Explaining the 2001–2002 Infant Mortality Increase in the United States: Data from the Linked Birth/Infant Death Data Set

Regional and practitioner variations in reporting infant mortality

Objective: Assess regional differences in categorization of preterm delivery outcomes and impact on variation in reported infant mortality rates.Study design: A 27-item questionnaire was distributed to 1072 practitioners associated with U.S. birth hospitals. Five clinical scenarios were created to identify how participants classify delivery outcomes. Statistical analysis included Chi-square analysis and multinomial logistic regression.Results: 234 questionnaires were completed (response rate 22%). While >90% respondents classified a 14-week pregnancy loss with no sign of life as a miscarriage, only 22% would provide a fetal death certificate. Likewise, 37% would provide a certificate of live birth for a loss at 16 weeks with signs of life. There was notable regional variation in classifying these as live births (Northeast: 41%, Midwest: 44%, South: 13%, and West: 18%, p = .003).Conclusion: Regional practice variation in recording both live births and stillbirths was noted. Greater standardization in reporting practices may be warranted to improve the accuracy of reported birth outcomes in the U.S.

A Comparison of 3 Vitamin D Dosing Regimens in Extremely Preterm Infants: A Randomized Controlled Trial

OBJECTIVE

To determine the optimal dose of vitamin D supplementation to achieve biochemical vitamin D sufficiency in extremely low gestational age newborns in a masked randomized controlled trial.

STUDY DESIGN

100 infants 23 0/7-27 6/7 weeks gestation were randomized to vitamin D intakes of placebo (n = 36), 200 IU (n = 34), and 800 IU/d (n = 30) (approximating 200, 400, or 1000 IU/d, respectively, when vitamin D routinely included in parenteral or enteral nutrition is included). The primary outcomes were serum 25-hydroxy vitamin D concentrations on postnatal day 28 and the number of days alive and off respiratory support in the first 28 days.

RESULTS

At birth, 67% of infants had 25-hydroxy vitamin D <20 ng/mL suggesting biochemical vitamin D deficiency. Vitamin D concentrations on day 28 were (median [25th-75th percentiles], ng/mL): placebo: 22 (13-47), 200 IU: 39 (26-57), 800 IU: 84.5 (52-99); P < .001. There were no differences in days alive and off respiratory support (median [25th-75th percentiles], days): placebo: 1 (0-11), 200 IU: 0 (0-8), and 800 IU: 0.5 (0-22); P = .63, or other respiratory outcomes among groups.

CONCLUSIONS

At birth, most extremely preterm infants have biochemical vitamin D deficiency. This biochemical deficiency is reduced on day 28 by supplementation with 200 IU/d and prevented by 800 IU/d. Larger trials are required to determine if resolution of biochemical vitamin D deficiency improves clinical outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01600430.

Abortion and Infant Mortality on the First Day of Life

BACKGROUND

Fetal imaging for congenital anomalies increases pregnancy terminations late in gestation.

OBJECTIVES

We assessed whether late-pregnancy terminations can accidentally result in live births, and how these births impact infant mortality rates over time.

METHODS

We carried out a population-level analysis of 12,141 infant deaths in Quebec, Canada from 1986 to 2012. We calculated the proportion of infants born alive who died following pregnancy termination. The exposure was pregnancy termination with or without congenital anomaly recorded on death certificates. The main outcome was mortality on the first day of life by the hour.

RESULTS

Pregnancy termination was the cause of 19.4 infant deaths per 100,000 in 2000-2012, compared with 1.0 per 100,000 in 1986-1999. Most deaths after termination occurred in the first 3 h of life among infants with anomalies who weighed <500 g. In 2000-2012, infants who died following pregnancy termination led to an excess of 0.2 deaths per 1,000 on the first day of life, i.e. an 8.6% increase in the infant mortality rate (p value = 0.002).

CONCLUSIONS

Pregnancy termination in mid-gestation carries the risk of accidental live birth. These neonates increasingly affect infant mortality rates. Better recording is needed, including data on the prevention and management of accidental live births after pregnancy termination.

