Optimal Glycemic Control, Pre-Eclampsia, and Gestational Hypertension in Women With Type 1 Diabetes in the Diabetes and Pre-Eclampsia Intervention Trial

  1. for the Diabetes and Pre-eclampsia Study Group
  1. 1School of Nursing and Midwifery, Queen’s University Belfast, Belfast, U.K.
  2. 2Centre for Public Health, School of Medicine, Dentistry, and Biomedical Sciences, Queen’s University Belfast, Belfast, U.K.
  3. 3Department of Diabetes, Aberdeen Royal Infirmary, Aberdeen, U.K.
  4. 4Department of Diabetes, St. John’s Hospital at Howden, West Lothian, U.K.
  5. 5Department of Obstetrics and Gynecology, St Mary’s Hospital for Women and Children, Manchester, U.K.
  6. 6Regional Centre for Endocrinology and Diabetes, Royal Victoria Hospital, Belfast, U.K.
  1. Corresponding author: David R. McCance, david.mccance{at}belfasttrust.hscni.net.

Abstract

OBJECTIVE To assess the relationship between glycemic control, pre-eclampsia, and gestational hypertension in women with type 1 diabetes.

RESEARCH DESIGN AND METHODS Pregnancy outcome (pre-eclampsia or gestational hypertension) was assessed prospectively in 749 women from the randomized controlled Diabetes and Pre-Eclampsia Intervention Trial (DAPIT). HbA1c (A1C) values were available up to 6 months before pregnancy (n = 542), at the first antenatal visit (median 9 weeks) (n = 721), at 26 weeks’ gestation (n = 592), and at 34 weeks’ gestation (n = 519) and were categorized as optimal (<6.1%: referent), good (6.1–6.9%), moderate (7.0–7.9%), and poor (≥8.0%) glycemic control, respectively.

RESULTS Pre-eclampsia and gestational hypertension developed in 17 and 11% of pregnancies, respectively. Women who developed pre-eclampsia had significantly higher A1C values before and during pregnancy compared with women who did not develop pre-eclampsia (P < 0.05, respectively). In early pregnancy, A1C ≥8.0% was associated with a significantly increased risk of pre-eclampsia (odds ratio 3.68 [95% CI 1.17–11.6]) compared with optimal control. At 26 weeks’ gestation, A1C values ≥6.1% (good: 2.09 [1.03–4.21]; moderate: 3.20 [1.47–7.00]; and poor: 3.81 [1.30–11.1]) and at 34 weeks’ gestation A1C values ≥7.0% (moderate: 3.27 [1.31–8.20] and poor: 8.01 [2.04–31.5]) significantly increased the risk of pre-eclampsia compared with optimal control. The adjusted odds ratios for pre-eclampsia for each 1% decrement in A1C before pregnancy, at the first antenatal visit, at 26 weeks’ gestation, and at 34 weeks’ gestation were 0.88 (0.75–1.03), 0.75 (0.64–0.88), 0.57 (0.42–0.78), and 0.47 (0.31–0.70), respectively. Glycemic control was not significantly associated with gestational hypertension.

CONCLUSIONS Women who developed pre-eclampsia had significantly higher A1C values before and during pregnancy. These data suggest that optimal glycemic control both early and throughout pregnancy may reduce the risk of pre-eclampsia in women with type 1 diabetes.

  • Received February 8, 2011.
  • Accepted May 2, 2011.

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This Article

  1. Diabetes Care
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