Hui-Lung Hsieh

Relationship of cesarean delivery to lower birth weight-specific neonatal mortality in singleton breech infants in the United States.

OBJECTIVE The preferred route of delivery for breech presentation has been controversial. We compared the birth weight-specific neonatal mortality of vaginal births to cesarean births in singleton births with breech presentation. METHODS A total of 371,692 singleton live births with breech presentation were selected for the study from the United States birth cohorts for the years 1989-1991. Differences in birth weight specific mortality were compared using a z-statistic for differences in proportions and by logistic regression. RESULTS Compared to primary vaginal births, primary cesarean births had significantly lower neonatal mortality for all birth weight groups, despite increased prevalence of fetal malformations in the cesarean as compared with vaginally delivered group. This mortality difference was greatest in the first hour of life. Difference in overall neonatal (less than 28 days) mortality rate ranged from a low of 1.6-fold in the 500-749 g group (726.6 per 1000 vaginal births compared with 456.3 per 1000 cesarean births, P < .001) to as high as about three-fold in the 1250-1499 g group (232.9 per 1000 vaginal births compared to 72.5 per 1000 cesarean births, P < .001). In the group with birth weights over 2500 g, neonatal mortality in the primary vaginal births was 5.3 per 1000 and in the primary cesarean births, 3.2 per 1000 (P < .001). Similarly, repeat cesarean births had significantly lower birth weight-specific neonatal mortality, compared with vaginal births after previous cesarean. CONCLUSION Singleton live births with breech presentation delivered by cesarean had lower birth weight-specific neonatal mortality as compared with vaginal births.

Trend in mortality from respiratory distress syndrome in the United States, 1970-1995☆☆☆

OBJECTIVE We examined the trend in mortality caused by respiratory distress syndrome (RDS) and its impact on changes in infant and neonatal mortality rates (IMR, NMR) in the United States. STUDY DESIGN Data on infant deaths in the United States for the period 1970 through 1995 were used to compare RDS-specific IMR to other cause-specific IMR. Data from the U.S. birth cohorts of 1985 through 1991 were used to examine birth weight- and RDS-specific NMRs. RESULTS IMR from RDS declined from 2.6 per 1000 live births in 1970 to 0.4 per 1000 in 1995. More than three quarters of this decline occurred between 1970 and 1985. RDS-specific NMR declined by 13% between 1985 and 1988 and by more than twofold greater, that is, 28%, between 1988 and 1991. There was also a significant reduction in postneonatal mortality from chronic lung diseases between 1988 and 1991. CONCLUSIONS Most of the reduction in mortality from RDS occurred before the introduction of surfactant therapy. The recent accelerated reduction in mortality from RDS between 1988 and 1991 was temporally associated with widespread use of surfactant therapy and was the single most important factor for reduction in overall NMR in the United States.

A survey of the newborn populations in Belgium, Germany, Poland, Czech Republic, Hungary, Bulgaria, Spain, Turkey, and Japan for the G985 variant allele with haplotype analysis at the medium chain Acyl-CoA dehydrogenase gene locus: Clinical and evolutionary consideration

Medium chain acyl-CoA dehydrogenase (MCAD) deficiency is an inborn error of fatty acid metabolism. It is one of the most frequent genetic metabolic disorders among Caucasian children. The G985 allele represented 90% of all the variant alleles of the MCAD gene in an extensive series of retrospective studies. To study the distribution of the G985 allele, newborn blood samples from the following countries were tested; 3000 from Germany (1/116). 1000 each from Belgium (1/77). Poland (1/98), Czech Republic (1/240). Hungary (1/168), Bulgaria (1/91), Spain (1/141). Turkey (1/216), and 500 from Japan (none). The frequency is shown in parentheses. The haplotype of G985 alleles in 1 homozygote and 57 heterozygote samples were then analyzed using two intragenic MCAD gene polymorphisms (Iaq1 and GT-repeat). The result indicated that only 1 of the 10 known haplotypes was associated with the G985 mutation, suggesting that G985 was derived originally from a single ancestral source. We made a compilation of the G985 frequencies in these countries and those in nine other European countries studied previously. The G985 distribution was high in the area stretching from Russia to Bulgaria in the east and in all northern countries in western and middle Europe, but low in the southern part of western and middle Europe. The incidence among ethnic Basques appeared to be low. This distribution pattern and the fact that all G985 alleles belong to a single haplotype suggest that G985 mutation occurred later than the delta F508 mutation of the CFTR, possibly in the neolithic or in a later period, and was brought into Europe by IndoEuropean-speaking people. The panEuropean distribution of the G985 allele, including Slavic countries from which patients with MCAD deficiency have rarely been detected, indicates the importance of raising the level of awareness of this disease.

