Table 1.
Baseline characteristics, co-interventions, and pregnancy outcomes of the study cohort
|
PIERS-ML group |
External validation group |
|||||
|---|---|---|---|---|---|---|
| Women with an adverse outcome at any time after first assessment (N=1083) | Women without an adverse outcome (N=7760) | p value* | Women with an adverse outcome at any time after first assessment (N=121) | Women without an adverse outcome (N=2780) | p value* | |
| Health system | ||||||
| National per capita gross domestic product (US$) | 41 064 (7501–46 594) | 43 586 (28 206–50 114) | <0·0001 | 42 330 (41 064–43 043) | 42 330 (40 361–43 043) | 0·0427 |
| National maternal mortality ratio (maternal deaths per 100 000 live births) | 11 (10–161) | 11 (11–15) | 0·0693 | 8 (7·5–8·0) | 8 (7·0–8) | 0·13 |
| Demographics | ||||||
| Race | .. | .. | 0·0259 | Not collected | Not collected | .. |
| White | 379 (34·8%) | 2485 (31·8%) | .. | .. | .. | .. |
| Asian | 323 (29·7%) | 2365 (30·2%) | .. | .. | .. | .. |
| Black | 303 (27·8%) | 2001 (25·6%) | .. | .. | .. | .. |
| Other | 119 (10·9%) | 909 (11·6%) | .. | .. | .. | .. |
| Maternal age at expected date of delivery (years) | 31 (26–35) | 31 (27–36) | 0·0377 | 29 (26–34) | 31 (27–35) | 0·20 |
| Nulliparous | 653 (60·0%) | 4542 (58·1%) | 0·25 | .. | Not collected | .. |
| Multiple pregnancy | 128 (11·8%) | 529 (6·8%) | <0·0001 | Not collected | Not collected | .. |
| Gestational age at eligibility (weeks) | 33·4 (30·0–37·1) | 36·0 (32·0–38·4) | <0·0001 | 35·6 (31·4–38·9) | 37·9 (35·6–39·7) | <0·0001 |
| Past and current medical and obstetrical history | ||||||
| Cigarette smoking | 139 (12·8%) | 1011 (12·9%) | 0·9232 | Not collected | Not collected | .. |
| Chronic hypertension | 146 (13·4%) | 1324 (16·9) | 0·003 | Not collected | Not collected | .. |
| Pre-gestational renal disease | 63 (5·8%) | 520 (6·6%) | 0·30 | Not collected | Not collected | .. |
| Pre-gestational diabetes | 61 (5·6%) | 409 (5·2%) | 0·61 | Not collected | Not collected | .. |
| Gestational diabetes | 75 (6·9%) | 974 (12·5%) | <0·0001 | Not collected | Not collected | .. |
| Symptoms on day of first assessment | ||||||
| Nausea or vomiting | 107 (9·8%) | 443 (5·7%) | <0·0001 | 20 (16·5%) | 175 (6·3%) | <0·0001 |
| Headache or visual disturbance | 406 (37·3%) | 2132 (27·3%) | <0·0001 | 54 (44·6%) | 760 (27·4%) | <0·0001 |
| Right upper quadrant or epigastric pain | 205 (18·8%) | 754 (9·6%) | <0·0001 | 27 (22·3%) | 138 (5·0%) | <0·0001 |
| Chest pain or dyspnoea | 73 (6·7%) | 117 (1·5%) | <0·0001 | 17 (14·1%) | 29 (1·0%) | <0·0001 |
| Signs on day of first assessment | ||||||
| Height (cm) | 162 (157–166) | 163 (157–168) | 0·24 | 164 (160–168) | 165 (161–169·6) | 0·0689 |
| Weight (kg) | 78·0 (68·5–87·0) | 81·0 (70·3–93·4) | <0·0001 | 77·0 (67·5–88) | 85·9 (75–100) | <0·0001 |
