Table 1.
Descriptive characteristics (percentages)1 of preeclampsia cases and their referent population (controls), California, 1998–2011
| Characteristic | Preeclampsia Phenotypes
|
|||
|---|---|---|---|---|
| CASES | CONTROLS2 | |||
|
|
||||
| Superimposed n=1045 |
Severe n=3471 |
Mild n=2780 |
37–41 weeks n=197,461 |
|
| Maternal age (years) | ||||
| <20 | 2.8 | 16.9 | 17.2 | 14.2 |
| 20–24 | 16.5 | 27.4 | 26.5 | 29.9 |
| 25–29 | 23.4 | 23.7 | 24.0 | 28.0 |
| 30–34 | 29.5 | 17.8 | 18.0 | 18.4 |
| >35 | 27.9 | 14.2 | 14.2 | 9.5 |
| Missing | 0 | 0 | <0.1 | <0.1 |
| Maternal race/ethnicity | ||||
| White, nonHispanic | 25.2 | 25.0 | 28.6 | 29.4 |
| White, Hispanic | 51.9 | 59.7 | 56.7 | 57.0 |
| Black | 12.3 | 5.9 | 6.4 | 4.5 |
| Asian | 7.2 | 6.2 | 6.0 | 7.1 |
| Other | 2.4 | 2.4 | 1.6 | 1.5 |
| Missing | 1.1 | 0.8 | 0.8 | 0.6 |
| Maternal education | ||||
| Less than high school | 24.3 | 28.9 | 28.6 | 32.6 |
| High school | 29.8 | 31.7 | 33.0 | 31.8 |
| More than high school | 43.8 | 37.0 | 36.4 | 34.0 |
| Missing | 2.1 | 2.4 | 2.0 | 1.6 |
| Prenatal care initiation by fifth month of gestation | ||||
| Yes | 89.8 | 89.6 | 90.5 | 91.8 |
| No | 7.5 | 7.1 | 6.5 | 6.4 |
| Missing | 2.8 | 3.3 | 3.0 | 1.8 |
| Parity | ||||
| 1 | 32.3 | 56.4 | 52.5 | 34.8 |
| ≥2 | 67.7 | 43.4 | 47.4 | 65.2 |
| Missing | 0.1 | 0.1 | 0.1 | 0.1 |
| Payer type for delivery | ||||
| Medi-Cal | 55.1 | 56.9 | 58.4 | 56.9 |
| Private | 41.2 | 38.7 | 38.3 | 39.7 |
| Uninsured | 2.9 | 3.1 | 1.9 | 1.7 |
| Other | 0.7 | 1.1 | 1.1 | 1.5 |
| Missing | 0.2 | 0.2 | 0.3 | 0.2 |
| Infant sex | ||||
| Male | 48.9 | 51.8 | 53.1 | 50.6 |
| Female | 51.1 | 48.2 | 46.8 | 49.4 |
| Missing | 0 | 0 | <0.1 | <0.1 |
| Infant Birth Year | ||||
| 1998 | 3.1 | 4.9 | 6.9 | 6.7 |
| 1999 | 3.2 | 4.7 | 6.2 | 6.7 |
| 2000 | 2.6 | 5.5 | 5.8 | 6.9 |
| 2001 | 2.6 | 5.3 | 5.2 | 6.9 |
| 2002 | 5.0 | 5.5 | 6.5 | 7.1 |
| 2003 | 5.2 | 6.8 | 5.9 | 7.4 |
| 2004 | 7.0 | 6.5 | 7.7 | 7.9 |
| 2005 | 6.8 | 7.1 | 8.4 | 9.1 |
| 2006 | 7.0 | 7.4 | 8.2 | 9.5 |
| 2007 | 10.7 | 9.0 | 9.1 | 6.8 |
| 2008 | 10.2 | 8.4 | 8.0 | 6.7 |
| 2009 | 10.8 | 9.6 | 7.8 | 6.3 |
| 2010 | 12.7 | 10.3 | 7.5 | 6.1 |
| 2011 | 13.2 | 9.0 | 6.7 | 6.0 |
| Years 2007–2011 | 603 | 1609 | 1086 | 63021 |
| Prepregnancy body mass index (kg/m2) (2007–2011) | ||||
| Underweight (BMI<18.5) | 0.8 | 1.3 | 2.1 | 3.1 |
| Normal (18.5≤BMI<25) | 14.6 | 30.5 | 27.0 | 40.2 |
| Overweight (25≤BMI<30) | 23.6 | 24.6 | 22.5 | 24.7 |
| Obese (BMI≥30) | 48.8 | 31.5 | 32.7 | 20.3 |
| Missing | 12.3 | 12.1 | 15.8 | 11.8 |
| Poverty (2007–2011) 3 | ||||
| ≤107.25 | 20.9 | 20.2 | 16.0 | 19.4 |
| 107.26 – ≤180.14 | 17.9 | 19.5 | 20.2 | 19.4 |
| 180.15 – ≤260.29 | 19.6 | 17.6 | 17.9 | 19.5 |
| 260.30 – ≤365.66 | 19.1 | 20.9 | 23.3 | 19.6 |
| >365.66 | 20.4 | 19.3 | 20.4 | 19.3 |
| Missing | 2.2 | 2.5 | 2.3 | 2.7 |
1
Percentages may not equal 100 owing to rounding
2
Defined as women who delivered in the study period who did not have diabetes (gestational or pre-existing), did not have any hypertensive disorder, and delivered at 37 weeks or greater.
3
Quintile cutoffs were determined among term births. The highest quintile reflects the highest degree of poverty.