Fetal death rate in the United States, 1979-1990: trend and racial disparity.

Objective To examine the impact of changes in birth weight distribution in individual groups and in birth weight-specific fetal death rates on the decline in the crude fetal death rate in the United States. Methods Data on live births and fetal deaths in the U.S. for the period 1979–1990 were examined by birth weight group and race using Kitagawas method for analysis of the crude fetal death rate. Results In the period 1979–1990, all racial groups had a decrease in the crude fetal death rate, more so in whites and others (about 22%) than in blacks (10%). In the white population, 73.4% of the total reduction in the crude fetal death rate was attributable to the improvement in birth weight-specific fetal death rates, and the remaining portion of the reduction was due to a favorable change in birth weight distribution. In the black population, the reduction in the crude fetal death rate was entirely attributable to the improvement in the birth weight-specific fetal death rates. However, in other groups, a favorable change in the birth weight distribution was the major determinant. Although black births represented 16.5% of all births in the U.S., they accounted for 26–29% of the crude fetal death rate. Disparity in the crude fetal death rates for blacks and whites is explained almost entirely by differences in birth weight distribution. Conclusion A further decrease in the crude fetal death rate in the U.S. requires a decrease in low birth weights, particularly in blacks.

Models for Determining Cost of Care and Length of Stay in Neonatal Intensive Care Units

New models for determining the cost of care and length of stay in the neonatal intensive care unit (NICU) were developed using financial and clinical data from 588 admissions to our NICU. The model for determining costs explained 71% of the variability in total hospital costs. Models such as the ones developed in this study can be used to compare costs in different institutions, determine temporal trends in costs, and examine the financial impact of using new technologies. Such models can also be useful components of a rational prospective pricing system for the NICU.

Multilevel Analysis of the Effects of Low-Income Residence on the Risk of LBW Associated with Advanced Maternal Age in African-Americans and Whites |[dagger]| 1366

Purpose: Advanced maternal age (AMA), or age greater than 34 years old, is a known risk factor for LBW among African Americans (AA) and whites. It has been suggested that this risk may be increased by conditions of social disadvantage. We hypothesized that exposure to poverty would increase the risk of LBW associated with AMA among both AA and whites. We utilized a multi-level analysis to assess whether income level of maternal residence would increase the risk of LBW associated with AMA, after adjusting for traditional individual risk factors.

Incidence and the risk of neonatal mortality due to meconium aspiration syndrome among African American and White infants with birth weights >= 2.5 kg. † 1249

Using Linked Infant Birth and Death data for the years 1990 and 1991, we compared incidence and the risk for neonatal mortality due to meconium aspiration syndrome (MEC-ASP) of infants born with birth weights >= 2.5 kg to African American and White mothers (N=7,054,404). Results of logistic regression models which included variables controlling for race of the mother and birth weight categories, showed that infants born to African American mothers were at an approximately 56% greater risk for a birth complicated by MEC-ASP [Adjusted Odds Ratio (OR): 1.56, 95% C.I., 1.50 - 1.61] as compared with White infants. In addition, for both racial groups, there was a significant increase in the risk for MEC-ASP as birth weight of the infants increased. For example, infants who weighed >= 4 kg had about a 54% increased risk for MEC-ASP as compared with infants who weighed 2.5 - 3.0 kg, after controlling for the effect of maternal race [Adjusted OR: 1.54, 95% C.I., 1.46 - 1.62]. For both African American and White infants, MEC-ASP was associated with an approximately 10 fold increase in the risk for neonatal mortality after adjustment for birth weight [Adjusted OR: 10.23, 95% C.I., 8.98 - 11.64). African Americans remained at 32% higher risk for neonatal mortality [Adjusted OR: 1.32, 95% C.I., 1.26 - 1.39) after controlling for the effects of birth weight and MEC-ASP.

Maternal Age-Adjusted Birth Prevalence of Down Syndrome Is Lower in States with Higher Levels of Per Capita Income

Maternal Age-Adjusted Birth Prevalence of Down Syndrome Is Lower in States with Higher Levels of Per Capita Income

Effect of Short (< 12 months) Interpregnancy Intervals on the Risk of Cause-Specific Infant Mortality Rates in the US

Effect of Short (< 12 months) Interpregnancy Intervals on the Risk of Cause-Specific Infant Mortality Rates in the US

Trends in neonatal mortality resulting from respiratory diseases in the United States, 1985-1991

Trends in neonatal mortality resulting from respiratory diseases in the United States, 1985-1991