Noel-Weiss Joy, Courant Genevieve, Woodend A Kirsten
Open Med. 2008;2(4):e99-e110. Epub 2008 Oct 28.
Healthy, full-term, exclusively breastfed infants are expected to lose weight in the first days following birth. There are conflicting opinions about what constitutes a normal neonatal weight loss, and about when interventions such as supplemental feedings should be considered.
To establish the reference weight loss for the first 2 weeks following birth by conducting a systematic review of studies reporting birth weights of exclusively breastfed neonates.
We searched 5 electronic databases from June 2006 to June 2007: the Cochrane Database of Systematic Reviews; MEDLINE (from 1950); CINAHL (from 1982); EMBASE (from 1980); and Ovid HealthSTAR (from 1999). We included primary research studies with weight loss data for healthy, full-term, exclusively breastfed neonates in the first 2 weeks following birth.
Eleven studies met the inclusion criteria. Definitions, types of measurements, and reporting styles varied among studies. In most studies, daily weights were not measured and measurements did not continue for 2 weeks. Mean weight loss ranged from 5.7% to 6.6%, with standard deviations around 2%. Median percentage weight loss ranged from 3.2 to 8.3, with the majority around 6%. The majority of infants in these 11 studies regained their birth weight within the first 2 weeks postpartum. The second and third days following birth appear to be the days of maximum weight loss.
Methods used to report weight loss were inconsistent, using either an average of single lowest weights or a combination of weight losses. The 7% maximum allowable weight loss recommended in 4 clinical practice guidelines appears to be based on mean weight loss and does not account for standard deviation. Further research is needed to understand the causes of neonatal weight loss and its implications for morbidity and mortality.
健康的足月纯母乳喂养婴儿在出生后的头几天预计会体重减轻。关于什么构成正常的新生儿体重减轻以及何时应考虑进行诸如补充喂养等干预措施，存在相互矛盾的观点。
通过对报告纯母乳喂养新生儿出生体重的研究进行系统评价，确定出生后前两周的参考体重减轻情况。
我们在2006年6月至2007年6月期间检索了5个电子数据库：Cochrane系统评价数据库；MEDLINE（从1950年起）；CINAHL（从1982年起）；EMBASE（从1980年起）；以及Ovid HealthSTAR（从1999年起）。我们纳入了关于出生后前两周健康的足月纯母乳喂养新生儿体重减轻数据的原始研究。
11项研究符合纳入标准。研究之间的定义、测量类型和报告方式各不相同。在大多数研究中，未测量每日体重，且测量未持续2周。平均体重减轻范围为5.7%至6.6%，标准差约为2%。体重减轻百分比中位数范围为3.2至8.3，大多数约为6%。这11项研究中的大多数婴儿在产后前两周内恢复到出生体重。出生后的第二天和第三天似乎是体重减轻最多的日子。
用于报告体重减轻的方法不一致，使用的是单次最低体重的平均值或体重减轻的组合。4项临床实践指南中推荐的7%最大允许体重减轻似乎是基于平均体重减轻，未考虑标准差。需要进一步研究以了解新生儿体重减轻的原因及其对发病率和死亡率的影响。
