Table 1.
Characteristics of Participants in the Combined Training and Tuning Sets and in the Three Test Sets.*
| Training and Tuning Sets (n=3509) |
Main Test Set (n=716) |
IVF Test Set, North Carolina (n=47) | Novice Test Set, Zambia (n=249) | |||
|---|---|---|---|---|---|---|
| Characteristic† | North Carolina (n=854) | Zambia (n=2655) | North Carolina (n=360) | Zambia (n=356) | ||
| Age — yr | 30 (26 to 33) | 27 (23 to 32) | 30 (27 to 34) | 27 (24 to 31) | 37 (33 to 39) | 27 (23 to 30) |
|
| ||||||
| BMI‡ | 25.3 (22.1 to 29.2) | 24.5 (21.8 to 28.3) | 25.2 (22.0 to 29.5) | 24.6 (22.1 to 29.0) | 24.6 (22.7 to 28.1) | 24.2 (21.8 to 27.2) |
|
| ||||||
| <18.5 | 14 (1.6) | 97 (3.7) | 7 (1.9) | 11 (3.1) | 1 (2.1) | 7 (2.8) |
|
| ||||||
| 18.5 to 30 | 553 (64.8) | 1998 (75.3) | 234 (65.0) | 258 (72.5) | 34 (72.3) | 199 (79.9) |
|
| ||||||
| >30 | 163 (19.1) | 454 (17.1) | 74 (20.6) | 72 (20.2) | 7 (14.9) | 22 (8.9) |
|
| ||||||
| Parity | 2.0 (1.0 to 3.0) | 3.0 (2.0 to 4.0) | 2.0 (1.0 to 3.0) | 3.0 (2.0 to 4.0) | 2 (1 to 4) | 2 (2 to 4) |
|
| ||||||
| Gestational age at dating ultrasound — wk | 9.0 (8.0 to 11.6) | 26.3 (20.5 to 31.4) | 8.9 (7.7 to 11.0) | 23.9 (19.4 to 27.6) | NA§ | 23.7 (19.8 to 27.4) |
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| ||||||
| No. of studies contributed | 1 (1 to 11) | 1 (1 to 7) | 1 (1 to 11) | 1 (1 to 5) | 1 (1 to 5) | 1 (1 to 5) |
|
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| Chronic hypertension¶ | 30 (3.5) | 165 (6.2) | 16 (4.4) | 19 (5.3) | 0 (0) | 11 (4.4) |
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| Diabetes‖ | 43 (5.0) | 17 (0.6) | 22 (6.1) | 1 (0.3) | 6 (12.8) | 3 (1.2) |
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| HIV infection | 2 (0.2) | 719 (27.1) | 3 (0.8) | 137 (38.5) | 0 (0) | 38 (15.3) |
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| Syphilis in pregnancy | 3 (0.4) | 78 (2.9) | 1 (0.3) | 22 (6.2) | 0 (0) | 7 (2.8) |
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| Asthma** | 145 (17.0) | 49 (1.8) | 48 (13.3) | 11 (3.1) | 8 (17.0) | 3 (1.2) |
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| Tuberculosis | 0 (0) | 80 (3.0) | 1 (0.3) | 13 (3.7) | 0 (0) | 2 (0.8) |
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| Alcohol use during pregnancy | 196 (23.0) | 220 (8.3) | 89 (24.7) | 57 (16.0) | 13 (27.7) | 17 (6.8) |
|
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| Tobacco use during pregnancy | 68 (8.0) | 6 (0.2) | 33 (9.2) | 4 (1.1) | 0 (0) | 0 (0) |
|
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| Pregnancy conceived by IVF | 2 (0.2)†† | 0 (0) | 0 (0) | 0 (0) | 47 (100) | 0 (0) |
Data are presented as median (interquartile range) or n (%). HIV denotes human immunodeficiency virus, IVF in vitro fertilization.
Information on medical conditions was obtained from both patient interview and medical record review.
The body-mass index (BMI) is the weight in kilograms divided by the square of the height in meters. Missing height prevents BMI calculation of 5 in the IVF test set, 21 in the novice test set, 60 in the main test set, and 230 in the combined training sets.
NA denotes not applicable because gestational age was assigned by known fertilization date in the IVF test set.
Chronic hypertension is defined as ever having a diagnosis of hypertension outside of pregnancy or a new diagnosis in the current pregnancy prior to 20 weeks of gestation.
Diabetes includes both pregestational and gestational diabetes.
Asthma is defined as ever having received the diagnosis of asthma.
Two women who conceived by IVF had blind sweeps collected with the Butterfly iQ device but not a commercial ultrasound machine; hence, they were not able to be included in the IVF test set.