…19 Seventy four percent of invited children attended to our study, the study population (146 children) being larger than in previous studies evaluating the effect of metformin use during pregnancy to neurodevelopment of offspring. 11,15 In addition, we applied standardized and internationally used neurodevelopmental and neurological tests. The limitation of the study is that the sample size, although adequate for detecting medium or large group differences, may not be adequate for detecting small differences between groups.…”

“…Until now, there are only 2 follow-up studies 14,15 of children born to patients with gestational diabetes mellitus (GDM) treated with metformin or insulin. In the largest follow-up study of Metformin in Gestational diabetes (MiG) study, 1 the body composition was measured at the age of 2 years.…”

“…The developmental screening did not show any harmful effects of prenatal exposure to metformin. 15 We have recently performed a randomized controlled trial comparing metformin with insulin in 217 patients with gestational diabetes mellitus (GDM). 2 Since the detailed neurological and motor development in the offspring exposed to metformin in utero is poorly documented in studies published previously, we have now performed a neurodevelopmental follow-up study using standardized developmental and neurological measures; the Bayley Scales of Infant and Toddler Development (Bayley-III) and the Hammersmith Infant Neurological Examination.…”

Is it worth treating gestational diabetes: if so, when and how?

“…One study found no differences in motor, social or linguistic development at 18 months of age [47]. In the same study, the degree of adiposity was similar in both the metformin and insulin groups, but children exposed to metformin antenatally were heavier at the age of 12 months and both taller and heavier at the age of 18 months [47].…”

“…Until now, offspring exposed to metformin have been found to have more favourable fat distribution, and similar blood pressure at the age of 2 years compared with offspring in the insulin group [45,46]. One study found no differences in motor, social or linguistic development at 18 months of age [47]. In the same study, the degree of adiposity was similar in both the metformin and insulin groups, but children exposed to metformin antenatally were heavier at the age of 12 months and both taller and heavier at the age of 18 months [47].…”