Table 7 Odd ratios from multiple logistic regression analysis showing predictive factors for birth defects among 260,722 Chinese perinatal infants
Characteristics | aOR | 95%CI | P value |
|---|---|---|---|
Ethnic group | |||
Zhuang | 0.86 | 0.81~0.91 | < 0.0001 |
Miao | 0.56 | 0.50~0.63 | < 0.0001 |
Dong | 0.52 | 0.46~0.60 | < 0.0001 |
Yao | 0.64 | 0.53~0.78 | < 0.0001 |
Han (ref) | 1.00 | ||
Mother’s age | |||
< 20 years | 0.82 | 0.70~0.97 | 0.0371 |
20~24 years | 0.81 | 0.73~0.90 | < 0.0001 |
25~29 year | 0.87 | 0.79~0.96 | 0.0037 |
30~34 years | 0.91 | 0.82~1.00 | 0.0577 |
35 years or above | 1.00 | ||
RPR test for syphilis infection | |||
Positive | 1.42 | 1.05~1.93 | 0.0229 |
Negative (ref) | 1.00 | ||
Gestational age (weeks) | |||
Less than 34 | 9.82 | 8.93~10.80 | < 0.0001 |
34~36 | 2.50 | 2.27~2.75 | < 0.0001 |
37 weeks or more (ref) | 1.00 | ||
Number of antenatal care visits | |||
< 4 times | 1.02 | 0.93~1.11 | 0.7182 |
5~8 times | 0.82 | 0.76~0.90 | < 0.0001 |
9~11 times | 0.76 | 0.70~0.83 | < 0.0001 |
12 times or more (ref) | 1.00 | ||
Gestational age at first antenatal care visit | |||
≤ 9 weeks | 1.00 | 0.90~1.10 | 0.9789 |
10~14 weeks | 0.98 | 0.88~1.10 | 0.7984 |
≥ 15 weeks | |||
Number of previous miscarriages/spontaneous abortions38,39 | |||
< 3 times | 0.48 | 0.22~1.05 | 0.0647 |
4~7 times | 0.35 | 0.15~0.78 | 0.0100 |
8 times or more (ref) | 1.00 | ||
Gender of perinatal infants | |||
Male | 1.27 | 1.20~1.35 | < 0.0001 |
Female (ref) | 1.00 | ||