Table 4.
Marginal Effects of Other Inputs and Risk Factors on LBW and Preterm birth
| Input/Risk Factor | Group without Birth Defects | Group with Birth Defects | ||
|---|---|---|---|---|
| ME (SE) | % of mean outcome probability | ME (SE) | % of mean outcome probability | |
| LBW (birth weight <2500 grams) | ||||
| Acute illnesses | 0.021** (0.009) | 47.4% | 0.004 (0.017) | 2.1% |
| Miscarriages/stillbirths | 0.013** (0.006) | 30.9% | 0.012 (0.011) | 5.9% |
| Maternal age | -0.005* (0.003) | -12.1% | -0.004 (0.006) | -1.9% |
| Live births | -0.007** (0.003) | -15.6% | -0.017*** (0.005) | -7.9% |
| Varicella immunization | -0.004 (0.017) | -8.7% | -0.068* (0.036) | -32.3% |
| Male | -0.005 (0.008) | -12.4% | -0.042** (0.017) | -19.7% |
| European Latin | -0.009 (0.01) | -21.3% | 0.036* (0.02) | 16.8% |
| European non-Latin | 0.019 (0.018) | 44.4% | -0.052* (0.029) | -24.6% |
| Preterm birth (gestation <37 weeks) | ||||
| Multivitamin | -0.053** (0.021) | -50.3% | -0.009 (0.035) | -3.9% |
| Physical shocks | 0.093** (0.046) | 88.9% | -0.03 (0.037) | -13.4% |
| Maternal education-Less than primary versus primary school | 0.035* (0.021) | 33.7% | 0.017 (0.027) | 7.3% |
| Maternal education-secondary versus primary school | -0.047*** (0.016) | 44.9% | 0.006 (0.027) | 2.6% |
| Maternal age | -0.013** (0.005) | -12.6% | -0.012** (0.006) | -5.3% |
| Acute illnesses | 0.026* (0.013) | 24.9% | 0.039** (0.018) | 17.2% |
| Chronic illnesses | 0.017 (0.017) | 16.4% | 0.066*** (0.022) | 29.2% |
| European non-Latin ancestry | 0.046 (0.028) | 43.5% | -0.058* (0.029) | -25.5% |
| Miscarriages/stillbirths | 0.01 (0.01) | 9.2% | 0.027** (0.011) | 11.8% |
| Pregnancy year 2001 | 0.058 (0.042) | 54.9% | 0.1* (0.054) | 44.0% |
| Pregnancy year 2002 | 0.092 (0.063) | 87.6% | 0.149** (0.07) | 65.7% |
Note: Marginal probability effects (ME) and mean predicted probabilities are estimated holding model covariates at their means. A reduced form probit function was estimated for LBW and preterm birth for each infant group. The inputs and risk factors included above are the ones that had significant coefficients and marginal effects for at least one infant group. The mean predicted probabilities of LBW and preterm birth were 0.044 and 0.105 respectively in group without birth defects, and 0.211 and 0.227 respectively in the group with birth defects. Standard errors (SE) of marginal effects are listed in parentheses.
*, ** and *** indicate significant marginal effects at p<0.1, p<0.05 and p<0.01 respectively.