Dangers of death on the first day of life by the minute

OBJECTIVE

To evaluate mortality on the first day of life by minute and hour, and examine changes in major causes of death in the past three decades.

STUDY DESIGN

We evaluated mortality on the first day of life by the hour (0, 1, …, 23 h), and in the first hour by 5-min block (0-4, 5-9, …, 55-59 min) using data on cause of death for 15,690 infants in Canada from 1981 to 2012.

RESULTS

Infant mortality on the first day declined from 2.60 per 1000 in the 1980s to 1.26 in the 2000s. The decline was greater at 6-23 h than at 0-5 h of life, and among infants with congenital anomalies compared with prematurity and birth asphyxia.

CONCLUSION

Infant mortality is highest on the first day of life. More focus on prematurity and birth asphyxia in the first 5 h of life is needed to improve infant mortality.

Early childhood nutritional status in CARICOM countries: an overview with respect to five nutrition related millennium development goals

Previous reviews of nutritional status in children under 5 years describe the Caribbean grouped with Latin America. This paper focuses specifically on the Caribbean and the goals and targets of the Millennium Declaration that have bearing on childhood development. The results indicate that CARICOM countries have made progress in terms of child health as assessed by gross health indicators. Yet, the millennium generation experiences coexistence of undernutrition and overweight in early childhood. The associations of GNI with markers such as poverty indices are somewhat inconsistent with traditional findings and highlight a need to reassess the causes of infant mortality and low birth weight. However, a lack of systematic local data has hampered progress on an individual country basis. Interventions that deal more pointedly with country specific needs are required including those targeting obesity if the MDGs are to be attained by all member states.

Breastfeeding peer counselors as direct lactation care providers in the neonatal intensive care unit

In 2005, the Level III neonatal intensive care unit (NICU) at Rush University Medical Center initiated a demonstration project employing breastfeeding peer counselors, former parents of NICU infants, as direct lactation care providers who worked collaboratively with the NICU nurses. This article describes the conceptualization, implementation, and evaluation of this program and provides templates for other NICUs that wish to incorporate breastfeeding peer counselors with the goal of providing quality, evidence-based lactation care.

Annual summary of vital statistics: 2010-2011

The number of births in the United States declined by 1% between 2010 and 2011, to a total of 3 953 593. The general fertility rate also declined by 1% to 63.2 births per 1000 women, the lowest rate ever reported. The total fertility rate was down by 2% in 2011 (to 1894.5 births per 1000 women). The teenage birth rate fell to another historic low in 2011, 31.3 births per 1000 women. Birth rates also declined for women aged 20 to 29 years, but the rates increased for women aged 35 to 39 and 40 to 44 years. The percentage of all births to unmarried women declined slightly to 40.7% in 2011, from 40.8% in 2010. In 2011, the cesarean delivery rate was unchanged from 2010 at 32.8%. The preterm birth rate declined for the fifth straight year in 2011 to 11.72%; the low birth weight rate declined slightly to 8.10%. The infant mortality rate was 6.05 infant deaths per 1000 live births in 2011, which was not significantly lower than the rate of 6.15 deaths in 2010. Life expectancy at birth was 78.7 years in 2011, which was unchanged from 2010. Crude death rates for children aged 1 to 19 years did not change significantly between 2010 and 2011. Unintentional injuries and homicide were the first and second leading causes of death, respectively, in this age group. These 2 causes of death jointly accounted for 47.0% of all deaths of children and adolescents in 2011.

Toll-like receptor 4 mediates intrauterine growth restriction after systemic Campylobacter rectus infection in mice

