Table 1.
Demographic and clinical characteristics of the population
| PA (N=621) | No PA (N=634) | P | |||
|---|---|---|---|---|---|
| n | % | n | % | ||
| Maternal age (mean (SD)) | 28.7 (6.7) | 28.1 (6.4) | 0.15 | ||
| 18–19 | 39 | 6.3 | 52 | 8.2 | 0.08 |
| 20–29 | 315 | 50.7 | 320 | 50.5 | |
| 30–34 | 124 | 20.0 | 147 | 23.2 | |
| 35+ | 143 | 23.0 | 115 | 18.1 | |
| Pre-pregnancy BMI (mean (SD)) | 24.6 (3.8) | 25.0 (3.9) | 0.08 | ||
| <25 | 362 | 59.7 | 369 | 59.5 | 0.17 |
| 25.0–29.9 | 190 | 31.4 | 177 | 28.6 | |
| 30.0+ | 54 | 8.9 | 74 | 11.9 | |
| Maternal education <12 years | 411 | 66.2 | 473 | 74.6 | 0.0011 |
| Worked while pregnant | 337 | 54.4 | 334 | 52.7 | 0.55 |
| Married/cohabitating | 532 | 86.0 | 554 | 87.4 | 0.45 |
| Major depression (PHQ-9) | 116 | 18.8 | 64 | 10.2 | <0.0001 |
| Fair/poor self-rated pre-pregnancy health | 121 | 19.6 | 89 | 14.1 | 0.0097 |
| Chronic hypertension | 8 | 1.3 | 3 | 0.5 | 0.12 |
| Parity | 0.021 | ||||
| Nulliparous | 285 | 45.9 | 250 | 39.4 | |
| Multiparous | 336 | 54.1 | 384 | 60.6 | |
| No prenatal care | 38 | 6.1 | 17 | 2.7 | 0.0030 |
| Unplanned pregnancy | 376 | 60.7 | 382 | 60.4 | 0.89 |
| Alcohol use in pregnancy | 108 | 17.5 | 114 | 18.0 | 0.80 |
| Cigarette smoking in pregnancy | 10 | 1.6 | 4 | 0.6 | 0.10 |
| Male infant | 345 | 56.1 | 334 | 52.9 | 0.26 |
| First trimester bleeding | 121 | 19.6 | 65 | 10.3 | <0.0001 |
| Previous placental abruption1 | 22 | 5.2 | 1 | 0.2 | <0.0001 |
| Stillbirth | 64 | 10.3 | 1 | 0.2 | <0.0001 |
| Preterm delivery (<37 wk)2 | 340 | 61.0 | 15 | 2.4 | <0.0001 |
| Low birth weight (<2500 g)2 | 277 | 50.3 | 14 | 2.2 | <0.0001 |
| Preeclampsia/eclampsia | 135 | 22.0 | 41 | 6.5 | <0.0001 |
All analyses restricted to singleton births
1
Previous placental abruption among women with prior pregnancies only (n=425 cases, 446 controls).
2
Restricted to live births only (n=557 cases, 633 controls)