Risk Factors For Infant Mortality Research Articles

The Perinatal Advantage of Mexican-Origin Latina Women

PURPOSE: To determine if there is a perinatal advantage for birth outcomes among Mexican-origin Latina (Latina) women compared to white non-Hispanic (white) women, after adjusting for maternal, paternal, and infant factors. METHODS: 1,439,583 births from the 1990–1993 California linked birth and infant death certificate data sets were analyzed for the risk of low birth weight infants and infant mortality. RESULTS: Latina women had a statistically higher unadjusted risk of low birth weight infants Odds Ratio OR = 1.07 and infant mortality OR = 1.08 compared to white women. After adjusting for potential confounders, Latina women had a similar risk of low birth weight infants OR = 0.98 and a lower risk of infant mortality OR = 0.88 relative to white women. In multivariate analyses, the most significant risk factor for low infant birth weight was young gestational age (OR = 82.91 for gestational age 1–230 days and OR = 10.62 for gestational age 231–258 days) and the most significant risk factor for infant mortality was low birth weight (OR = 53.99 for infant birth weight <500 grams and OR = 9.27 for infant birth weight 500–2499 grams). CONCLUSION: There was some evidence of a perinatal advantage for Latina women, when compared to white women and after adjusting for numerous potential confounders. To further reduce the risk of low birth weight infants and infant mortality, additional research is needed for etiologic clues beyond race/ethnicity and other traditional risk factors.

The effect of poverty, social inequity, and maternal education on infant mortality in Nicaragua, 1988-1993.

This study assessed the effect of poverty and social inequity on infant mortality risks in Nicaragua from 1988 to 1993 and the preventive role of maternal education. A cohort analysis of infant survival, based on reproductive histories of a representative sample of 10,867 women aged 15 to 49 years in León, Nicaragua, was conducted. A total of 7073 infants were studied; 342 deaths occurred during 6394 infant-years of follow-up. Outcome measures were infant mortality rate (IMR) and relative mortality risks for different groups. IMR was 50 per 1000 live births. Poverty, expressed as unsatisfied basic needs (UBN) of the household, increased the risk of infant death (adjusted relative risk [RR] = 1.49; 95% confidence interval [CI] = 1.15, 1.92). Social inequity, expressed as the contrast between the household UBN and the predominant UBN of the neighborhood, further increased the risk (adjusted RR = 1.74; 95% CI = 1.12, 2.71). A protective effect of the mother's educational level was seen only in poor households. Apart from absolute level of poverty, social inequity may be an independent risk factor for infant mortality in a low-income country. In poor households, female education may contribute to preventing infant mortality.

No fathers' names: a risk factor for infant mortality in the State of Georgia, USA

Abstract Many studies have explored maternal and infant factors as risks for infant mortality, but little attention is given to paternal factors. In Georgia, listing a father's name on the birth certificate is optional for married couples and possible after paternal acknowledgment for unmarried couples. The authors evaluated father's name reporting as a paternity measure and risk for infant mortality. Using the linked 1989–1990 birth and death certificates of singleton Georgia infants to calculate relative risks (RRs), infant mortality rates for 38,943 infants with no father's names listed were compared to rates for 178,100 with father's names listed. Compared with the rate for married women listing names, the death rates were higher for unmarried mothers not listing fathers (relative risk, RR=2.5; 95% CI 2.3–2.7), unmarried mothers listing fathers (RR=1.4; 95% CI 1.3–1.6), and married women not listing fathers (RR=2.3; 95% CI 1.6–3.1). Increased risks remained after stratifying by maternal race, age, adequacy of prenatal care and medical risks; and congenital malformations, birthweight, gestational age, and small-for-gestational age. Using logistic regression to examine for effect modification and to adjust for these factors together, the adjusted relative risks for death varied across different groups without fathers' names, regardless of marital status. For example, it remained statistically higher for infants with no father listed and without effect-modifying conditions such as low birthweight (estimated RR=2.0; 95% CI 1.6–2.4). Although these findings suggest paternal involvement, as measured by listing fathers' names, is protective against low birthweight and infant mortality, further evaluation is needed.

Risk factors for infant mortality in Down's syndrome: a nationwide study.

The aim of this study was to assess risk factors for the excessive infant mortality rates (IMR) of infants with Down's syndrome (DS). The study population included all 847 Jewish DS births in Israel during 1979-83 and 1987-91. Cases were identified through the National DS Registry. Data were abstracted from hospitalisation records. Ninety-one per cent of the DS diagnoses were confirmed by a cytogenetic analysis. The DS IMR were 24.3 times higher than in the general population. Major risk factors affecting DS IMRs were health status, time period of birth and residential arrangement of the infant. Other known risk factors for infant mortality, such as young maternal age, high birth order and low birthweight, had a weaker impact on IMR in the DS population. Our results imply that the current better survival of infants with DS is a function of the changing attitude towards this population. The study identifies a potential for further reduction in the mortality rates of DS infants, provided there is willingness to adopt a more active and supportive treatment and further changes in ethical codes of the public.