Campylobacter rectus is associated with fetal exposure and low birthweight in humans. C. rectus also invades placental tissues and induces fetal intrauterine growth restriction (IUGR) in mice, along with overexpression of Toll-like receptors (TLR4), suggesting that TLR4 may mediate placental immunity and IUGR in mice. To test this hypothesis we examined the effect of in vitro TLR4 neutralization on trophoblastic proinflammatory activity and studied the IUGR phenotype in a congenic TLR4-mutant mouse strain after in vivo C. rectus infection. Human trophoblasts were pretreated with TLR4 neutralizing antibodies and infected with C. rectus; proinflammatory cytokine production was assessed by cytokine multiplex assays. Neutralizing TLR4 antibodies significantly impaired the production of proinflammatory cytokines in trophoblastic cells after infection in a dose-dependent manner. We used a subcutaneous chamber model to provide a C. rectus challenge in BALB/cAnPt (TLR4(Lps-d) ) and wild-type (WT) females. Females were mated with WT or TLR4(Lps-d) males once/week; pregnant mice were infected at (E)7.5 and sacrificed at (E)16.5 to establish IUGR phenotypes. Maternal C. rectus infection significantly decreased fetal weight/length in infected WT when compared with sham WT controls (P < 0.05, analysis of variance). However, infected TLR4(Lps-d -/-) mice did not show statistically significant differences in fetal weight and length when compared with WT controls (P > 0.05). Furthermore, heterozygous TLR4(Lps-d +/-) fetuses showed IUGR phenotype rescue. We conclude that TLR4 is an important mediator of trophoblastic proinflammatory responses and TLR4-deficient fetuses do not develop IUGR phenotypes after C. rectus infection, suggesting that placental cytokine activation is likely to be mediated by TLR4 during low birthweight/preterm birth pathogenesis.

Perinatal Outcome and Change in Body Mass Index in Mothers of Dichorionic Twins: A Longitudinal Cohort Study

We used a prospective cohort to analyze the effect of change in BMI rather than change in weight, in mothers carrying dichorionic twins from a population that did not receive any dietary intervention. A total of 269 mothers (150 nulliparas and 119 multiparas) were evaluated. The average change (%) from the pre-gravid BMI was 7.2 ± 6.1, 17.4 ± 8.2, and 28.7 ± 10.8, at 12–14, 22–25, and 30–34 weeks, respectively, without difference between nulliparas and multiparas. The comparison between maternities below or above the average change from the pregravid BMI failed to demonstrate an advantage (in terms of total twin birthweight and gestational age) of an above average change from the pregravid BMI, even when the lower versus upper quartiles were compared. Our observations reached different conclusions regarding the recommended universal dietary intervention in twin gestations. A cautious approach is advocated towards seemingly harmless excess weight gain, as normal weight women may turn overweight, or even obese, by the end of pregnancy, and be exposed to the untoward effects of obesity on future health and body image.

Annual summary of vital statistics: 2009

The number of births in the United States decreased by 3% between 2008 and 2009 to 4 130 665 births. The general fertility rate also declined 3% to 66.7 per 1000 women. The teenage birth rate fell 6% to 39.1 per 1000. Birth rates also declined for women 20 to 39 years and for all 5-year groups, but the rate for women 40 to 44 years continued to rise. The percentage of all births to unmarried women increased to 41.0% in 2009, up from 40.6% in 2008. In 2009, 32.9% of all births occurred by cesarean delivery, continuing its rise. The 2009 preterm birth rate declined for the third year in a row to 12.18%. The low-birth-weight rate was unchanged in 2009 at 8.16%. Both twin and triplet and higher order birth rates increased. The infant mortality rate was 6.42 infant deaths per 1000 live births in 2009. The rate is significantly lower than the rate of 6.61 in 2008. Linked birth and infant death data from 2007 showed that non-Hispanic black infants continued to have much higher mortality rates than non-Hispanic white and Hispanic infants. Life expectancy at birth was 78.2 years in 2009. Crude death rates for children and adolescents aged 1 to 19 years decreased by 6.5% between 2008 and 2009. Unintentional injuries and homicide, the first and second leading causes of death jointly accounted for 48.6% of all deaths to children and adolescents in 2009.

