Table 4.
Indirect and total effects of socioeconomic status and maternal characteristics and lifestyles during pregnancy on SGA
| Pathway | SES→mediators | Mediators→birth outcomes |
B | SE | 95% CI | P values | ß |
| a | b | a*b | |||||
| Small-for-gestational-age (SGA) | |||||||
| Total effect | −0.067 | −0.030 | |||||
| Direct effect (c) | −0.046 | 0.044 | (−0.132 to 0.040) | 0.299 | −0.034 | ||
| Indirect effect | −0.067 | 0.021 | (−0.108 to -0.026) | 0.001 | −0.030 | ||
| SES→Prepregnancy BMI≥18.50→GWG not below IOM recommendations |
0.033*, −0.253** | 0.321** | −0.003 | 0.001 | (−0.005 to -0.001) | 0.007 | −0.001 |
| SES→GWG not below IOM recommendations | −0.045 | 0.321** | −0.014 | 0.013 | (−0.039 to 0.011) | 0.273 | −0.006 |
| SES→Prepregnancy BMI≥18.50 | 0.033* | −0.274** | −0.009 | 0.003 | (−0.015 to -0.003) | 0.010 | −0.004 |
| SES→a multivitamin supplement during the first trimester of pregnancy | 0.317** | −0.066* | −0.021 | 0.008 | (−0.037 to -0.005) | 0.010 | −0.009 |
| SES→Physical activity during the last trimester of pregnancy | 0.284** | 0.017 | 0.005 | 0.003 | (−0.001 to 0.011) | 0.063 | 0.002 |
| SES→Sleep quality in the month before the birth |
0.150** | 0.027 | 0.004 | 0.004 | (−0.004 to 0.012) | 0.297 | 0.002 |
| SES→PIH | −0.176* | 0.166** | −0.029 | 0.013 | (−0.054 to -0.004) | 0.021 | −0.013 |
| Goodness-of-fit | RMSEA=0.012, CFI=0.967 | ||||||
Covariates of maternal age, passive smoking during pregnancy were adjusted for SGA.
*P<0.05; **P<0.001.
BMI, body mass index; CFI, comparative fit index; GWG, gestational weight gain; IOM, Institute of Medicine; PIH, pregnancy-induced hypertension syndrome; RMSEA, the root mean square error of approximation; SES, socioeconomic status.