Rationale:

• ACE inhibitors and angiotensin-receptor blockers have been associated with fetal malformations.
• Although oral hypoglycemics are not thought to be teratogenic, they do not allow for subtle and immediate adjustments in maternal glucose levels.
• No adverse maternal effects are likely to occur with a 9-month hiatus from cholesterol-lowering agents.
• Because HMG-CoA reductase inhibitors have been implicated as possible teratogens, the risks of their use outweigh the benefits to the mother.
• Daily aspirin therapy may lead to maternal and newborn hemorrhage, increased perinatal mortality, intrauterine growth retardation, and teratogenic effects.

Evidence:

• A review revealed numerous case reports of multiple anomalies, including fetal hypocalvaria and renal defects, in babies exposed in utero to ACE inhibitors and angiotensin-receptor blockers (8).
• In a surveillance study of lovastatin exposures during pregnancy, the overall rate of normal outcomes was 85%, and the following rates of occurence were found: congenital anomalies, 4%; spontaneous abortions, 8%; fetal deaths or stillbirths, 1%; and miscellaneous adverse outcomes, 2% (9).
• In one case-controlled study, 3 of 14 newborns exposed to aspirin within 1 week of delivery had minor hemorrhaging compared with 1 of 17 controls (10). In two retrospective studies, mothers of 1,291 malformed infants were found to have consumed aspirin during pregnancy more frequently than mothers of normal infants (11; 12).
• Use of insulin during pregnancy is recommended by consensus of an expert panel (13).

Comments:

• Many diabetic women take a variety of medications; therefore, pre-conception planning should include a review of all drugs and their potential for teratogenesis.