Disease
Activity in women with SLE during pregnancy and the first year post partum

Background/Purpose: Disease activity measured by validated
methods has been sparsely examined during and after pregnancy in women with SLE.
The purpose was to examine disease activity by the Lupus Activity Index in Pregnancy(LAI-P) during pregnancy and in the first year post partum (pp).

Methods: RevNatus is a research database were patients are included nationwide at
all departments of Rheumatology in Norway. Women who plan pregnancy or are
already pregnant  are
included after informed consent. Data for the SLE- cohort was obtained in 2007
– 2015. LAI-P is a modified version of Lupus Activity Index (LAI), with a good
ability to measure disease activity and diagnose disease flares in pregnancy. To
explore variation in disease activity throughout pregnancy and after birth disease
activity was measured by LAI-P/LAI at 6 time points: in each trimester, 6
weeks, 6 months and 12 months 
pp. A general mixed model was applied, using the last time point
as reference, and comparing  baseline (12
months post partum) with measures in each trimester,
6 weeks and 6 months pp. LAI and LAI-P measures disease activity on a
continuous scale from 0 – 3; 0 indicating no disease activity and 3 indicating
very high disease activity. As the assumption of normal distribution was not
fulfilled, the dependant variable was categorized. We
adjusted for mothers age in 1st trimester, disease duration, parity,  prednisolon
use and  Plaquenil
use .

Results:  
A total of 145 pregnancies in 127 women with SLE
were included in the analysis. More than half (51,6%)
of the measures on disease activity indicated remission and only 6,3% of the
measures exceeded 0,5. A change in disease activity > 0,25 is perceived as a
clinically relevant change,  and the four
categories chosen were no disease activity (LAI-P =0, ), very low disease
activity (LAI-P 0,01 – 0,25), low disease activity (LAI-P >0,25 – 0,50),
and  moderate disease activity or above (LAI-P>0,50),
corresponding to category 0,1,2 and 3 in the figure. It illustrates the
percentage of each category at the separate time points, showing that the
disease activity declines during pregnancy and increase after delivery. There
is a significantly  increased odds of
higher disease activity 6 and 12 months pp.

Conclusion:  In 145 pregnancies in women with SLE, the disease activity decreased
during pregnancy, but increased during the first year after delivery.  This points to the
importance of tight control not only during pregnancy, but also in the first
year after delivery in women with SLE.