TABLE 1—
Frequencies and Crude ORs of Demographic and Indoor Air Pollution Variables Among Never Smokers: Environment and Pregnancy Outcomes Study, Los Angeles County, CA, 2003
| Preterm (n = 727), Mean ±SD or No. (%) | Term LBW (n = 159), Mean ±SD or No. (%) | Control (n = 875), Mean ±SD or No. (%) | Preterm Crude OR (95% CI) | Term LBW Crude OR (95% CI) | |
| Birth weight, g | 2839.7 ±763.3 | 2283.4 ±199.0 | 3421.1 ±437.9 | … | … |
| Gestational age, d | 241.7 ±19.8 | 273.8 ±11.6 | 278.3 ±10.4 | … | … |
| Demographic variables | |||||
| Maternal age, y | |||||
| < 20 | 93 (12.8) | 21 (13.2) | 95 (10.9) | 1.21 (0.77, 1.65) | 1.10 (0.55, 1.87) |
| 20–24 | 155 (21.3) | 39 (24.5) | 185 (21.1) | 1.00 (Ref) | 1.00 (Ref) |
| 25–29 | 181 (24.9) | 38 (23.9) | 272 (31.1) | 0.77 (0.55, 1.10) | 0.66 (0.44, 1.10) |
| 30–34 | 189 (26.0) | 42 (26.4) | 215 (24.6) | 1.10 (0.77, 1.43) | 0.88 (0.55, 1.54) |
| ≥ 35 | 109 (15.0) | 19 (11.9) | 108 (12.3) | 1.21 (0.88, 1.65) | 0.88 (0.44, 1.54) |
| Maternal race/ethnicity | |||||
| Non-Hispanic White | 79 (10.9) | 8 (5.0) | 113 (12.9) | 1.00 (Ref) | 1.00 (Ref) |
| Hispanic White | 535 (73.6) | 122 (76.7) | 628 (71.8) | 1.21 (0.88, 1.65) | 2.75 (1.32, 5.72) |
| Black | 51 (7.0) | 13 (8.2) | 48 (5.5) | 1.54 (0.88, 2.53) | 3.85 (1.54, 9.79) |
| Asiana | 26 (3.6) | 9 (5.7) | 49 (5.6) | 0.77 (0.44, 1.32) | 2.64 (0.99, 7.15) |
| Otherb | 32 (4.4) | 7 (4.4) | 31 (3.5) | 1.43 (0.88, 2.64) | 3.19 (1.10, 9.46) |
| Missing | 4 (0.6) | 0 (0.0) | 6 (0.7) | … | … |
| Maternal education, y | |||||
| ≤ 8 | 127 (17.5) | 28 (17.6) | 135 (15.4) | 1.10 (0.77, 1.43) | 1.43 (0.77, 2.42) |
| 9–11 | 171 (23.5) | 39 (24.5) | 202 (23.1) | 0.99 (0.77, 1.21) | 1.32 (0.77, 2.20) |
| 12 | 199 (27.4) | 33 (20.8) | 223 (25.5) | 1.00 (Ref) | 1.00 (Ref) |
| 13–15 | 109 (15.0) | 30 (18.9) | 123 (14.1) | 0.99 (0.77, 1.32) | 1.65 (0.99, 2.86) |
| ≥ 16 | 111 (15.3) | 27 (17.0) | 171 (19.5) | 0.77 (0.55, 0.99) | 1.10 (0.66, 1.87) |
| Missing | 10 (1.4) | 2 (1.3) | 21 (2.4) | … | … |
| Maternal marital status | |||||
| Single, separated, divorced, and widowed | 129 (17.7) | 39 (24.5) | 171 (19.5) | 1.32 (0.99, 1.65) | 1.21 (0.77, 1.76) |
| Living together but not married | 201 (27.6) | 38 (23.9) | 198 (22.6) | 0.99 (0.77, 1.21) | 1.43 (0.88, 2.20) |
| Married | 392 (53.9) | 81 (50.9) | 501 (57.3) | 1.00 (Ref) | 1.00 (Ref) |
| Missing | 5 (0.7) | 1 (0.6) | 5 (0.6) | … | … |
| Payment source for prenatal care | |||||
| Private insurancec | 250 (34.4) | 48 (30.2) | 322 (36.8) | 1.00 (Ref) | 1.00 (Ref) |
| Public insuranced | 465 (64.0) | 110 (69.2) | 541 (61.8) | 1.10 (0.88, 1.32) | 1.32 (0.99, 1.98) |
| No insurance/othere | 12 (1.7) | 1 (0.6) | 9 (1.0) | 1.76 (0.66, 4.18) | 0.77 (0.11, 6.05) |
| Missing | 0 (0.0) | 0 (0.0) | 3 (0.3) | … | … |
| Parity | |||||
| ≥ 1 | 455 (62.6) | 86 (54.1) | 535 (61.1) | 1.00 (Ref) | 1.00 (Ref) |
