Objectives To study maternal and foetal outcomes in two consecutive pregnancies in women with renal and non-renal systemic lupus erythematosus (SLE) in relation to disease flares, preeclampsia and obstetric outcomes.

Material and Methods A single-centre retrospective observational cohort study was conducted during 2000–2018 at the Karolinska University Hospital, Stockholm, Sweden. Medical records of two consecutive pregnancies in 51 SLE patients were studied. Data of disease activity was evaluated by The Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) 6 months prior to conception where active disease was defined as a score >4.

Results Twenty patients had history of lupus nephritis (LN) prior to the first pregnancy, 31 had non-renal disease. Seven of the 20 (35%) LN patients developed a total of 10 renal flares. Three patients flared during both pregnancies; the other seven flares were seen in the second pregnancy. However, no significant increase in LN flares between pregnancies was found (p=0.3). Three LN patients had a SLEDAI score > 4 before pregnancy, one of these developed a renal flare. No renal flare was seen in the non-renal group.

There were 17 non-renal flares in the total patient cohort, 4 in the LN group (20%) (all at second pregnancy) and 13 flares in 8/31 (25,8%) patients in the non-renal group. Five non-LN patients flared during both pregnancies. Two non-LN patients had SLEDAI>4 before pregnancy, both flared. SLE flares were more common in the non-renal group compared to the LN group at first (p=0.038) but not second pregnancy (ns).

A higher proportion of patients with history of LN received low-dose acetylsalicylic acid, immunosuppressive and antihypertensive treatment compared to patients with non-renal SLE (table 1).

Women with history of LN delivered earlier at the second pregnancy compared to women without LN (p<0.01). Only LN patients developed preeclampsia (4 in each pregnancy) (p=0.010 compared to non-LN patients). There were no differences in other adverse pregnancy outcomes between the investigated subgroups.

Conclusions Despite a higher treatment load in SLE patients with the history of kidney involvement, renal flares, preeclampsia and early delivery were more common compared to non-renal SLE, pointing to an increased need of surveillance in LN patients during pregnancy.