Table 1. Characteristics of the Cohort at the Time of the Index Pregnancy.
| Characteristic | No. (%) of participants | P valuea | |
|---|---|---|---|
| Unexposed to LEA (n = 38 176) | Exposed to LEA (n = 109 719) | ||
| Maternal characteristics | |||
| Age at delivery, mean (SD), y | 30.6 (5.5) | 29.8 (5.6) | <.001 |
| Race/ethnicity | |||
| Non-Hispanic White | 8292 (21.7) | 29 149 (26.6) | <.001 |
| Non-Hispanic Black | 2749 (7.2) | 8231 (7.5) | |
| Hispanic | 21 591 (56.6) | 53 878 (49.1) | |
| Asian or Pacific Islanders | 4679 (12.3) | 15 546 (14.2) | |
| Other | 865 (2.3) | 2915 (2.7) | |
| Parity | |||
| 0 | 8821 (23.1) | 39 362 (35.9) | <.001 |
| 1 | 13 293 (34.8) | 33 891 (30.9) | |
| ≥2 | 13 349 (35) | 22 962 (20.9) | |
| Unknown | 2713 (7.1) | 13 504 (12.3) | |
| Educational level | |||
| ≤High school | 13 152 (34.5) | 31 995 (29.2) | <.001 |
| Some college | 10 988 (28.8) | 34 343 (31.3) | |
| College and postgraduate | 13 547 (35.5) | 42 108 (38.4) | |
| Unknown | 489 (1.3) | 1273 (1.2) | |
| Household income, $ | |||
| <30 000 | 1116 (2.9) | 2457 (2.2) | <.001 |
| 30 000-49 999 | 10 453 (27.4) | 25 233 (23) | |
| 50 000-69 999 | 12 787 (33.5) | 35 652 (32.5) | |
| 70 000-89 999 | 7835 (20.5) | 24 884 (22.7) | |
| ≥90 000 | 5985 (15.7) | 21 493 (19.6) | |
| History of comorbidity | 5498 (14.4) | 19 056 (17.4) | <.001 |
| Diabetes during pregnancy | |||
| Gestational diabetes | 3172 (8.3) | 8663 (7.9) | <.001 |
| Pregestational diabetes | 726 (1.9) | 2934 (2.6) | |
| Smoking during pregnancy | 188 (0.5) | 939 (0.9) | <.001 |
| Preeclampsia or eclampsia | 823 (2.2) | 3777 (3.4) | <.001 |
| Prepregnancy BMI, mean (SD) | 26.1 (5.7) | 26.4 (5.9) | <.001 |
| Gestational weight gain, mean (SD), kg | 11.7 (6.1) | 12.5 (6.3) | <.001 |
| Fever during labor | 510 (1.3) | 13 055 (11.9) | <.001 |
| Child characteristics | |||
| Birth weight, mean (SD), g | 3316.2 (495.3) | 3354.5 (475.7) | <.001 |
| Gestational age at delivery, mean (SD), wk | 38.7 (1.6) | 38.9 (1.5) | <.001 |
| Presence of any birth defect | 4447 (11.6) | 14 159 (12.9) | <.001 |
| Female | 19 031 (49.9) | 54 439 (49.6) | .43 |
Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); LEA, labor epidural analgesia.
a
Calculated from χ2 test for categorical variables and from analysis of variance F test for continuous variables.