Variation by state in outcomes classification for deliveries less than 500 g in the United States

The purpose of this study is to explore state-level fetal death rates and <24 h infant mortality rates for deliveries less than 500 g in order to estimate outcomes classification differences at the edge of viability. We selected singleton deliveries to US resident mothers born <500 g and >20 weeks gestation from the NCHS live birth-infant death and fetal death files for 1999-2002 (n = 37,813). Infant deaths within 24 h of birth were selected to estimate odds of classification as a fetal death versus a live birth/infant death by state. Logistic regression was used to derive odds of classification as a fetal death and to adjust for maternal characteristics, calculating unadjusted and adjusted odds ratios. We identified 37,813 outcomes from 48 states reporting in this birthweight category. Unadjusted odds of classification of outcomes as a fetal death versus a live birth/death within 24 h by state ranged from OR = 0.38 (95% CI = 0.24-0.59) to OR = 2.93 (95% CI = 2.26-3.78); adjusted for maternal age and race, the range narrowed slightly to a OR = 0.31 (95% CI = 0.20-0.48) to aOR = 2.54 (95% CI = 1.96-3.30). Six states were more likely to classify outcomes as a live birth/infant death, while 14 states were more likely to classify as a fetal death, when compared to a large reference state. The remaining states did not differ significantly in their outcomes. The fraction of outcomes classified as fetal deaths varied by state during the years studied. This study suggests fetal death and early infant death outcomes reported for babies less than 500 g reflect differential classification thus influencing the validity of these vital statistics data at the state level. Further studies are needed to explore the factors that influence these differences.

Annual summary of vital statistics: 2007

The number of births in the United States increased between 2006 and 2007 (preliminary estimate of 4,317,119) and is the highest ever recorded. Birth rates increased among all age groups (15 to 44 years); the increase among teenagers is contrary to a long-term pattern of decline during 1991-2005. The total fertility rate increased 1% in 2007 to 2122.5 births per 1000 women. This rate was above replacement level for the second consecutive year. The proportion of all births to unmarried women increased to 39.7% in 2007, up from 38.5% in 2006, with increases noted for all race and Hispanic-origin groups and within each age group of 15 years and older. In 2007, 31.8% of all births occurred by cesarean delivery, up 2% from 2006. Increases in cesarean delivery were noted for most age groups and for non-Hispanic white, non-Hispanic black, and Hispanic women. Multiple-birth rates, which rose rapidly over the last several decades, did not increase during 2005-2006. The 2007 preterm birth rate was 12.7%, a decline of 1% from 2006. The low-birth-weight rate also declined in 2007 to 8.2%. The infant mortality rate was 6.77 infant deaths per 1000 live births in 2007, which is not significantly different from the 2006 rate. Non-Hispanic black infants continued to have much higher rates than non-Hispanic white and Hispanic infants. States in the southeastern United States had the highest infant and fetal mortality rates. The United States continues to rank poorly in international comparisons of infant mortality. Life expectancy at birth reached a record high of 77.9 years in 2007. Crude death rates for children aged 1 to 19 years decreased by 2.5% between 2006 and 2007. Unintentional injuries and homicide were the first and second leading causes of death, respectively, accounting for 53.7% of all deaths to children and adolescents in 2007.

An ecological approach to understanding black-white disparities in perinatal mortality

Despite appreciable improvement in the overall reduction of infant mortality in the United States, black infants are twice as likely to die within the first year of life as white infants, even after controlling for socioeconomic factors. There is consensus in the literature that a complex web of factors contributes to racial health disparities. This paper presents these factors utilizing the socioecological framework to underscore the importance of their interaction and its impact on birth outcomes of Black women. Based on a review of evidence-based research on Black-White disparities in infant mortality, we describe in this paper a missing potent ingredient in the application of the ecological model to understanding Black-White disparities in infant mortality: the historical context of the Black woman in the United States. The ecological model suggests that birth outcomes are impacted by maternal and family characteristics, which are in turn strongly influenced by the larger community and society. In addition to infant, maternal, family, community and societal characteristics, we present research linking racism to negative birth outcomes and describe how it permeates and is embedded in every aspect of the lives of African American women. Understanding the contribution of history to the various factors of life of Black women in the United States will aid in developing more effective policies and programs to reduce Black infant mortality.

