Women with type 1 diabetes (T1D) should undergo ophthalmologic follow-up both before and during pregnancy. Severe prepregnancy diabetic retinopathy should be treated before women consider becoming pregnant, according to research results published in Diabetes Care.
To evaluate the progression rate of diabetic retinopathy during pregnancy among women with T1D, researchers conducted a retrospective study at a single center in Lille, France, between 1997 and 2015.
During consecutive pregnancies of 24 weeks or longer, women underwent monthly diabetes and obstetric care and twice weekly phone calls with a specialized nurse to assess glucose control and adjust insulin as needed. All participants performed blood glucose self-monitoring.
The final cohort included 499 pregnancies in 375 participants (mean age, 29.7±4.8 years; 50.1% nulliparous; mean T1D duration, 13.6±8.1 years). Before conceiving, 30.3% of patients had diabetic retinopathy, 7.6% had diabetic nephropathy, and 2.2% had diabetic neuropathy.
Mean prepregnancy hemoglobin A1c (HbA1c) was 7.6% (±1.6). During pregnancy, 53.1% of women were treated with continuous subcutaneous insulin infusion (CSII), and pregnancy-induced hypertension and preeclampsia rates were 11.3% and 6.3%, respectively.
Among all pregnancies, 47.2% were complicated by diabetic retinopathy. Most patients had diabetic retinopathy identified before pregnancy (64%). Progression in diabetic retinopathy stage occurred in only 15.9% of the prepregnancy diabetic retinopathy patients, and most of that took place during the first and second trimesters.
Among the 85 cases recognized during pregnancy, 89.4% ended with mild diabetic retinopathy. Only 1 case became severe, and only 1 case progressed to proliferative diabetic retinopathy. In pregnancies with worsening diabetic retinopathy, 15.6% of progressions advanced only 1 stage.
Investigators had ophthalmologic data for postpartum year 1 for 270 pregnancies. Within this group, only 4.1% of patients progressed, while 9.3% experienced diabetic retinopathy regression.
In a bivariate analysis, investigators found that nulliparity, diabetes duration of 10 years or more, and elevated prepregnancy HbA1c were “significantly associated” with an increased risk for diabetic retinopathy progression. Conversely, laser photocoagulation before pregnancy and the presence of prepregnancy diabetic retinopathy were significantly associated with a lower risk.
Mixed logistic regression models further evaluated first-order interactions with prepregnancy diabetic retinopathy and found that no significant first-order interactions, with the exception of CSII treatment. In those with prepregnancy diabetic retinopathy, CSII treatment was associated with a decreased risk of diabetic retinopathy progression (odds ratio [OR], 0.24; 95% CI, 0.09-0.62) and an increased risk in pregnancies without prepregnancy diabetic retinopathy (OR, 1.72; 95% CI, 1.02-2.89).
Study limitations include a lack of available data on difference over time regarding HbA1c levels, types of insulin, or percentages of women using insulin pumps. Researchers could not determine how these differences may have affected study results.
“We should consider ophthalmologic follow-up crucial for women with type 1 diabetes before and during pregnancy,” the researchers concluded. “In women with a longer duration of diabetes, we should take care to treat severe [diabetic retinopathy] before women consider pregnancy. Unplanned pregnancies and nulliparous patients would also benefit from intensive ophthalmologic follow-up.”
Bourry J, Courteville H, Ramdane N, et al. Progression of diabetic retinopathy and predictors of its development and progression during pregnancy in patients with type 1 diabetes: a report of 499 pregnancies. Diabetes Care. 2021;44(1):181-187. doi:10.2337/dc20-0904