School of Nursing, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada.
Int Breastfeed J. 2011 Aug 15;6:9. doi: 10.1186/1746-4358-6-9.
Newborn weight measurements are used as a key indicator of breastfeeding adequacy. The purpose of this study was to explore non-feeding factors that might be related to newborn weight loss. The relationship between the intravenous fluids women receive during parturition (the act of giving birth, including time in labour or prior to a caesarean section) and their newborn's weight loss during the first 72 hours postpartum was the primary interest.
In this observational cohort study, we collected data about maternal oral and IV fluids during labour or before a caesarean section. Participants (n = 109) weighed their newborns every 12 hours for the first three days then daily to Day 14, and they weighed neonatal output (voids and stools) for three days.
At 60 hours (nadir), mean newborn weight loss was 6.57% (SD 2.51; n = 96, range 1.83-13.06%). When groups, based on maternal fluids, were compared (≤1200 mls [n = 21] versus > 1200 [n = 53]), newborns lost 5.51% versus 6.93% (p = 0.03), respectively. For the first 24 hours, bivariate analyses show positive relationships between a) neonatal output and percentage of newborn weight lost (r(96) = 0.493, p < 0.001); and b) maternal IV fluids (final 2 hours) and neonatal output (r(42) = 0.383, p = 0.012). At 72 hours, there was a positive correlation between grams of weight lost and all maternal fluids (r(75) = 0.309, p = 0.007).
Timing and amounts of maternal IV fluids appear correlated to neonatal output and newborn weight loss. Neonates appear to experience diuresis and correct their fluid status in the first 24 hours. We recommend a measurement at 24 hours, instead of birth weight, for baseline when assessing weight change. Because practices can differ between maternity settings, we further suggest that clinicians should collect and analyze data from dyads in their care to determine an optimal baseline measurement.
新生儿体重测量被用作母乳喂养充足性的关键指标。本研究旨在探讨可能与新生儿体重下降有关的非喂养因素。在分娩过程中（分娩过程，包括劳动时间或剖腹产前）妇女接受的静脉输液与她们产后前 72 小时新生儿体重下降之间的关系是主要关注点。
在这项观察性队列研究中，我们收集了产妇在劳动或剖腹产前的口服和静脉输液数据。参与者（n=109）在头三天每 12 小时为新生儿称重一次，然后每天称重至第 14 天，并在三天内称重新生儿的尿量和粪便量。
在 60 小时（最低点），新生儿体重平均下降 6.57%（SD 2.51；n=96，范围 1.83-13.06%）。当根据产妇液体量进行比较时（≤1200 毫升[n=21]与>1200 毫升[n=53]），新生儿体重分别下降 5.51%和 6.93%（p=0.03）。在前 24 小时，双变量分析显示，a）新生儿尿量与新生儿体重下降百分比之间存在正相关关系（r（96）=0.493，p<0.001）；b）产妇静脉输液（最后 2 小时）与新生儿尿量之间存在正相关关系（r（42）=0.383，p=0.012）。在 72 小时时，丢失的克数与所有产妇液体量之间存在正相关关系（r（75）=0.309，p=0.007）。
产妇静脉输液的时间和量似乎与新生儿尿量和新生儿体重下降有关。新生儿在最初 24 小时内似乎经历利尿并纠正其液体状态。我们建议在评估体重变化时，以 24 小时时的体重而不是出生体重作为基线。由于不同的产科环境下的做法可能不同，我们进一步建议临床医生应该收集和分析他们所照顾的母婴对的数据，以确定最佳的基线测量值。
