Table 1.
Characteristics of the study participants, by hypertensive status, in the Study of Pregnancy Hypertension in Iowa
| Characteristics | PE (n= 238) | GH (n=219) | NT Controlsa (n = 342) | P-value |
|---|---|---|---|---|
| Age group n (%) | ||||
| 18–24 | 86 (36.0) | 79 (36.1) | 100 (29.2) | 0.35 |
| 25–29 | 92 (38.5) | 89 (40.6) | 159 (46.5) | |
| 30–34 | 45 (18.8) | 39 (17.8) | 56 (16.4) | |
| 35–41 | 16 (6.7) | 12 (5.5) | 27 (7.9) | |
| Gestational age (wk) mean (std) | 36.7 (2.9) | 38.7 (1.5) | 39.2 (1.4) | <0.0001 |
| Birth weight (g) mean (std) | 2840.4 (794.6) | 3419.4 (502.9) | 3476.3 (447.0) | <0.0001 |
| BWGA z-score mean (std)b | −0.17 (0.90) | 0.25 (0.90) | 0.18 (0.8) | 0.0004 |
| Race n (%) | ||||
| White | 220 (92.4) | 208 (95.0) | 305 (89.2) | 0.05 |
| Non-white | 18 (7.6) | 11 (5.0) | 37 (10.8) | |
| Body mass indexc n (%) | ||||
| Underweight/Normal | 103 (43.1) | 97 (44.3) | 234 (68.4) | <0.0001 |
| Overweight | 66 (27.6) | 69 (31.5) | 73 (21.4) | |
| Obese | 70 (29.3) | 53 (24.2) | 35 (10.2) | |
| Education n (%) | ||||
| High school graduate or less | 38 (16.0) | 34 (15.5) | 44 (12.9) | 0.0004 |
| Some college | 89 (37.4) | 78 (35.6) | 81 (23.7) | |
| College graduate or higher | 111 (46.6) | 107 (48.9) | 217 (63.5) | |
| Smoking during pregnancy n (%) | ||||
| Never | 192 (80.5) | 166 (75.8) | 290 (84.8) | 0.01 |
| 1st trimester only | 28 (11.8) | 32 (14.6) | 20 (5.6) | |
| 2nd/3rd trimesters | 18 (7.6) | 21 (9.6) | 32 (9.4) | |
Abbreviations: PE, preeclampsia; GH, gestational hypertension; NT, normotensive; BWGA, birth weight for gestational age
a
174 NT controls from Study of Pregnancy Hypertension in Iowa and 168 NT controls from Iowa Health in Pregnancy Study
b
Reference population used in calculation of Z-score birth weight for gestational age from Olsen et al [15]
c
BMI was categorized based on the following clinical cut points: underweight/normal, <25; overweight, 25.0–29.9; obese, ≥ 30 kg/m2