Glycaemic Control in Women With Type 1 Diabetes and Preeclampsia Risk: A Nationwide Cohort Study

Area of Science:

• Reproductive Medicine
• Endocrinology
• Public Health

Background:

• Preeclampsia is a serious pregnancy complication.
• Glycaemic control in women with type 1 diabetes (T1DM) before conception is critical.
• Large-scale data on peri-conceptional glycaemic control and preeclampsia risk are limited.

Purpose of the Study:

• To investigate the association between peri-conceptional glycaemic control and preeclampsia risk in women with T1DM.
• To quantify the dose-response relationship between glycated haemoglobin (HbA1c) levels and preeclampsia incidence.

Main Methods:

• Population-based nationwide cohort study in Sweden (2003-2019).
• Included singleton pregnancies (N=1,689,301), with 4,429 women diagnosed with T1DM.
• Assessed peri-conceptional HbA1c levels (≤90 days from conception) and preeclampsia diagnosis using ICD codes.

Main Results:

• Women with T1DM had a significantly higher risk of preeclampsia (aRR 4.7) compared to women without diabetes.
• Preeclampsia risk showed a dose-response relationship with increasing peri-conceptional HbA1c levels.
• The adjusted risk for early preterm preeclampsia was substantially higher (aRR 7.2) in women with T1DM.

Conclusions:

• Women with T1DM experience a markedly increased risk of preeclampsia.
• Poorer glycaemic control around conception is associated with a dose-dependent increase in preeclampsia risk.
• Optimizing HbA1c levels prior to conception is essential for mitigating preeclampsia risk in T1DM pregnancies.