Background Pregnancy in women with systemic lupus erythematosus (SLE) is associated with an increased risk of complications such as preeclampsia and premature birth. Active disease is considered one of the risk factors.
Objectives The aim of this study was to explore the impact of disease activity in pregnant women with SLE on preeclampsia and premature birth, and compare the occurrence with pregnancies from the general obstetric population.
Methods We linked data from RevNatus with data from the Medical Birth Registry of Norway (MBRN). RevNatus is a Norwegian nationwide prospective observational register including women with an inflammatory rheumatic disease when planning pregnancy or after conception. The register was established in 2006 and is administered by the National advisory unit on pregnancy and rheumatic diseases. Women 18 years or older are recruited and followed-up in each trimester of pregnancy and at 6 weeks, 6 months and 12 months after birth. MBRN is a national birth registry. The population constituted all singleton live births recorded in MBRN in the period 2006 – 2014. The births in women diagnosed with SLE in MBRN and included in RevNatus formed the patient group (n=180). The references were all other births (n=498849). We performed logistic regression, and calculated OR for preeclampsia and premature birth in the patient population compared to the references from the general obstetric population. The target population was then split in two groups according to disease activity assessed in the 2nd trimester, and compared to references.
Results Women with SLE had a significantly higher risk of preeclampsia and premature birth than references after adjustment for maternal age, parity and smoking (Table 1).
Concerning preeclampsia, there was no significant difference in women with no disease activity compared to references, whereas active disease resulted in a significantly higher odds. We observed a two-fold and eight-fold increase in risk of premature birth in women with quiescent and active disease, respectively (Table 2).
Conclusions Women with SLE have a higher risk of preeclampsia and premature birth than references from the general obstetric population. Women with active disease in pregnancy are most prone to these complications.
Disclosure of Interest None declared