Impact of pregnancy on the progression of diabetic retinopathy in Type 1 diabetes.
OBJECTIVE
To evaluate the impact of pregnancy on the progression of diabetic retinopathy in women with Type 1 diabetes mellitus and to identify risk factors for the progression of retinopathy during pregnancy.


METHODS
One hundred and seventy-nine pregnancies in 139 women with pregestational Type 1 diabetes were studied prospectively between January 1990 and December 1998. Dilated fundal examination was performed at booking, 24 weeks and 34 weeks or 4-6 weekly if retinopathy present at booking. Data were collected on glycaemic control (HbA(1c)) throughout pregnancy.


RESULTS
Progression to proliferative retinopathy was seen in four (2.2%) pregnancies while moderate progression was seen in a further five (2.8%) pregnancies. Progression of retinopathy was significantly increased in women with duration of diabetes 10-19 years compared with duration < 10 years (10% vs. 0%; P = 0.007) and in women with moderate to severe background retinopathy at booking (30% vs. 3.7%; P = 0.01). Although HbA(1c) at booking was higher (7.5% vs. 6.6%; P = 0.08) and the fall in HbA(1c) between booking and 24 weeks was greater (1.6% vs. 1.2%; P = 0.2) in those women showing progression of retinopathy, these changes were not significant.


CONCLUSIONS
Progression of retinopathy in pregnancy was uncommon (5.0% pregnancies) but was significantly more common in women with duration of diabetes > 10 years and in women with moderate to severe retinopathy at baseline. Laser therapy was needed in 2.2% pregnancies, which is much lower than that reported in earlier studies. Diabet. Med. 18, 573-577 (2001)
Temple
R C
RC
Bertram Diabetes Centre, Norfolk and Norwich Healthcare NHS Trust, Norwich, UK. Louise.Couch@norfolk-norwich.thenhs.com
Aldridge
V A
VA
Sampson
M J
MJ
Greenwood
R H
RH
Heyburn
P J
PJ
Glenn
A
A
D017668:Age of Onset; D001786:Blood Glucose / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000097:blood / Q000503:physiopathology* / Q000628:therapy; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D011225:Pre-Eclampsia / Q000453:epidemiology; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000097:blood / Q000503:physiopathology*; D013997:Time Factors
D001786:Blood Glucose; D006442:Glycated Hemoglobin