Table 1. Characteristics of Individuals Who Delivered a Singleton Live Birth or Stillbirth by Exposure to Implementation of a Multimodal Prenatal Health Care Model During the COVID-19 Pandemic at Kaiser Permanente Northern California, 2018-2021.
| Characteristic | Patients, No. (%) (N = 151 464) | Standardized mean difference | |||
|---|---|---|---|---|---|
| Unexposed (T1) (n = 75 836) | Partially exposed (T2) (n = 34 799) | Fully exposed (T3) (n = 40 829) | T2 vs T1 | T3 vs T1 | |
| Age, y | |||||
| mean (SD) | 31.23 (5.3) | 31.40 (5.2) | 31.49 (5.2) | 0.032 | 0.049 |
| <25 | 8559 (11.3) | 3640 (10.5) | 4107 (10.1) | −0.027 | −0.040 |
| 25-29 | 18 653 (24.6) | 8261 (23.7) | 9613 (23.5) | −0.020 | −0.025 |
| 30-34 | 27 520 (36.3) | 12 854 (36.9) | 15 278 (37.4) | 0.013 | 0.023 |
| 35-54 | 21 100 (27.8) | 10 042 (28.9) | 11 828 (29.0) | 0.023 | 0.025 |
| Missing | 4 (<.01) | 2 (<.01) | 3 (<.01) | NA | NA |
| Race and ethnicity | |||||
| American Indian and Alaska Native | 282 (0.4) | 119 (0.3) | 156 (0.4) | −0.005 | 0.002 |
| Asian and Pacific Islander | 19 799 (26.1) | 8947 (25.7) | 10 368 (25.4) | −0.009 | −0.016 |
| Black | 4978 (6.6) | 2306 (6.7) | 2729 (6.7) | 0.003 | 0.005 |
| Hispanic | 20 761 (27.4) | 9826 (28.2) | 11 658 (28.6) | 0.019 | 0.026 |
| Multiracial | 2019 (2.6) | 883 (2.6) | 1030 (2.6) | −0.008 | −0.009 |
| White | 26 388 (34.8) | 11 866 (34.1) | 13 875 (34.0) | −0.015 | −0.017 |
| Missing | 1609 (2.1) | 852 (2.4) | 1013 (2.5) | 0.022 | 0.024 |
| Neighborhood Deprivation Index, quartile | |||||
| 1 | 20 986 (27.7) | 9945 (28.6) | 11 526 (28.2) | 0.020 | 0.012 |
| 2 | 17 808 (23.5) | 8332 (23.9) | 9849 (24.1) | 0.011 | 0.015 |
| 3 | 18 829 (24.8) | 8115 (23.3) | 9682 (23.7) | −0.035 | −0.026 |
| 4 | 18 135 (23.9) | 8367 (24.0) | 9665 (23.7) | 0.003 | −0.006 |
| Missing | 78 (0.1) | 40 (0.1) | 107 (0.3) | 0.004 | 0.037 |
| Residing in a neighborhood with mean education level <12 grades | 13.38 (10.3) | 13.50 (10.4) | 13.38 (10.3) | 0.011 | 0.000 |
| Parity | |||||
| 0 | 32 895 (43.4) | 15 089 (43.4) | 17 411 (42.6) | 0.000 | −0.015 |
| 1 | 26 260 (34.6) | 12 021 (34.5) | 14 215 (34.8) | −0.002 | 0.004 |
| ≥2 | 16 120 (21.3) | 7329 (21.1) | 8578 (21.0) | −0.005 | −0.006 |
| Missing | 561 (0.7) | 360 (1.0) | 625 (1.5) | 0.031 | 0.075 |
| Pregestational diabetes | 793 (1.0) | 465 (1.3) | 512 (1.3) | 0.027 | 0.020 |
| Chronic hypertension | 3961 (5.2) | 1943 (5.6) | 2534 (6.2) | 0.016 | 0.042 |
| Prepregnancy body mass indexa | |||||
| Underweight | 6344 (8.4) | 2823 (8.1) | 3179 (7.8) | −0.009 | −0.021 |
| Normal weight | 26 049 (34.3) | 11 523 (33.1) | 13 269 (32.5) | −0.026 | −0.039 |
| Overweight | 20 950 (27.6) | 9672 (27.8) | 11 548 (28.3) | 0.004 | 0.015 |
| Obese | 20 250 (26.7) | 9751 (28.0) | 11 745 (28.8) | 0.030 | 0.046 |
| Missing | 2243 (3.0) | 1030 (3.0) | 1088 (2.7) | 0.000 | −0.018 |
| Singleton birth | 74 635 (98.4) | 34 290 (98.5) | 40 285 (98.7) | 0.010 | 0.021 |
| Infant sex | |||||
| Female | 34 898 (46.0) | 16 169 (46.5) | 18 840 (46.1) | 0.009 | 0.003 |
| Male | 36 814 (48.5) | 16 880 (48.5) | 19 941 (48.8) | −0.001 | 0.006 |
| Missing | 4124 (5.4) | 1750 (5.0) | 2048 (5.0) | −0.018 | −0.019 |
| Gestational age at delivery, mean (SD), wk | 38.67 (2.14) | 38.65 (2.10) | 38.58 (2.17) | −0.009 | −0.039 |
| <22 | 146 (0.2) | 67 (0.2) | 91 (0.2) | 0.000 | 0.007 |
| 22-31 | 945 (1.2) | 385 (1.1) | 543 (1.3) | −0.013 | 0.007 |
| 32-33 | 619 (0.8) | 303 (0.9) | 335 (0.8) | 0.006 | 0.000 |
| 34-36 | 4345 (5.7) | 2043 (5.9) | 2362 (5.8) | 0.006 | 0.002 |
| ≥37 | 69 781 (92.0) | 32 001 (92.0) | 37 498 (91.8) | −0.002 | −0.006 |
| Smoking during pregnancy | |||||
| Never | 73 684 (97.2) | 33 970 (97.6) | 40 128 (98.3) | 0.029 | 0.075 |
| Ever | 1420 (1.9) | 533 (1.5) | 386 (0.9) | −0.026 | −0.079 |
| Missing | 732 (1.0) | 296 (0.9) | 315 (0.8) | −0.012 | −0.021 |
| Medicaid enrollment | 8082 (10.7) | 3746 (10.8) | 4575 (11.2) | 0.003 | 0.018 |
| Pregnancy delivered at Kaiser Permanente Northern California hospital | 71 916 (94.8) | 33 113 (95.2) | 38 891 (95.3) | 0.015 | 0.019 |
Abbreviations: NA, not available; T1, birth delivery between July 1, 2018, and February 29, 2020; T2, birth delivery between March 1, 2020, and December 5, 2020; T3, birth delivery between December 6, 2020, and October 31, 2021.
a
Prepregnancy body mass index (calculated as weight in kilograms divided by height in meters squared) was categorized according to the World Health Organization recommendations on specific body mass index cutoffs for individuals of different races and ethnicities: non-Asian women (underweight, <18.5; normal weight, 18.5-24.9; overweight, 25.0-29.9; obese, 30.0); and Asian women (underweight, <18.5; normal weight, 18.5-22.9; overweight, 23.0-27.4; and obese, ≥27.5).20