McCormick M C
N Engl J Med. 1985 Jan 10;312(2):82-90. doi: 10.1056/NEJM198501103120204.
The low-birth-weight infant remains at much higher risk of mortality than the infant with normal weight at birth. In the neonatal period, when most infant deaths occur, the proportion of low-birth-weight infants, especially those with very low weight, is the major determinant of the magnitude of the mortality rates. Furthermore, differences in low-birth-weight rates account for the higher neonatal mortality rates observed in some groups, particularly those characterized by socioeconomic disadvantages. Much of the recent decline in neonatal mortality can be attributed to increased survival among low-birth-weight infants, apparently as a result of hospital-based services. The application of these services is currently considered cost-effective, although whether this will continue to be true in the future is unclear because of the increased survival of very tiny infants. Although low-birth-weight infants remain at increased risk of both postneonatal mortality and morbidity in infancy and early childhood, the risk is substantially smaller than that of neonatal death. In addition, these adverse later outcomes have not offset the gains achieved in the neonatal period. Nonetheless, the increased survival of high-risk infants raises concern about their future requirements for special medical and educational services and about the stress on their families. Despite increased access to antenatal services, only moderate declines in the proportion of low-birth-weight infants has been observed, and almost no change has occurred in the proportion of those with very low weight at birth. In addition, in many areas of the country the birth-weight-specific neonatal mortality rates are similar for groups at high and low risk of neonatal death. In view of these findings, continuation of the current decline in neonatal mortality and reduction of the mortality differentials between high- and low-risk groups require the identification and more effective implementation of strategies for the prevention of low-weight births.
低体重婴儿的死亡风险仍然比出生体重正常的婴儿高得多。在新生儿期，大多数婴儿死亡发生在这个阶段，低体重婴儿的比例，尤其是那些体重极低的婴儿，是死亡率高低的主要决定因素。此外，低体重率的差异导致了一些群体中观察到的较高新生儿死亡率，特别是那些具有社会经济劣势特征的群体。近期新生儿死亡率的下降很大程度上可归因于低体重婴儿存活率的提高，这显然是基于医院服务的结果。目前认为这些服务的应用具有成本效益，尽管由于极小婴儿存活率的提高，未来是否仍将如此尚不清楚。尽管低体重婴儿在婴儿期和幼儿期的新生儿后期死亡率和发病率风险仍然较高，但该风险远低于新生儿死亡风险。此外，这些后期不良后果并未抵消新生儿期所取得的成果。尽管如此，高危婴儿存活率的提高引发了对其未来特殊医疗和教育服务需求以及对其家庭压力的担忧。尽管获得产前服务的机会有所增加，但低体重婴儿的比例仅略有下降，出生时体重极低的婴儿比例几乎没有变化。此外，在该国许多地区，新生儿死亡高风险和低风险群体的按出生体重划分的新生儿死亡率相似。鉴于这些发现，要继续当前新生儿死亡率的下降趋势并缩小高风险和低风险群体之间的死亡率差异，就需要确定并更有效地实施预防低体重出生的策略。
