Baseline characteristics of the study population
| Characteristics | Total population (n=44) | APOs patients (n=13) | No APOs patients (n=31) | p Value* |
|---|---|---|---|---|
| Age (years)† | 32.3 (4.6) | 32.2 (5.6) | 32.3 (4.2) | 0.69 |
| Ethnicity | ||||
| Hispanic | 4 (9%) | 2 (15%) | 2 (6%) | 0.67 |
| Non-Hispanic | 40 (91%) | 11 (85%) | 29 (93%) | |
| Race | ||||
| White | 36 (82%) | 8 (73%) | 28 (93.3%) | 0.11 |
| Non-white | 5 (11%) | 3 (23%) | 2 (6%) | |
| BMI‡ | ||||
| <25 | 28 (64%) | 5 (38%) | 23 (74%) | 0.04 |
| 25–30 | 10 (23%) | 6 (46%) | 4 (13%) | |
| >30 | 6 (14%) | 2 (15%) | 4 (13%) | |
| SLE | 16 (36%) | 4 (30%) | 12 (39%) | 0.74 |
| Number previous pregnancies | 1.7 (1.6) | 1.6 (1.6) | 1.7 (1.7) | 0.80 |
| APS | 26 (59%) | 12 (92%) | 14 (45%) | 0.004 |
| History of thrombosis | 13 (29%) | 9 (69%) | 4 (13%) | 0.0001 |
| History of obstetrical complications | 18 (41%) | 8 (61%) | 10 (31%) | 0.07 |
| Treatment during pregnancy | ||||
| Hydroxychloroquine | 17 (39%) | 6 (46%) | 11 (35%) | 0.44 |
| Corticosteroid | 4 (9%) | 1 (8%) | 3 (10%) | 1.0 |
| Aspirin | 36 (82%) | 10 (77%) | 26 (84%) | 0.67 |
| Heparin | 32 (73%) | 12 (92%) | 20 (64%) | 0.07 |
| Heparin and/or aspirin | 42 (95%) | 13 (100%) | 29 (94%) | 0.37 |
| Azathioprine | 1 (2%) | 0 (0%) | 1 (3.2%) | |
| IVIG once per month | 1 (2%) | 1 (8%) | 0 (0%) | |
| aPL positive at screening§ | ||||
| LAC | 17 (39%) | 9 (69%) | 8 (27%) | 0.01 |
| aCL IgG | 26 (59%) | 9 (69%) | 17 (55%) | 0.37 |
| aβ2GPI IgG | 23 (52%) | 8 (61%) | 15 (50%) | 0.48 |
| aβ2GPI and/or aCL IgM | 8 (9%) | 1 (8%) | 7 (23%) | 0.4 |
| Triple aPL positivity | 6 (14%) | 5 (38%) | 1 (3%) | 0.008 |
*Fisher's exact or Mann–Whitney tests compared patients with APOs to patients without APOs.
†Age was expressed as mean (SD). Other characteristics were expressed as number (% of the total).
‡BMI comparison was done between groups <25 vs ≥25.
§APL positivity for each test was defined as lupus anticoagulant: RVVT, dilute TTI or PTT LA with confirmation; aCL: IgG ≥40 GPL units; IgM ≥40 MPL units; and anti-β2GPI: IgG ≥40 GPL units; IgM ≥40 MPL units. To be considered positive, each test met these criteria at least twice between 6 weeks and 5 years apart of which one must be during the PROMISSE pregnancy at a core lab.4 Triple aPL positivity was defined as having all three aPL tests positive.
aCL, anticardiolipin antibodies; aPL, antiphospholipid antibodies; APOs, adverse pregnancy outcomes; APS, antiphospholipid syndrome; aβ2GPI, anti-β2 glycoprotein I antibodies; BMI, body mass index; IU, international unit; IVIG, intravenous immunoglobulin therapy; LAC, lupus anticoagulant; SLE, systemic lupus erythematosus.