The impact of nurse case management home visitation on birth outcomes in African-American women

The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Uniformed Services University of the Health Sciences, Department of the Navy, Department of Defense or the U. S. government. Dr. Wells is a military service member (employee of the U.S. government). This work was prepared as a part of her official duties. Title 17, USC Section 101 defines a U.S. government work as a work prepared by a military service member or employee of the U.S. government as part of the person's official duties. Despite substantial reductions in U.S. infant mortality rates, racial disparities persist, with black Americans experiencing 2.4 times the rate of their white counterparts. Low birthweight and preterm delivery contribute to this disparity.

METHODS

To examine the association between antepartum nurse case management home visitation and the occurrence of low birthweight and preterm deliveries in African-American women in Montgomery County, MD, a retrospective cohort study was conducted using existing data from 109 mothers who were enrolled in the Black Babies Start More Infants Living Equally Healthy (SMILE) program. Logistic regression analysis was used.

RESULTS

Women who received antepartum home visits were 0.37 (CI 0.15-0.94) times less likely to experience preterm delivery than women who did not receive antepartum home visits. The effect of antepartum home visits on preterm delivery was independent of level of prenatal care, negative life events and number of prior live births. There was no significant association between antepartum home visits and low birthweight.

CONCLUSION

Antepartum home visits appeared to be protective against preterm delivery and could contribute to reducing racial disparities in infant mortality. Further study is needed to understand and replicate specific program components that may contribute to improved birth outcomes in African-American women.

Annual summary of vital statistics: 2006

US births increased 3% between 2005 and 2006 to 4,265,996, the largest number since 1961. The crude birth rate rose 1%, to 14.2 per 1000 population, and the general fertility rate increased 3%, to 68.5 per 1000 women 15 to 44 years. Births and birth rates increased among all race and Hispanic-origin groups. Teen childbearing rose 3% in 2006, to 41.9 per 1000 females aged 15 to 19 years, the first increase after 14 years of steady decline. Birth rates rose 2% to 4% for women aged 20 to 44; rates for the youngest (10-14 years) and oldest (45-49) women were unchanged. Childbearing by unmarried women increased steeply in 2006 and set new historic highs. The cesarean-delivery rate rose by 3% in 2006 to 31.1% of all births; this figure has been up 50% over the last decade. Preterm and low birth weight rates also increased for 2006 to 12.8% and 8.3%, respectively. The 2005 infant mortality rate was 6.89 infant deaths per 1000 live births, not statistically higher than the 2004 level. Non-Hispanic black newborns continued to be more than twice as likely as non-Hispanic white and Hispanic infants to die in the first year of life in 2004. For all gender and race groups combined, expectation of life at birth reached a record high of 77.9 years in 2005. Age-adjusted death rates in the United States continue to decline. The crude death rate for children aged 1 to 19 years decreased significantly between 2000 and 2005. Of the 10 leading causes of death for children in 2005, only the death rate for cerebrovascular disease was up slightly from 2000, whereas accident and chronic lower respiratory disease death rates decreased. A large proportion of childhood deaths, however, continue to occur as a result of preventable injuries.

Black/white differences in very low birth weight neonatal mortality rates among New York City hospitals

OBJECTIVE

We sought to determine whether differences in the hospitals at which black and white infants are born contribute to black/white disparities in very low birth weight neonatal mortality rates in New York City.

METHODS

We performed a population-based cohort study using New York City vital statistics records on all live births and deaths of infants weighing 500 to 1499 g who were born in 45 hospitals between January 1, 1996, and December 31, 2001 (N = 11 781). We measured very low birth weight risk-adjusted neonatal mortality rates for each New York City hospital and assessed differences in the distributions of non-Hispanic black and non-Hispanic white very low birth weight births among these hospitals.

RESULTS

Risk-adjusted neonatal mortality rates for very low birth weight infants in New York City hospitals ranged from 9.6 to 27.2 deaths per 1000 births. White very low birth weight infants were more likely to be born in the lowest mortality tertile of hospitals (49%), compared with black very low birth weight infants (29%). We estimated that, if black women delivered in the same hospitals as white women, then black very low birth weight mortality rates would be reduced by 6.7 deaths per 1000 very low birth weight births, removing 34.5% of the black/white disparity in very low birth weight neonatal mortality rates in New York City. Volume of very low birth weight deliveries was modestly associated with very low birth weight mortality rates but explained little of the racial disparity.

