Background To establish a register to determine disease activity, pregnancy surveillance and safety of medication during pregnancy and lactation, and monitoring this group as a quality register.

Methods The Norwegian pregnancy register RevNatus is designed as a nation-wide, web-based longitudinal observational cohort study with 17 participating centres. Pregnant patients or patients planning a pregnancy with confirmed diagnosis of inflammatory rheumatic disease are eligible to be enrolled. The women are preferred enrolled before conception and with registrations each trimester, 6 weeks, 6 and 12 months postpartum. At baseline diagnosis, sociodemographic parameters, disease activity, anti-rheumatic medication, obstetric history, comorbidities and antibody status are reported. The register has been approved by the Norwegian Data Inspectorate and is run by The Norwegian National Advisory Unit on Pregnancy and Rheumatic Diseases.

Results From February 2016 – January 2018 597 women were included in RevNatus, mean age at inclusion was 30,8 (17–44). Among these patients 4% had only completed primary school, 24% secondary education and 72% had completed a university education. At inclusion 4% were smoking (general population 11%) and 6% used snuff (general population 12%). At registration 6 weeks after delivery 3% were smoking and 2% used snuff. Alltogether 346 women were registered with a control 6 weeks after delivery. Of these, 31 women experienced spontaneous abortion and one therapeutic abortion. Among the remaining, 314 had live born infants including 7 twin births and one triplet birth. Among the women with registration 6 week postpartum, 260 (75%) women were diagnosed with chronic inflammatory arthritis including rheumatoid arthritis, spondylarthritis, juvenile idiopathic arthritis and unspecified arthritis. Correspondingly, 79 (23%) women were registered with inflammatory connective tissue disease (SLE, MCTD, poly-dermato myositis, systemic sclerosis), 3 with vasculitic disease (Takayasu’s arteritis, Mb Behcet), and 5 with primary anti-phospholipid antibody (APS) syndrome. Mean disease duration (SD) for all diagnoses was 6,5 years.^6,8 Corresponding, mean disease duration in women with RA was 6,7 (4,1) years, in women with SLE 9,4 (6,1) years and in women with JIA 20,7 (7,3) years. Mean gestational age at birth for all diagnoses was 38,7 (2,5) weeks. The gestational age was lowest in SLE women 37,9 (2,59) weeks. Mean gestational week for spontaneous abortion was at 11 weeks. Mean birthweight (SD) was 3268^758,7 gram in offspring of women with RA and 3133 gram in women with SLE. Overall 71 (22%) women had caesarean deliveries, 14% were acute and 9% planned caesarean deliveries. Six weeks postpartum 258 women (82,7%) were breastfeeding their babies.

Conclusions The Norwegian pregnancy register RevNatus was established to study the course and outcomes of pregnancies in women with inflammatory rheumatic diseases as well as increased knowledge on the use and safety of treatments during pregnancy and lactation. The results of the register gives data to monitor the quality of the treatment for this group of patients.

Disclosure of Interest None declared