Volume 181 - Issue 3
Metformin therapy and diabetes in pregnancy
Authors: David Simmons, Barry N J Walters, Janet A Rowan and H David McIntyre
Med J Aust 2004; 181 (3): 174-175. || doi: 10.5694/j.1326-5377.2004.tb06220.x
Published online: 2 August 2004
Published online: 2 August 2004
David Simmons,* Barry N J Walters,† Janet A Rowan,‡ H David McIntyre§
* Professor of Medicine, Waikato Clinical School, Waikato Hospital, Hamilton, NZ; † Clinical Associate Professor, Department of Women’s and Children’s Health, King Edward Memorial Hospital, Subiaco, WA; ‡ Physician, Department of Obstetrics, National Women's Hospital, Auckland, NZ; § Director of Endocrinology, Mater Hospital, Brisbane, QLD. simmonsdATwaikatodhb.govt.nz
In reply: We thank Gardiner et al for their commendation and support for our update on the safety of metformin in pregnancy.1 We agree with their analysis regarding the timing of the use of metformin during lactation.
Nevertheless, we would like to highlight that the safety of metformin can not be assumed from the studies they quote, as these included very few subjects. Such studies, helpful as they may be, provide no imprimatur for the long-term safety for the growing infant and subsequent adult. While no babies had side effects reported during these studies, this may not be the case for other babies.
Should a woman decide against the use of insulin to control hyperglycaemia postnatally, then the risk of potential known and unanticipated side effects of metformin should be discussed while obtaining informed consent for metformin use. However, during this discussion, it would also be prudent to weigh-up metformin use against breastfeeding with continued hyperglycaemia, an activity associated with greater obesity and impaired glucose tolerance in the offspring.2
References
- Simmons D, Waiters BNJ, Rowan JA, McIntyre HD. Metformin therapy and diabetes in pregnancy. Med J Aust 2004; 180: 462-464. <eMJA full text>
- Plagemann A, Franke K, Harder T, Kohlhoff R. Long-term impact of neonatal breastfeeding on body weight and glucose tolerance in children of diabetic mothers. Diabetes Care 2002; 25: 16-22. i1085566