CONCLUSION

Black very low birth weight infants more likely to be born in New York City hospitals with higher risk-adjusted neonatal mortality rates than were very low birth weight infants, contributing substantially to black-white disparities.

Trends in preterm-related infant mortality by race and ethnicity, United States, 1999-2004

Trends in preterm-related causes of death were examined by maternal race and ethnicity. A grouping of preterm-related causes of infant death was created by identifying causes that were a direct cause or consequence of preterm birth. Cause-of-death categories were considered to be preterm-related when 75 percent or more of total infant deaths attributed to that cause were deaths of infants born preterm, and the cause was considered to be a direct consequence of preterm birth based on a clinical evaluation and review of the literature. In 2004, 36.5 percent of all infant deaths in the United States were preterm-related, up from 35.4 percent in 1999. The preterm-related infant mortality rate for non-Hispanic black mothers was 3.5 times higher and the rate for Puerto Rican mothers was 75 percent higher than for non-Hispanic white mothers. The preterm-related infant mortality rate for non-Hispanic black mothers was higher than the total infant mortality rate for non-Hispanic white, Mexican, and Asian or Pacific Islander mothers. The leveling off of the U.S. infant mortality decline since 2000 has been attributed in part to an increase in preterm and low-birthweight births. Continued tracking of preterm-related causes of infant death will improve our understanding of trends in infant mortality in the United States.

The chasm in neonatal outcomes in relation to time of birth in Lebanon

PURPOSE

The purpose of this study was to investigate the relationship between the time of birth and the mortality and morbidity of infants admitted to neonatal intensive care units.

DESIGN

This prospective, cohort study examined the records of women and infants admitted to the NICUs of four hospitals in Beirut, Lebanon, between July 1, 2002, and June 30, 2003. The hospitals selected were university affiliated and had a large number of deliveries (5,152 total for the year 2002-2003).

MAIN OUTCOME VARIABLES

Neonatal mortality and morbidity for infants admitted to the NICU were evaluated in relation to time of birth.

RESULTS

For the whole sample, mortality was higher for infants born during the night shift than for those born during the day shift. Mortality, morbidity, and brain asphyxia rates were also higher for infants born during the night shift and admitted to the NICU. Maternal risk factors and delivery complications were nor consistently higher on the night shift.

Annual summary of vital statistics: 2005

The general fertility rate in 2005 was 66.7 births per 1000 women aged 15 to 44 years, the highest level since 1993. The birth rate for teen mothers (aged 15 to 19 years) declined by 2% between 2004 and 2005, falling to 40.4 births per 1000 women, the lowest ever recorded in the 65 years for which there are consistent data. The birth rates for women > or = 30 years of age rose in 2005 to levels not seen in almost 40 years. Childbearing by unmarried women also increased to historic record levels for the United States in 2005. The cesarean-delivery rate rose by 4% in 2005 to 30.2% of all births, another record high. The preterm birth rate continued to rise (to 12.7% in 2005), as did the rate for low birth weight births (8.2%). The infant mortality rate was 6.79 infant deaths per 1000 live births in 2004, not statistically different from the rate in 2003. Pronounced differences in infant mortality rates by race and Hispanic origin continue, with non-Hispanic black newborns more than twice as likely as non-Hispanic white and Hispanic infants to die within 1 year of birth. The expectation of life at birth reached a record high in 2004 of 77.8 years for all gender and race groups combined. Death rates in the United States continued to decline, with death rates decreasing for 9 of the 15 leading causes. The crude death rate for children aged 1 to 19 years did not decrease significantly between 2003 and 2004. Of the 10 leading causes of death for 2004 in this age group, only the rates for influenza and pneumonia showed a significant decrease. The death rates increased for intentional self-harm (suicide), whereas rates for other causes did not change significantly for children. A large proportion of childhood deaths continue to occur as a result of preventable injuries.

Infant mortality trends and differences between American Indian/Alaska Native infants and white infants in the United States, 1989-1991 and 1998-2000

OBJECTIVES

To describe changes in infant mortality rates, including birthweight-specific rates and rates by age at death and cause.

