Table 1

Baseline and disease characteristics in SLE and APS pregnancies

Pregnancies (n)SLEPrimary APS
Pathway
N=16
Historical
N=43
Pathway
N=25
Historical
N=28
Maternal characteristics
Age at conception*33 (31–35)32 (27–34)31 (30–37)30 (28–34)
Caucasian11 (68.8)29 (67.4)18 (72.0)14 (50.0)
Smoking during pregnancy1 (6.3)1 (2.3)3 (12.0)3 (10.7)
BMI (kg/m2)*24.9 (23.2–29.2)23.5 (21.5–25.8)26.2 (21.4–31.6)25.9 (19.6–28.3)
Chronic hypertension4 (25.0)6 (14.0)2 (8.0)0 (0.0)
Obstetric characteristics
Nulliparous12 (75.0)21 (48.8)17 (68.0)12 (42.9)
Singleton pregnancy16 (100.0)42 (97.7)24 (96.0)27 (96.4)
History of miscarriage2 (12.5)9 (20.9)22 (88.0)†16 (57.1)
History of pre-eclampsia2 (12.5)7 (16.3)4 (16.0)6 (21.4)
Specific APS history
Thrombotic APS3 (18.8)1 (2.3)78 (32.0)12 (42.9)
Obstetric APS1 (6.3)1 (2.3)14 (56.0)†5 (17.9)
Thrombotic and obstetric APS0 (0.0)0 (0.0)3 (12.0)†11 (39.3)
History of thromboembolic events4 (25.0)6 (14.0)10 (40.0)†23 (82.1)
Lupus anticoagulant5 (31.3)3 (7.0)15 (60.0)23 (82.1)
Anticardiolipin antibodies4 (25.0)†0 (0.0)10 (40.0)†24 (85.7)
Anti-β2-glycoprotein-I antibodies3 (18.8)0 (0.0)12 (48.0)14 (77.8)
Number of positive aPL tests
16 (37.5)†3 (7.0)14 (56.0)†5 (17.9)
20 (0.0)0 (0.0)10 (40.0)11 (39.3)
32 (12.5)0 (0.0)1 (4.0)†12 (42.9)
Specific SLE history
Duration SLE disease (years)*9 (6–11)9 (4–12)
SLICC damage index*0 (0–1)0 (0–1)
EULAR/ACR criteria*23 (12–38)†17 (10–22)
Secondary APS4 (25.0)†2 (4.7)
Serological Active Clinically Quiescent3 (18.8)0 (0.0)
Clinically active SLE <6 months before1 (6.3)4 (9.3)
History of LN10 (62.5)20 (46.5)
I0 (0.0)2 (4.7)
II0 (0.0)1 (2.3)
III2 (12.5)3 (7.0)
IV5 (31.3)9 (20.9)
V2 (12.5)5 (11.6)
ANA14 (87.5)29 (67.4)
Anti-Ro/SS-A11 (68.7)23 (53.5)
Anti-La/SS-B4 (25.0)13 (30.2)
Anti-dsDNA7 (43.8)18 (41.9)
Low C3 before pregnancy‡8 (50.0)8 (18.6)
Low C4 before pregnancy‡4 (25.0)3 (7.0)
Medication before pregnancy
Only HCQ or no immunosuppressants3 (18.8)21 (48.8)25 (100.0)28 (100.0)
Corticosteroid11 (68.8)18 (41.9)
 Dose in mg*10.0 (7.5–10.0)†5 (4.4–8.1)
Hydroxychloroquine16 (100.0)†25 (58.1)2 (8.0)1 (3.6)
 Dose in mg*350 (200–400)400 (200–400)400 (400–400)400 (400–400)
Tacrolimus7 (43.8)†1 (2.3)
 Dose in mg*6 (4–6)3 (3)
Azathioprine7 (43.8)14 (32.6)
 Dose in mg*150 (100–150)100 (50–125)
Medication in pregnancy
LMWH4 (25.0)†4 (9.3)21 (84.0)20 (71.4)
Acetylsalicylic acid16 (100.0)†22 (51.2)21 (84.0)†16 (57.1)
  • Data depicted as numbers (%) unless otherwise specified.

  • *Median (IQR).

  • †Shows a significant difference with two-sided α<0.05.

  • ‡Low C3 defined as <0.9 g/L and low C4 defined as <95 mg/L

  • ACR, American College of Rheumatology; aPL, antiphospholipid antibodies; APS, antiphospholipid syndrome; BMI, body mass index; dsDNA, double stranded DNA; EULAR, European League Against Rheumatism; HCQ, hydroxychloroquine; LMWH, low-molecular-weight heparin; ; LN, lupus nephritis; SLICC, Systemic Lupus International Collaborating Clinics; triple-positive, positivity for lupus anticoagulant+anticardiolipin+anti-β2-glycoprotein 1.