Comparison of pregnancy outcomes between indigenous and non-indigenous lupus patients.

Aim: To compare pregnancy outcomes between IA and non IA lupus patients.

Background: Pregnancy in lupus patients confers an increased risk of maternal and fetal morbidity. There are no data on pregnancy outcomes for indigenous Australian (IA) patients with lupus.

Methods: Using state-wide longitudinal hospital morbidity data, we studied 702 pregnancies in IA (n = 31) and non-indigenous (NI) patients with lupus (n = 357) in Western Australia and compared rates for live birth (LB), preterm birth (PB) and gestational complications in the period 1985-2015. Results are presented as medians or frequency.

Results: IA patients had proportionally more pre-existing renal disease (35 vs 13%, P < 0.01) and lower socio-economic status (P = 0.02). Age at first pregnancy was lower in IA patients (27 vs 30 years, P < 0.001), recorded gravidity was similar (2 vs 2, P > 0.6) and elective termination (n = 138) was more frequent in NI than IA pregnancies (21.1 vs 4.8%, P < 0.01). For continued pregnancies (59 in IA and 505 in NI), respective outcomes were as follows: LB 84.7% versus 91.5% (P = 0.15), spontaneous abortion 13.5% versus 6.9% (P = 0.13), (pre-)eclampsia 8% versus 9.9% (P = 0.89), PB 12% versus 13.4% (P = 0.98) and caesarean delivery 30% versus 47.2% (P = 0.02). Gestational diabetes (26% vs 6.1%), renal flares (20% vs 5.6%) and infections (22% vs 6.3%) were all more frequent in IA lupus pregnancies (all P < 0.001).

Conclusions: The burden of comorbidities was higher in IA patients with lupus due to renal flares, gestational DM and infections. Although PB rates were overall high, they were, however, similar for IA and NI lupus pregnancies, as were LB rates.