METHODS

We analyzed US linked birth/infant-death data for 1989-1991 and 1998-2000 for American Indians/Alaska Native (AIAN) and White singleton infants at > or =20 weeks' gestation born to US residents. We calculated birthweight-specific infant mortality rates (deaths in each birthweight category per 1000 live births in that category), and overall and cause-specific infant mortality rates (deaths per 100000 live births) in infancy (0-364 days) and in the neonatal (0-27 days) and postneonatal (28-364 days) periods.

RESULTS

Birthweight-specific infant mortality rates declined among AIAN and White infants across all birthweight categories, but AIAN infants generally had higher birthweight-specific infant mortality rates. Infant mortality rates declined for both groups, yet in 1998-2000, AIAN infants were still 1.7 times more likely to die than White infants. Most of the disparity was because of elevated post-neonatal mortality, especially from sudden infant death syndrome, accidents, and pneumonia and influenza.

CONCLUSIONS

Although birthweight-specific infant mortality rates and infant mortality rates declined among both AIAN and White infants, disparities in infant mortality persist. Preventable causes of infant mortality identified in this analysis should be targeted to reduce excess deaths among AIAN communities.

The contribution of preterm birth to infant mortality rates in the United States

OBJECTIVE

Although two thirds of infant deaths in the United States occur among infants born preterm (<37 weeks of gestation), only 17% of infant deaths are classified as being attributable to preterm birth with the standard classification of leading causes of death. To address this apparent discrepancy, we sought to estimate more accurately the contribution of preterm birth to infant mortality rates in the United States.

METHODS

We identified the top 20 leading causes of infant death in 2002 in the US linked birth/infant death file. The role of preterm birth for each cause was assessed by determining the proportion of infants who were born preterm for each cause of death and by considering the biological connection between preterm birth and the specific cause of death.

RESULTS

Of 27970 records in the linked birth/infant death file for 2002, the 20 leading causes accounted for 22273 deaths (80% of all infant deaths). Among infant deaths attributable to the 20 leading causes, we classified 9596 infant deaths (34.3% of all infant deaths) as attributable to preterm birth. Ninety-five percent of those deaths occurred among infants who were born at <32 weeks of gestation and weighed <1500 g, and two thirds of those deaths occurred during the first 24 hours of life.

CONCLUSIONS

On the basis of this evaluation, preterm birth is the most frequent cause of infant death in the United States, accounting for at least one third of infant deaths in 2002. The extreme prematurity of most of the infants and their short survival indicate that reducing infant mortality rates requires a comprehensive agenda to identify, to test, and to implement effective strategies for the prevention of preterm birth.

Persistent geographical disparities in infant mortality rates in Italy (1999-2001): comparison with France, England, Germany, and Portugal

BACKGROUND

Infant mortality rate (IMR) is used as a population health indicator. We provide an updated description of temporal and geographical trends of IMR in Italy.

METHODS

Regional data on infant deaths and live births were available for France, Germany, England, Portugal (1999-2000), and Italy (1990-2001). Mortality rates including 95% CIs and time-trends were computed.

RESULTS

IMR was 4.5 per 1000 live births in 1999-2001. Between 1999-2001 and 1990-1992 both neonatal and post-neonatal mortality rates declined (P < 0.05) but not the North/South ratio. In 1999-2000 the regional variability in IMR was higher in Italy than in other European countries.

CONCLUSION

Despite progresses in reducing IMR, geographical disparities persist within Italy.

