Table 1.
Age-standardized characteristics of Nurses’ Health Study II participants by hypertensive status at first pregnancy
| Hypertensive Disorder in First Pregnancy Status | |||
|---|---|---|---|
| Normotensive Pregnancy n=54,756 (90.7%) | Gestational Hypertension n=1,789 (3.0%) | Preeclampsia n=3,834 (6.4%) | |
|
| |||
| Age at first birth, years, mean (SD)* | 27.0 (4.6) | 28.2 (4.9) | 27.0 (4.8) |
| Age at NHSII enrollment (1989), years, mean (SD)* | 35.1 (4.7) | 34.3 (4.7) | 34.5 (4.6) |
| Nulliparous at NHSII enrollment | 16 | 18 | 16 |
| Race/ethnicity | |||
| White | 94 | 95 | 94 |
| Black | 1 | 1 | 1 |
| Hispanic/Latina | 2 | 1 | 2 |
| Asian | 1 | 1 | 1 |
| Other/Multi-racial | 2 | 2 | 2 |
| Participant mother’s years of education >12 years | 32 | 32 | 32 |
| Participant father’s years of education >12 years | 38 | 35 | 38 |
| Strenuous physical activity, at ages 18–22 years | |||
| Never | 28 | 29 | 27 |
| 10–12 months/year | 11 | 11 | 11 |
| Pre-pregnancy body mass index, kg/m2, mean (SD) | 21.8 (3.5) | 23.3 (4.4) | 22.9 (4.2) |
| Pre-pregnancy body mass index ≥30 kg/m2 | 2 | 7 | 6 |
| Pre-pregnancy type 2 diabetes mellitus† | <1 | 0 | 0 |
| Pre-pregnancy hypercholesterolemia | 3 | 3 | 4 |
| Parental history of MI/fatal CAD or stroke before age 60 | 20 | 24 | 24 |
| Alternative Healthy Eating Index (AHEI) score‡ | |||
| Lowest quintile (unhealthy) | 20 | 23 | 22 |
| Highest quintile (healthy) | 19 | 20 | 18 |
| Pre-pregnancy smoking status | |||
| Never | 68 | 70 | 68 |
| Past | 10 | 9 | 10 |
| Current | 22 | 21 | 22 |
| Pre-pregnancy alcohol intake | |||
| None | 26 | 27 | 28 |
| ≤1 drink/week | 37 | 36 | 36 |
| 2–6 drinks/week | 29 | 29 | 28 |
| ≥1 drink/day | 8 | 8 | 8 |
| Pre-pregnancy oral contraceptive use | |||
| Never | 22 | 21 | 19 |
| <2 years | 25 | 26 | 27 |
| 2–<4 years | 22 | 21 | 22 |
| ≥4 years | 31 | 32 | 32 |
| Preterm delivery (<37 weeks) in first birth | 8 | 8 | 16 |
| Final parity§ | |||
| 1 birth | 16 | 21 | 22 |
| 2 births | 49 | 48 | 49 |
| 3 births | 26 | 23 | 23 |
| ≥4 births | 9 | 8 | 7 |
Percentages unless otherwise noted. Values are means (SD) or percentages and are standardized to the age distribution of the study population. Values of polytomous variables may not sum to 100% due to rounding.
Information for above characteristics was missing in n=6,934 for participant mother’s education, n=7,689 for participant father’s education, n=352 for pre-pregnancy smoking, n=351 for strenuous physical activity at 18–22 y, n=255 for pre-pregnancy alcohol intake, n=27,460 for AHEI diet score, and n=974 for pre-pregnancy oral contraceptive use
Value is not age adjusted
n=11 women (0.02%) developed type 2 diabetes mellitus prior to first pregnancy (all of whom had a normotensive first pregnancy)
Self-reported diet based on high school diet information (for women with first birth before 1991) or within 0–3 years before first birth if first birth was in 1991 or later
Final parity based on self-reported lifetime pregnancy history provided on the 2009 biennial questionnaire