Metformin (pictured) is a first line anti-diabetic drug. Its use, moreover, extends to two pregnancy related conditions, namely polycystic ovaric syndrome (a disease associated with menstrual dysfunction) and gestational diabetes mellitus (a condition characterized by high blood glucose levels during pregnancy). Nevertheless, the long term effects of prenatal metformin exposure remain elusive.

Using a mouse model, Henriikka Salomäki, University of Turku, Finland, and colleagues reveled that metformin’s prenatal exposure alters the expression of genes involved in the metabolism of lipids and lipoproteins. Moreover, a reduction in body water content as well as an increase in fat tissues were observed in metformin-exposed offspring which, during adult development, underwent a high fat diet. In these circumstances, male mice also showed an impaired glucose tolerance. Thus, metformin exerts metabolic long-term effects which need to be taken into account when using this drug during pregnancy.

• Prenatal metformin exposure in mice programs the metabolic phenotype of the offspring during a high fat diet at adulthood,
  H. Salomäki, L. H. Vähätalo, K. Laurila, N. T. Jäppinen, A. Penttinen, L. Ailanen, J. Ilyasizadeh, U. Pesonen, M. Koulu,
  PLoS ONE 2013, 8(2), e56594.
  DOI: 10.1371/journal.pone.0056594