Treatment of influenza

The tiniest babies: a registry of survivors with birth weight less than 400 grams

OBJECTIVE

The purpose of this project was to collect information on surviving infants with birth weights of <400 g.

METHODS

A Web-based registry was started in 2000 after searching for published reports of infants who survived to hospital discharge despite being born at <400 g. Fifteen cases were identified from scientific and lay print and Web-based publications. Parents, patients, and health providers were invited to submit data on additional infants. In the case of submissions from parents or patients, the information was confirmed by communication with a treating physician.

RESULTS

As of September 1, 2010, the Tiniest Babies Registry had compiled data on 110 patients born between 1936 and 2010. The number of infants who survived each year increased since the early 1990s. The infants in the registry weighed between 260 and 397 g at birth and had gestational ages from 21/7 to 34 weeks. Eighty-three (75%) of the patients are female. The 10 smallest infants are female, and the registry contains only 1 boy who was born weighing <300 g. The patients were born in 10 countries, including 80 (73%) born in the United States. The information on long-term functional outcome and health outcomes is limited. Many patients have ongoing health and learning concerns, and most of those for whom growth data are available remain short in stature and underweight for their age.

CONCLUSIONS

Survival of infants born weighing <400 g is rare but increasing. The Tiniest Babies Registry provides a repository for information about this remarkable group of infants.

The changing pattern of infant mortality in the US: the role of prenatal factors and their obstetrical implications

Infant mortality is one of the leading public health problems in the United States today. During the first half of this century the decline in infant mortality resulted largely from a reduction in postneonatal deaths (2-11 months after birth). Since 1950, two-thirds of all infant deaths have occurred in the neonatal period (1st month after birth). Since 1981, the rate of decline in the infant mortality rate has slowed due to a deterioration in the distribution of birthweights and a slowed improvement in birthweight-specific mortality rates. The role of birthweight is central to this issue, because low birthweight (LBW, < 2500 g) is a major determinant of death in the first year of life, particularly during the neonatal period. Stated another way, less than 0.5% of infants with birthweights > 2500 g die during the first year of life compared to 10.2% of infants with birthweights < 2500 g and 45.3% with birthweights < 1500 g (very low birthweight, VLBW). These effects are magnified when evaluated on a race-specific basis: the rate of LBW is twice as high and the rate of VLBW is three times as high for black infants compared to white infants. Reducing the rates of VLBW and LBW, particularly among blacks, holds the greatest potential for future reductions in infant mortality in the United States. The important role of maternal factors in the antecedents of infant mortality (VLBW, LBW, intrauterine growth retardation, preterm birth) have been clearly and repeatedly demonstrated. Some of these factors, such as maternal race, adverse obstetrical history and low level of education, are not amenable to change during pregnancy. Other factors, such as cessation of smoking, higher maternal weight gain and the initiation of early prenatal care have been shown to improve the course and outcome of pregnancy and subsequently result in reduced infant mortality.