No fathers' names: a risk factor for infant mortality in the State of Georgia, USA

Many studies have explored maternal and infant factors as risks for infant mortality, but little attention is given to paternal factors. In Georgia, listing a father's name on the birth certificate is optional for married couples and possible after paternal acknowledgment for unmarried couples. The authors evaluated father's name reporting as a paternity measure and risk for infant mortality. Using the linked 1989–1990 birth and death certificates of singleton Georgia infants to calculate relative risks (RRs), infant mortality rates for 38,943 infants with no father's names listed were compared to rates for 178,100 with father's names listed. Compared with the rate for married women listing names, the death rates were higher for unmarried mothers not listing fathers (relative risk, RR=2.5; 95% CI 2.3–2.7), unmarried mothers listing fathers (RR=1.4; 95% CI 1.3–1.6), and married women not listing fathers (RR=2.3; 95% CI 1.6–3.1). Increased risks remained after stratifying by maternal race, age, adequacy of prenatal care and medical risks; and congenital malformations, birthweight, gestational age, and small-for-gestational age. Using logistic regression to examine for effect modification and to adjust for these factors together, the adjusted relative risks for death varied across different groups without fathers' names, regardless of marital status. For example, it remained statistically higher for infants with no father listed and without effect-modifying conditions such as low birthweight (estimated RR=2.0; 95% CI 1.6–2.4). Although these findings suggest paternal involvement, as measured by listing fathers' names, is protective against low birthweight and infant mortality, further evaluation is needed.

Birth outcome, not pregnancy process: Reply to van der Veen

In a recent article (Frisbie, Forbes, and Pullum 1996) we documented racial/ethnic differences in birth outcomes according to a more fine-grained classification than has typically been employed in the demographic literature. In his commentary, van der Veen focuses on the measurement of one of the dimensions of that classification, maturity of the infant, as proxied by the fetal growth ratio. The crux of the critique is easily seen in van der Veen's statement that "all of my disagreements with Frisbie et al.'s method arise from their particular use of a postnatal standard for the assessment of intrauterine growth." Our critic misunderstands our objective: He fails to realize our interest in birth outcome, not pregnancy process, and does not perceive that our intent was to extend the research extant in both the demographic and public-health literatures in which patently postnatal (i.e., ex utero) measures are taken as outcomes interesting in their own right and/or as risk factors for infant mortality and infant and childhood morbidity. Specifically, he does recognize that we purposefully expanded our focus to include moderately compromised births to determine if they were at higher risk than the normal births with whom they are conventionally categorized. Our discussion draws on research cited in the original article, on studies cited by our critic, and on a few more recent investigations. Although we have never argued that ours is the only, or even the best approach in all cases, we try to clarify the rationale for, and adduce additional empirical evidence of, the utility of the method we used.

The epidemiology of necrotizing enterocolitis infant mortality in the United States.

This study examined trends and risk factors for infant mortality associated with necrotizing enterocolitis in the United States. Necrotizing enterocolitis-associated deaths and infant mortality rates from 1979 through 1992 were determined by means of US multiple cause-of-death and linked birth/infant death data. Annual necrotizing enterocolitis infant mortality rates decreased from 1979 through 1986 but increased thereafter and were lower during the 3-year period before (1983 through 1985;11.5 per 100,000 live births) the introduction of surfactants than after (1990 through 1992; 12.3 per 100,000). Low-birthweight singleton infants who were Black male, or born to mothers younger than 17 had increased risk for necrotizing enterocolitis-associated death. As mortality among low-birth weight infants continues to decline and smaller newborns survive early causes of death, necrotizing enterocolitis-associated infant mortality may increase.

Maternal Marital Status as a Risk Factor for Infant Mortality

The increased risk of infant mortality associated with single motherhood is neither consistent among social and demographic subgroups nor inevitable, according to data from national linked birth and infant death files for 1983-1985. Maternal age is the only variable found to have a significant interaction with marital status among black mothers, and the risk associated with unmarried status increases with age. Among white mothers, age, educational level and receipt of prenatal care all show significant interactions with marital status; the increased risks of infant mortality attributed to unmarried motherhood are concentrated among subgroups usually thought to be at lower risk. For example, the risks of infant mortality among unmarried white women relative to married white women are highest among 25-29-year-olds. However, being unmarried did not affect the risk of infant mortality among babies born to college-educated white women.

Risk factors for infant mortality in nineteenth-century Sweden.

This study examines risk factors for infant mortality using individual-level data from a sample of parishes in northern Sweden in the nineteenth century. Sweden is of particular interest because of its unusually regular pattern of infant mortality decline during the century. We follow a sample of women longitudinally through their successive pregnancies and observe the mortality experience of each child. Exploratory and multivariate logistic regression analyses reveal an important intra-familial dimension to infant mortality that appears from the early stages of a woman's reproductive career. In addition, multivariate analyses by birth-order group suggest that ignoring intra-familial correlations of infant mortality may result in incorrect inferences. Siblings' shared probabilities of dying as infants suggest that high-birth-order children were not necessarily disadvantaged in any systematic way.

