Commonly, women with type 2 diabetes are taking sulphonylureas and/or metformin prior to conception. Hitherto, these have little place in the management of diabetes in pregnancy, although the use of metformin has been attracting increasing interest in recent years. The main anxiety about sulphonylureas in pregnancy is the possibility of further increasing the degree of fetal hyperinsulinaemia by direct drug-induced stimulation. Sulphonylureas, with the exception of glyburide, cross the placenta and have been implicated as a direct cause of neonatal hypoglycaemia. The long-acting agent chlorpropamide is particularly dangerous and should not be used in the last 4 weeks of gestation. There is no convincing evidence that these drugs are teratogenic. Metformin, which does not cross the placenta, has been reported to be useful in some obese individuals with type 2 diabetics who are inadequately controlled by diet. There are a range of theoretical and practical benefits from using metformin therapy instead of insulin therapy in later pregnancy, but there is insufficient data currently to support its routine usage. Several reports of the use of metformin during pregnancy in women with polycystic ovary syndrome have not shown adverse pregnancy outcomes. In these women, taking metformin before, during the first trimester or throughout pregnancy reduced rates of spontaneous abortion and normal growth development, and normal maternal morbidity and mortality rates are observed. There is also a reduced subsequent risk of gestational diabetes with continued use of metformin during pregnancy. Most authorities, however, continue to recommend that metformin is not routinely used except where any potential harm is outweighed by the benefits of metformin usage, e.g., severe insulin resistance or refusal to use insulin. Glitazones are unlicensed for use in pregnancy and are not recommended.
Pregnancy: Oral hypoglycaemic agents
Tagged Chlorpropamide, Glyburide, Insulin, Metformin. Bookmark the permalink.