Table 1.
Description and distribution of primary maternal characteristics
| Variable | Definition | Mean or % | ||
|---|---|---|---|---|
| Total sample (N=1774) | African ancestry (N=740) | No African ancestry (N=1034) | ||
| Multivitamin | Indicator (0,1) for any use of multivitamin/prenatal vitamin during pregnancy (%) | 13.9 | 13.6 | 14.0 |
| Multivitamin in first trimester | Indicator (0,1) for any use of multivitamin/prenatal vitamin during first trimester of pregnancy (%) | 7.4 | 7.4 | 7.4 |
| Folic acid in first trimester | Indicator (0,1) for any use of folic acid containing supplements during first trimester of pregnancy (%) | 8.9 | 9.1 | 8.8 |
| Birth defect history | Indicator (0,1) for reporting any child relatives with cleft lip and palate, congenital heart disease, neural tube defects, Down syndrome, or polydactyly (%) | 6.1 | 5.9 | 6.2 |
| Difficulty in conception | Indicator (0,1) for reporting difficulty in conception (%) | 12.3 | 11.8 | 12.7 |
| Acute illness | Indicator (0,1) for acute illnesses during pregnancy (%) | 47.1 | 44.5* | 49.0* |
| Chronic illness | Indicator (0,1) for any chronic illnesses during pregnancy (%) | 17.5 | 18.5 | 16.7 |
| First trimester bleeding | Indicator (0,1) for vaginal bleeding in 1st trimester (%) | 8.2 | 8.2 | 8.1 |
| Live births | Number of live births prior to birth of sampled subject | 1.3 (1.5) | 1.4* (1.6) | 1.3* (1.4) |
| Miscarriages/stillbirths | Number of miscarriages and stillbirths prior to sampled subject | 0.3 (0.7) | 0.3 (0.7) | 0.3 (0.7) |
| Maternal age 26-35 a | Indicator (0,1) for maternal age between 26 and 35 years inclusive (%) | 45.1 | 46.9 | 43.8 |
| Maternal age ≥36a | Indicator (0,1) for maternal age of 36 years or older (%) | 11.8 | 10.8 | 12.5 |
| Prenatal visits | Number of obtained prenatal visits | 7.1 (3.0) | 6.6 (2.4) | 7.2 (2.9) |
| Prenatal ultrasounds | Number of ultrasound examinations obtained during pregnancy | 2.1 (1.5) | 2.1 (1.6) | 2.1 (1.5) |
| Maternal education-Less than primary b | Indicator (0,1) for below primary school education (%) | 44.8 | 48.5*** | 42.1*** |
| Maternal education-Incomplete secondary b | Indicator (0,1) for incomplete secondary school education (%) | 11.7 | 11.2 | 12.0 |
| Maternal education-Secondary b | Indicator (0,1) for secondary school education (%) | 19.6 | 19.3 | 19.7 |
| Maternal education-University b | Indicator (0,1) for university education (%) | 9.0 | 7.7 | 10.0 |
Note: Standard Deviations are listed in parentheses;
a
Reference category is maternal age between 20 and 25 years of age inclusive;
b
Reference category is completed primary school;
* and *** indicate significant differences by African ancestry at p<0.1 and <0.01 respectively.