Early child health in Lahore, Pakistan: III. Maternal and family situation.

The family situation for mothers, in three areas differing in degree of urbanization and an upper middle class control group, in Lahore, Pakistan was described. Area differences in socio-economic, family composition, and housing and sanitary conditions were investigated. Data from a longitudinal sample (n = 1476 newborns) were compared with data from a cross-sectional population survey (n = 2998 families). Risk factors for child mortality and morbidity were common in the village and periurban slum area; conditions were somewhat better in the urban slum community. The sample was concluded to be representative of the population in the three areas and also for Pakistan in general. Two indices for cross-study comparisons were proposed, one for socio-economic background and the other for housing standard. The two indices were shown to be related to maternal weight for height at 9 months of pregnancy in the urban slum area; the socio-economic level was also functionally related to the weight for height measure in the village. The lower socio-economic and housing standard level, the lower was the mothers' relative weight just before childbirth. The findings were discussed in terms of risk factors for infant mortality, morbidity and psychological development.

β-Adrenergic Agonists for Preterm Labor

The infant mortality rate has become a benchmark in measuring progress toward U.S. health objectives. Approximately 40,000 infants die in the United States each year before reaching their first birthday. The overwhelming risk factor for infant mortality is low birth weight; indeed, two thirds of all infants who die before the age of one year weigh less than 2500 g at birth.1 During the 1980s there was a steady increase in the incidence of preterm delivery,2 the most important cause of low birth weight. Clearly, national strategies aimed at reducing infant mortality must include efforts to prevent preterm birth.On . . .

Outcome of Low Birth Weight Infants in a West African Village

Low birthweight (LBW) infants are at risk of increased mortality, impaired growth, and increased morbidity. We studied the progress of all LBW infants (less than 2.5 kg) born in a West African village where there is a resident pediatrician and midwife. There were 426 live births during the 8 years studied of which 42 (10 per cent) were of LBW. There were 17 infant deaths (IMR = 40/1000). Mean birthweight and gestation of infants dying in the first year were significantly lower than those of all live birth (2.33 kg v. 2.99 kg, P less than 0.001; 36.9 w v. 38.9 w, P less than 0.05). The mean weights of the 32 surviving LBW infants (15 preterm, 17 full term, small for gestational age) were compared with those of 32 full term, appropriate for gestational age matched controls over the first year. Growth velocities of paired groups were identical. The significant differences in weight at 1 year (P less than 0.005) reflected those at birth (P less than 0.001). There were no significant differences in clinic attendance rate or incidence of diarrhoea and respiratory disease between the four groups. We conclude that LBW is a strong risk factor for infant mortality, but not for diarrhoeal and respiratory morbidity in a community with ready access to obstetric and pediatric care.

Social class as a risk factor for infant mortality in an Australian population

Studies in other countries have identified social class as a risk factor for infant mortality. In Australia there is no systematic collection of population data by social class, partly due to the absence of a recognized measure. The use of occupational prestige as an indicator of social class is discussed and Australian prestige scales reviewed. In a population based study, logistic regression analysis of infant mortality in an Australian (NSW) population shows the effects of social class on infant mortality which remain when maternal age, marital status and parity are controlled.

Assessment of in utero hypoxia and risk of sudden infant death syndrome.

Few data are available on the role of hypoxia in sudden infant death syndrome (SIDS). The purpose of this study was to assess whether 10 antenatal factors consistent with in utero hypoxia were associated with an increased risk of SIDS. Cases and two sets of controls were chosen from the Upstate New York Live Birth Cohort for 1974 (n = 132,948). One hundred and forty-eight SIDS cases were identified, along with 114 dead controls made up of all other sudden deaths. Randomly selected live controls were frequency-matched to cases on mother's age, race, residence, parity, and infant's birthdate (n = 355). Data were collected from vital certificates (97% response), hospital delivery records (89%), and autopsy reports (100%). Odds ratios and 95% confidence intervals were calculated using Mantel-Haenszel techniques and logistic regression. Abnormal uterine bleeding was the only statistically significant (P less than 0.05) risk factor observed when dead controls were used (OR = 5.4). When live controls were used, statistically significant increases in risk were found for: placenta praevia (OR = 21.8), abruptio placentae (OR = 3.7), multiple birth (OR = 29.6), pregnancy interval less than or equal to 12 months (OR = 3.8), sexually transmitted disease (OR = 6.4), and eclampsia (OR = 17.7). These results lend support to a possible hypoxic aetiology of SIDS; however, differences by control group suggest that some factors are not specific to SIDS alone but may be risk factors for infant mortality in general.