Annual summary of vital statistics: 2004

The crude birth rate in 2004 was 14.0 births per 1000 population, the second lowest ever reported for the United States. The number of births and the fertility rate (66.3) increased slightly (by <1%) from 2003 to 2004. Fertility rates were highest for Hispanic women (97.7), followed by Asian or Pacific Islander (67.2), non-Hispanic black (66.7), Native American (58.9), and non-Hispanic white (58.5) women. The birth rate for teen mothers continued to fall, dropping 1% from 2003 to 2004 to 41.2 births per 1000 women aged 15 to 19 years, which is another record low. The teen birth rate has fallen 33% since 1991; declines were more rapid for younger teens aged 15 to 17 (43%) than for older teens aged 18 to 19 (26%). The proportion of all births to unmarried women is now slightly higher than one third. Smoking during pregnancy declined slightly from 2003 to 2004. In 2004, 29.1% of births were delivered by cesarean delivery, up 6% since 2003 and 41% since 1996 (20.7%). The primary cesarean delivery rate has risen 41% since 1996, whereas the rate of vaginal birth after a previous cesarean delivery has fallen 67%. The use of timely prenatal care was 84.0% in both 2003 and 2004. The percentage of preterm births rose to 12.5% in 2004 from 10.6% in 1990 and 9.4% in 1981. The percentage of low birth weight births also increased to 8.1% in 2004, up from 6.7% in 1984. Twin birth rate and triplet/+ birth rates increased by 1% and <1%, respectively, from 2002 to 2003. Multiple births accounted for 3.3% of all births in 2003. The infant mortality rate was 7.0 per 1000 live births in 2002 compared with 6.8 in 2001. The ratio of the infant mortality rate among non-Hispanic black infants to that for non-Hispanic white infants was 2.4 in 2002, the same as in 2001. The United States continues to rank poorly in international comparisons of infant mortality. Expectation of life at birth reached a record high of 77.6 years for all gender and race groups combined. Death rates in the United States continue to decline, with death rates decreasing for 8 of the 15 leading causes. Death rates for children < or =19 years of age declined for 7 of the 10 leading causes in 2003. The death rates did not increase for any cause, and rates for heart disease, influenza, and pneumonia and septicemia did not change significantly for children as a group. A large proportion of childhood deaths, however, continue to occur as a result of preventable injuries.

Annual summary of vital statistics--2003

The crude birth rate rose slightly in 2003 to 14.1 births per 1000 population, from 13.9 in 2002. The 2002 rate was the lowest ever reported for the United States. The total number of births and the fertility rate (66.1) also increased. The birth rate for teenaged mothers dropped 3% to another record low in 2003, to 41.7 per 1000 females aged 15 to 19 years. The teenage birth rate has fallen by one third since 1991. The birth rate declined for women 20 to 24 years old but rose for women aged 25 to 44 years. The number, rate, and proportion of births to unmarried women all increased in 2003. Smoking during pregnancy declined to 11%, down from 19.5% in 1989. Prenatal care utilization improved slightly for 2003; 84.1% of women began care in the first trimester of pregnancy. The cesarean delivery rate jumped 6% to 27.6% for another US high. The primary cesarean rate rose 6%, and the rate of vaginal birth after a previous cesarean delivery plummeted 16% from 2002 to 2003. The percent of infants delivered preterm continued to rise (12.3% in 2003). The preterm birth rate is up 16% since 1990. The percentage of children born at low birth weight rose slightly in 2003 to the highest level reported since 1970 (7.9%). The twinning rate increased, but the rate for triplet/+ births declined slightly between 2001 and 2002. Multiple births accounted for 3.3% of all births in 2002. The infant mortality rate rose to 7.0/1000 live births in 2002 from 6.8 in 2001, marking the first increase in this rate in >4 decades. Increases were distributed fairly widely across age, racial/ethnic groups, and geographic areas. The rise in infant mortality was attributed to increases in <750-g births in both singleton and multiple deliveries. Although the downward trend in infant mortality rates in many developed nations may have stabilized, the United States still ranked 27th among these nations in 2001. Expectation of life at birth reached a record high of 77.3 years for all gender and race groups combined in 2002. Death rates in the United States continue to decline. Between 2001 and 2002, death rates declined for the 3 leading causes of death: diseases of heart, malignant neoplasms, and cerebrovascular diseases. Death rates for children 1 to 19 years old decreased by 8% for suicide; the death rate for chronic lower respiratory diseases increased by 33% in 2002. Rates for unintentional injuries and homicide did not change significantly for children aged 1 to 19 years. A large proportion of childhood deaths continues to occur as a result of preventable injuries.