| 0 | 272 (37.4) | 73 (45.9) | 340 (38.9) | 0.99 (0.77, 1.10) | 1.32 (0.99, 1.87) |
| Maternal birthplace | |||||
| Foreign-born | 487 (67.0) | 101 (63.5) | 585 (66.9) | 0.99 (0.77, 1.21) | 0.88 (0.66, 1.21) |
| US-born | 239 (32.9) | 57 (35.8) | 290 (33.1) | 1.00 (Ref) | 1.00 (Ref) |
| Missing | 1 (0.1) | 1 (0.6) | 0 (0.0) | … | … |
| Maternal birthplace | |||||
| Mexico | 312 (42.9) | 62 (39.0) | 395 (45.1) | 0.99 (0.77, 1.21) | 0.77 (0.55, 1.21) |
| Other (outside US) | 175 (24.1) | 39 (24.5) | 190 (21.7) | 1.10 (0.88, 1.43) | 0.99 (0.66, 1.65) |
| United States | 239 (32.9) | 57 (35.8) | 290 (33.1) | 1.00 (Ref) | 1.00 (Ref) |
| Missing | 1 (0.1) | 1 (0.6) | 0 (0.0) | … | … |
| Mother worked outside the home at any point during pregnancy | |||||
| No | 381 (52.4) | 68 (42.8) | 439 (50.2) | 1.00 (Ref) | 1.00 (Ref) |
| Yes | 344 (47.3) | 89 (56.0) | 430 (49.1) | 0.88 (0.77, 1.10) | 1.32 (0.99, 1.87) |
| Missing | 2 (0.3) | 2 (1.3) | 6 (0.7) | … | … |
| Owned the home in which she lived at any point during pregnancy | |||||
| Own | 165 (22.7) | 40 (25.2) | 210 (24.0) | 1.00 (Ref) | 1.00 (Ref) |
| Rent | 556 (76.5) | 115 (72.3) | 655 (74.9) | 1.10 (0.88, 1.32) | 0.88 (0.66, 1.32) |
| Missing | 6 (0.8) | 4 (2.5) | 10 (1.1) | … | … |
| Annual household income, $ | |||||
| < 40 000 | 451 (62.0) | 95 (59.7) | 537 (61.4) | 1.10 (0.88, 1.43) | 1.10 (0.66, 1.65) |
| ≥ 40 000 | 140 (19.3) | 30 (18.9) | 185 (21.1) | 1.00 (Ref) | 1.00 (Ref) |
| Missing | 136 (18.7) | 34 (21.4) | 153 (17.5) | … | … |
| Health behaviors | |||||
| Prenatal care | |||||
| Began in trimester 1 | 654 (90.0) | 136 (85.5) | 816 (93.3) | 1.00 (Ref) | 1.00 (Ref) |
| Began in trimester 2 or 3 or no prenatal care | 70 (9.6) | 21 (13.2) | 53 (6.1) | 1.65 (1.10, 2.42) | 2.42 (1.43, 4.07) |
| Missing | 3 (0.4) | 2 (1.3) | 6 (0.7) | … | … |
| Lived with ≥ 1 smokers during pregnancy | |||||
| Did not live with smoker | 607 (83.5) | 132 (83.0) | 755 (86.3) | 1.00 (Ref) | 1.00 (Ref) |
| Lived with smoker | 115 (15.8) | 27 (17.0) | 110 (12.6) | 1.32 (0.99, 1.76) | 1.43 (0.88, 2.20) |
| Missing | 5 (0.7) | 0 (0.0) | 10 (1.1) | … | … |
| Used alcohol during pregnancy | |||||
| No | 693 (95.3) | 148 (93.1) | 828 (94.6) | 1.00 (Ref) | 1.00 (Ref) |
| Yes | 32 (4.4) | 11 (6.9) | 46 (5.3) | 0.88 (0.55, 1.32) | 1.32 (0.66, 2.64) |
| Missing | 2 (0.3) | 0 (0.0) | 1 (0.1) | … | … |
Note. CI = confidence interval; LBW = low birth weight; OR = odds ratio. The sample size was n = 1761.
a
Includes Chinese, Japanese, Korean, Vietnamese, Cambodian, Thai, Laotian, Filipino, Indian, and other Asian.
b
Includes Native American, Eskimo, Aleut, Hawaiian, Guamanian, Samoan, Pacific Islanders, and others.
c
Includes private insurance, HMO, and Blue Cross and Blue Shield.
d
Includes Medicare, Medi-Cal, government, and other nongovernment programs.
e
Includes no prenatal care, self-pay, no charge, medically indigent, and other.