Short summary

Systemic lupus erythematosus (SLE) is an autoimmune rheumatic disease often seen in younger women. Pregnancy may affect the SLE disease adversely, and SLE disease activity may influence pregnancy outcome for mother and child negatively. As pregnancies in females with SLE due to the risk of maternal and fetal complications are classified as "high-risk-pregnancies", extensive monitoring is done at specialized university hospital clinics. Danish experiences are warranted as SLE is characterized by different disease-courses in different populations and health care systems. Danish results may help to identify relevant risk profiles. This would improve information to SLE patients considering pregnancy and offer clinicians knowledge to optimize surveillance and treatment.

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Description of the cohort

Women with SLE and one or more pregnancies will be compared to women without SLE.

Multiple pregnancies will be excluded. 

Data and biological material

In a follow-up design a cohort of all pregnant SLE patients are identified from the Danish National Patient Registry (NPR), which holds nationwide data on all inpatients visits to any Danish hospital since 1977 and all hospital outpatient visits since 1995. In NPR diagnoses of SLE (M32.1-9) and pregnancy complications are registered according to the International Classification of Disease (ICD-8) from 1977 to 1993 and from 1994 (ICD-10). Females diagnosed with SLE and one or more pregnancies are included amounting approximately 500 SLE patients during the period 1997 through 2016.

From the Civil Registration System (CRS) an age-matched cohort of pregnant women without SLE at the time of matching are identified. For each SLE patient 20 females from the background population are identified.

Pregnancy outcomes for the study population including clinical data about infants are retrieved from the Medical Birth Register (MBR) where data about all Danish pregnancies are registered routinely. All deliveries except twin births will be included.

Maternal outcomes recovered from the NPR include hypertension, preeclampsia, eclampsia, cesarean section, vaginal birth, postpartum hemorrhage, pulmonary embolism, deep venous thrombosis and cerebral venous thrombosis Furthermore, probable pregnancy related events (up to 3 months after delivery) such as obstetric pulmonary embolism, deep venous thrombosis and cerebral venous thrombosis will be included.

Fetal data and outcomes retrieved from the MBR include gender of the fetus, Apgar score, birth weight, gestational week, missed abortion, intrauterine death, stillbirth, neonatal death, preterm birth, and small for gestational age.

Adverse pregnancy outcomes including spontaneous abortion, missed abortion and preeclampsia will be recovered from NPR.

Finally, data on potential confounders such as maternal BMI and smoking in pregnancy will be obtained from the MBR.

Outcomes of SLE pregnancies will be compared with outcomes of the matched cohort. 

Collaborating researchers and departments

Department of Rheumatology, Odense University Hospital

• Consultant Anne Voss, PhD

Department of Gynaecology and Obstetrics

• Consultant Lise-Lotte Torvin Andersen

OPEN - Odense Patient data Explorative Network

• Postdoc Mette Bliddal, PhD