January 25, 2005
Question from London, United Kingdom:
I have had type 1 diabetes for 24 years and am now 30 weeks pregnant. Before becoming pregnant, I had mild pre-proliferative retinopathy. When I tightened my control significantly (A1c now 5.5) plus pregnancy, this began to deteriorate. Initially, I had macular edema which impaired my vision quite a lot, but the ophthalmologist was confident that it would resolve at the birth. Now, I have new vessel development as well and the retinopathy is speeding up furiously. I am being seen every two weeks at Moorfields Eye Hospital and am getting lasered pretty much every time.
My ophthalmologist is considering recommending early induction. I am on Lantus and Humalog and have recently read that Lantus is not approved for pregnant women as it can aggravate retinopathy. Have you any data on this? Would it be worth changing my regimen (pumps are not an option here)? Would that be of any detriment to the baby? I trust my ophthalmologist and my obstetrician, but they are at different hospitals and do not communicate a great deal and tend to concentrate on their own specialties. As I’m sure you can imagine, I am desperate not to lose my sight. I am already way below the legal limit to drive. Do you think Lantus could be a trigger or am I just unlucky?
I know of one small study involving Type 2 patients on Lantus that demonstrated a higher risk of retinopathy progression versus use of NPH (cited at the Aventis web page at Lantus under Adverse Reactions). To my knowledge, there has been no rigorous study of retinopathy risk or, for that matter, any risk, in pregnant patients using Lantus. Studies have shown that patients on Lantus do achieve a small but statistically significant reduction in glycosylated hemoglobin which should translate into lower risk of retinopathy progression; however, some patients do experience a temporary worsening of retinopathy when blood glucose control improves. This is sometimes referred to as the “glycemic re-entry phenomenon.”
Recent scientific work has clearly demonstrated that increased retinal blood flow is largely responsible for accelerated retinopathy progression, and we would therefore expect that conditions associated with increased retinal blood flow (e.g. hyperglycemia, hypertension and pregnancy) might cause retinopathy to worsen.
Additional comments from Dr. Bill Jones:
I could not find a reference regarding Lantus and progression of retinopathy on Medline. I would be interested in the information that you have. Rapid improvement in glucose control can exacerbate retinopathy. Pregnancy can also promote retinopathy, depending on how severe the condition when the pregnancy started. If you are having significant deterioration, then early delivery may be indicated. However, the earliest I would recommend would be 34 weeks gestation. I doubt that changing insulin type would be of any benefit.