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An Observational Study of Associations Among Maternal Fluids During Parturition, Neonatal Output, and Breastfed Newborn Weight Loss

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posted by carolbartle on 17 August 2011

New article in the International Breastfeeding Journal - significant for breastfeeding protection in maternity facilities.

  1. Maternal IV Fluids Linked to Newborns' Weight Loss

An Observational Study of Associations Among Maternal Fluids During Parturition, Neonatal Output, and Breastfed Newborn Weight Loss, International Breastfeeding Journal, August 15, 2011: Authors Joy Noel-Weiss, A Kirsten Woodend, Wendy E. Peterson, William Gibb and Dianne L. Groll.

Abstract (provisional) Open access provisional PDF     


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 ([less than or equal to]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.


2. Media report about the above study - Maternal IV Fluids Linked to Newborns' Weight Loss

ScienceDaily (Aug. 15, 2011) — A newborn baby's weight loss is often used to determine how well a baby is breastfeeding, and concern about a baby which loses too much weight may result in supplementing breastfeeding with formula. However, many women receive IV fluids during labor, and new research published in BMC's open access journal International Breastfeeding Journal shows that some of a newborn's initial weight loss may be due to the infant regulating its hydration and not related to a lack of breast milk.

A group of Canadian researchers looked at relationships among the IV fluids a mother received during labor (or prior to her caesarean section), neonatal output (measured by diaper weight), and newborn weight loss. They found that during the first 24 hours following birth there was a positive association both between the IV fluids given to mothers before birth and neonatal output, and between the neonatal output and newborn weight loss. At 60 hours post birth, the time of the average lowest weight, there was a positive relationship between maternal IV fluids and newborn weight loss.

"Nurses, midwives, lactation consultants, and doctors have long wondered why some babies lose substantially more weight than others even though all babies get small amounts to eat in the beginning," said principal investigator Prof Joy Noel-Weiss from the School of Nursing at the University of Ottawa's Faculty of Health Sciences. "It appears neonates exposed to increased fluids before birth might be born overhydrated, requiring the baby to regulate his or her fluid levels during the first 24 hours after birth."

Prof Noel-Weiss added, "We should reconsider the practice of using birth weight as the baseline when calculating newborn weight loss in the first few days following birth. For mothers and their breastfed babies, accurate assessment of weight loss is important. Although more research is needed, based on our findings, we would recommend using weight measured at 24 hours post birth as a baseline."

Alongside this article, the researchers have provided a standardized method for clinicians to collect and analyze data about newborn weight loss in their own maternity site, in the hope that this protocol will help them to make informed decisions when assessing newborn weight changes.


3.       Study protocol linked to the research - Iatrogenic newborn weight loss: knowledge translation using a study protocol for your maternity setting

Joy Noel-Weiss, A Kirsten Woodend & Dianne L Groll. International Breastfeeding Journal 2011, 6:10 doi:10.1186/1746-4358-6-10. Published: 15 August 2011. Link to provisional PDF -

Abstract (provisional)


In our original study of newborn weight loss, we determined there were positive correlations among newborn weight loss, neonatal output, and the IV fluids mothers received before their babies' birth. Basically, an increase in maternal IV fluids is correlated to an increase in neonatal output and newborn weight loss. When assessing newborn weight change, our recommendation is to change baseline from birth weight to a weight measured at 24 hours. The purpose of this paper is to provide a protocol for clinicians to collect and analyze data from their own maternity site to determine if the newborns experience such an iatrogenic weight loss and to make decisions about how to assess newborn weight changes.


We recommend a prospective observational study with data collected about maternal fluids, neonatal output, and newborn weight measurements. The methods we suggest include specifics about recruitment, data collection, and data analysis.


Quality assurance and research ethics considerations are described. We also share practical information that we learned from our original study. Ultimately, to encourage knowledge translation and research uptake, we provide a protocol and sound advice to do a research study in your maternity setting.