Table 1.
Means and Standard Deviations of Study Variables
| Variable name | Definition | Infants without Birth Defects (N=2325) | Infants with Birth Defects (N=2417) |
|---|---|---|---|
| Infant Health Outcomes | |||
| Low birth weight | Indicator (0,1) for low birth weight (<2500 grams) | 0.061*** (0.239) | 0.226 (0.418) |
| Preterm Birth | Indicator (0,1) for gestational age <37 weeks | 0.129*** (0.336) | 0.252 (0.434) |
| Prenatal Care Measures | |||
| Weeks | Pregnancy weeks elapsed prior to initiating prenatal care | 17.102 (9.188) | 17.054 (9.556) |
| Other Health Inputs | |||
| Multivitamin | Indicator (0,1) for multivitamin use during pregnancy | 0.054 (0.226) | 0.065 (0.246) |
| Tetanus | Indicator (0,1) for tetanus immunization in 1st trimester | 0.053 (0.225) | 0.046 (0.208) |
| Varicella | Indicator (0,1) for varicella immunization in 1st trimester | 0.092* (0.289) | 0.077 (0.266) |
| Physical shocks | Indicator (0,1) for maternal exposure to physical factors in 1st trimester | 0.033*** (0.179) | 0.055 (0.228) |
| Risk Indicators (also potential health determinants) | |||
| Birth defect history | Indicator (0,1) for reporting any relatives of the child with the studied birth defects | 0.061*** (0.240) | 0.183 (0.387) |
| Difficulty in conception | Indicator (0,1) for reporting any difficulty in conception | 0.086 (0.280) | 0.085 (0.279) |
| Acute maternal illness | Indicator (0,1) for any acute illnesses during pregnancy | 0.364*** (0.481) | 0.406 (0.491) |
| Chronic maternal illness | Indicator (0,1) for any chronic illnesses during pregnancy | 0.167*** (0.373) | 0.213 (0.409) |
| First trimester bleeding | Indicator (0,1) for vaginal bleeding in 1st trimester | 0.063*** (0.243) | 0.108 (0.311) |
| Live births | Number of previous live births | 1.994*** (2.067) | 2.448 (2.303) |
| Miscarriages/stillbirths | Number of spontaneous previous abortions/stillbirths | 0.287*** (0.615) | 0.376 (0.764) |
| Maternal age | Maternal age in years at delivery | 27.4*** (5.7) | 29.5 (6.8) |
| Maternal age squared | Maternal age in years at delivery squared | 781.4*** (334.8) | 914.4 (423.6) |
| Efficiency/Enabling Factors | |||
| Maternal education-Less than primary╞ | Indicator (0,1) for below primary school education | 0.149 (0.356) | 0.165 (0.372) |
| Maternal education-Incomplete secondary╞ | Indicator (0,1) for incomplete secondary school education | 0.249 (0.432) | 0.247 (0.432) |
| Maternal education-Secondary╞ | Indicator (0,1) for completed secondary school education | 0.174* (0.379) | 0.153 (0.361) |
| Maternal education-University╞ | Indicator (0,1) for attending university | 0.075 (0.263) | 0.065 (0.247) |
| Maternal employment | Indicator (0,1) for maternal employment status | 0.205 (0.404) | 0.212 (0.409) |
| Other Characteristics (some may affect both demand and infant health) | |||
| Native ancestry | Indicator (0,1) for native ancestry | 0.864* (0.343) | 0.88 (0.325) |
| European Latin ancestry | Indicator (0,1) for Latin European ancestry | 0.454 (0.498) | 0.456 (0.498) |
| European non-Latin ancestry | Indicator (0,1) for non-Latin European ancestry | 0.078 (0.268) | 0.078 (0.268) |
| Other ancestry | Indicator (0,1) for other ancestry | 0.041 (0.199) | 0.045 (0.207) |
| Male | Indicator (0,1) for a male sampled subject | 0.505 (0.5) | 0.516 (0.5) |
| Pregnancy year 95╪ | Indicator (0,1) for pregnancy in 1995 | 0.127 (0.333) | 0.123 (0.328) |
| Pregnancy year 96╪ | Indicator (0,1) for pregnancy in 1996 | 0.096 (0.295) | 0.103 (0.304) |
| Pregnancy year 97╪ | Indicator (0,1) for pregnancy in 1997 | 0.116 (0.320) | 0.11 (0.313) |
| Pregnancy year 98╪ | Indicator (0,1) for pregnancy in 1998 | 0.129 (0.335) | 0.125 (0.331) |
| Pregnancy year 99╪ | Indicator (0,1) for pregnancy in 1999 | 0.144 (0.351) | 0.143 (0.350) |
| Pregnancy year 00╪ | Indicator (0,1) for pregnancy in 2000 | 0.121 (0.327) | 0.124 (0.329) |
| Pregnancy year 01╪ | Indicator (0,1) for pregnancy in 2001 | 0.135 (0.342) | 0.142 (0.349) |
| Pregnancy year 02╪ | Indicator (0,1) for pregnancy in 2002 | 0.035 (0.184) | 0.044 (0.205) |
| Area Characteristics (province level) | |||
| Clinics concentration (2003) | Number of public clinics and hospitals per 100 Km2 in 2003 | 5.333 (7.218) | 5.105 (7.080) |
| Residents per hospital bed (1995) | Number of residents per public hospital bed in 1995 | 461.237 (93.239) | 465.593 (95.414) |
| Unemployment (2002) | Unemployment rate in 2002 in urban areas of the province | 21.084 (4.205) | 19.561 (3.310) |
| Female uninsured (2001) | % of females without public or private insurance in 2001 | 39.228* (9.825) | 39.701 (9.768) |
| Unmet basic needs (2001) | % of population in 2001 with basic needs unmet | 14.169*** (5.461) | 14.708 (5.729) |
Note: Standard Deviations are listed in parentheses.
╞
Omitted category is completed primary school
╪
Omitted category is year 1994. The decrease of frequency of pregnancy occurrence in 2002 is due to the fact that the sample included cases born in 1995 through 2002.
*, ** and *** indicate significant differences in the distribution of the variables between the samples of infants with and without birth defects at p<0.1, <0.05 and <0.01 respectively.