| Systolic blood pressure (mm Hg) | 156 (147–166) | 151 (140–161) | <0·0001 | 150 (143–164) | 148 (142–156) | 0·0071 |
| Diastolic blood pressure (mm Hg) | 99 (91–105) | 96 (90–100) | <0·0001 | 94 (90–100) | 94 (90–99) | 0·53 |
| Oxygen saturation less than 93% | 43 (3·9%) | 28 (0·4%) | <0·0001 | Not collected | Not collected | NA |
| Dipstick proteinuria (number of pluses) | 2 (1–3) | 1 (1–2) | <0·0001 | 1 (1–1) | 1 (0–1) | <0·0001 |
| Laboratory tests—worst values on day of first assessment | ||||||
| Haematocrit (%) | 0·36 (0·34–0·38) | 0·36 (0·34–0·38) | 0·0019 | 0·35 (0·32–0·38) | 0·36 (0·33–0·38) | 0·0683 |
| Total leucocyte count (×109 per L) | 10·9 (9·5–12·3) | 10·6 (9·3–12·0) | <0·0002 | 9·66 (7·62–13·57) | 9·9 (8·2–12) | 0·73 |
| Platelet count (×109 per L) | 198 (157–235) | 212 (175–245) | <0·0001 | 189 (126–237) | 219 (182–265) | <0·0001 |
| Mean platelet volume (fL) | 9·6 (8·9–10·8) | 10·0 (9·1–11·2) | <0·0001 | 9·5 (8·7–10·7) | 9·8 (8·9–10·9) | 0·28 |
| Fibrinogen (g/L) | 27·1 (25·1–29·3) | 26·2 (24·6–27·9) | <0·0001 | 6·2 (5·4–7·4) | 6·5 (5·7–7·2) | 0·19 |
| Activated partial thromboplastin time (seconds) | 27·5 (25·5–30·0) | 26·6 (24·8–28·2) | <0·0001 | 26·2 (24·37–28·85) | 26·4 (24·35–27·8) | 0·69 |
| Serum creatinine (μmol/L) | 64 (54–75) | 60 (52–70) | <0·0001 | 61 (50–74·5) | 54 (47–63) | <0·0001 |
| Uric acid (mmol/L) | 365 (321–418) | 339 (297–385) | <0·0001 | 350 (297–435) | 339·5 (281·25–396) | 0·0758 |
| Aspartate transaminase (U/L) | 39 (29–65) | 29 (22–41) | <0·0001 | 28 (22·5–49·5) | 23 (18–31) | <0·0001 |
| Alanine transaminase (U/L) | 32 (20–55) | 23 (14–35) | <0·0001 | 17 (11–33·25) | 14 (10–20) | 0·0183 |
| Albumin (g/L) | 27 (18–30) | 29 (23–32) | <0·0001 | 34 (31–36) | 35 (33–37) | <0·0001 |
| Corticosteroid received | 377 (34·8%) | 1695 (21·8%) | <0·0001 | Not collected | Not collected | .. |
| Antihypertensive medication received | 714 (65·9%) | 4097 (52·7%) | <0·0001 | 53 (43·8%) | 849 (30·6%) | 0·0025 |
| Magnesium sulphate received | 556 (51·3%) | 2257 (29·0%) | <0·0001 | 4 (3·3%) | 15 (0·5%) | 0·0069 |
| Pregnancy outcomes | ||||||
| Gestational age at delivery (weeks) | 35·0 (31·5–37·6) | 37·0 (34·1–38·7) | <0·0001 | 36·4 (32·9–39·4) | 39 (37·3–40·1) | <0·0001 |
| Birthweight (g) | 1900 (965–2750) | 2560 (1556–3200) | <0·0001 | Not collected | Not collected | .. |
| Intrauterine fetal death, ≥22+0 weeks or ≥500 grams22 | 65 (6·0%) | 163 (2·1%) | <0·0001 | 6 (4·96%) | 18 (0·65%) | <0·0003 |
| Neonatal death within 28 days | 40 (3·7%) | 102 (1·3%) | <0·0001 | 2 (1·65%) | 1 (0·04%) | 0·0050 |
Data are n (%) or median (IQR). Race has been defined in the appendix (pp 4–5). NA=not applicable.
*
χ2, Fisher's exact, or Mann-Whitney U test.