Treating Diabetes When You're Pregnant
Keeping blood glucose levels as close to normal as possible is critical in pregnancy, but the physiology of pregnancy can make that hard work. If you are already taking insulin before you conceive, you will naturally need more as the pregnancy progresses. In addition, your doctor may decide to change the type of insulin you are taking. And if you have type 2 that's managed with diet, exercise, oral medications, or a combination of those, you will probably begin taking insulin once you get pregnant (or even before).
Safe and Sound
Why change your pre-pregnancy regimen? That's because only a few types of insulin (and no diabetes pills) are generally considered safe for the developing baby. "People are trying desperately to find a [safe] pill," says Lois Jovanovic, MD, MACE, head of the Sansum Diabetes Research Institute in Santa Barbara, Calif., but studying any untested treatment that could affect a child's short- and long-term health demands the utmost caution. "We can't know [until] a generation later what [a pill] did to the kid."
No insulin is formally approved for use during pregnancy. Human insulins—regular (Humulin R, Novolin R/ReliOn) and NPH (Humulin N, Novolin N/ReliOn)— are generally considered safe and effective. Studies suggest that the mealtime insulins lispro (Humalog) and aspart (NovoLog) are reasonably safe for pregnant women. Less is known about the mealtime insulin glulisine (Apidra) and the background insulins glargine (Lantus) and detemir (Levemir) in pregnancy. Some doctors will prescribe these insulins if regular and NPH aren't doing the job, while others feel that they should be avoided until more research is done.
No oral medications used to treat type 2 diabetes are currently approved for use during pregnancy, but this may change. A 2008 study in the New England Journal of Medicine compared insulin and metformin in women with gestational diabetes, a form of diabetes that develops during pregnancy and usually goes away after childbirth. It found comparable results in terms of newborn health. But since metformin is known to cross the placental barrier, researchers are continuing to study whether it is safe. Another medicine being evaluated is the sulfonylurea glyburide; studies have shown mixed results so far. And it's worth noting, says Jovanovic, that while these medications may be found to work for gestational diabetes, oral meds may not be sufficient for blood glucose control in women with type 2 diabetes because pregnancy increases insulin resistance.
Insulin remains the medication of choice for a safe pregnancy. New options may become available, but even now there are ways for women with diabetes to get the treatment they need to have healthy babies.