Table 1.
Characteristics of Study Population
| Randomized Group☆ | ||
|---|---|---|
| Characteristic | 1-step | 2-step |
| n=11922 | n=11870 | |
| Maternal Age in years: Mean (SD) | 29.4 (5.5) | 29.3 (5.5) |
| Body Mass Index at 1st prenatal visit: mean (SD) † | 27.4 (6.7) | 27.6 (7.0) |
| Pre-pregnancy Obesity† (BMI≥30 kg/m2): n (%) | 2527 (26.6) | 2615 (27.7) |
| Medicaid: n (%) | 1914 (16.1) | 1810 (15.3) |
| Race/Ethnicity: n (%) ‡ | ||
| Caucasian | 6608 (55.4) | 6586 (55.5) |
| Asian | 1789 (15.0) | 1782 (15.0) |
| Native Hawaiian/Pacific Islander | 623 (5.2) | 619 (5.2) |
| Black | 329 (2.8) | 328 (2.8) |
| American Indian | 49 (0.4) | 50 (0.4) |
| Multiple Races | 1317 (11.1) | 1310 (11.0) |
| Other | 40 (0.3) | 42 (0.4) |
| Unknown | 1167 (9.8) | 1153 (9.7) |
| Study Site Region: n (%) | ||
| Northwest | 8203 (68.8) | 8140 (68.6) |
| Hawaii | 3719 (31.2) | 3730 (31.4) |
| Nulliparous: n (%) | 3642 (30.6) | 3616 (30.5) |
| Prior Hypertension: n (%) | 948 (8.0) | 976 (8.2) |
| Prior GDM: n (%) | 636 (5.3) | 637 (5.4) |
| Gestational Weight Gain exceeding NAM guidelines: n (%) § | 4160 (45.0) | 4255 (46.6) |
Randomized Group - compares pregnancies randomized to 1-step vs those randomized to 2-step
BMI was assessed at first OB visit (mean gestation = 10.9 weeks); six pregnancies did not have these measurements; Pre-pregnancy obesity is BMI≥30kg/m2 based on weight. Pre-pregnancy weight was most recent pre-pregnancy weight measurement up to 3 months prior to estimated date of conception, or (if not available) the earliest weight measurement during pregnancy (up to 12 weeks of gestation)
Hispanic ethnicity was reported for 11,859 pregnancies (49.8%); 1,343 (22.4%) pregnancies randomized to 1-step and 1,280 (21.8%) pregnancies randomized to 2-step reported Hispanic ethnicity
5420 patients were missing either pre-pregnancy weight or weight at delivery needed to calculate this measure