by Anne Eglash MD, IBCLC, FABM
How much water should a breastfeeding mother drink? There are many factors that determine the amount of fluid that a person needs, such as body weight, level of activity, sweating, ambient temperature, dietary intake (soup vs salty crackers!), illness such as diarrhea, etc. Typical advice has been to drink according to thirst, but unfortunately some women do not have great ‘thirst mechanisms’ and they look for guidance. In addition to the risk of dehydration, chronic insufficient fluid intake can lead to chronic kidney disease, constipation, low energy, and difficulty with blood sugar control.
The National Collegiate Athletic Association recommends a urine color chart for athletes to assess adequate hydration. A group of researchers wanted to know if this same urine color chart could be used to assess hydration in pregnant and nursing mothers. They collected urine from women during their pregnancy and lactation and compared the urine color with the typical lab measures that are used to determine hydration status, such as urine osmolality.
What do you think is accurate about breastfeeding and assessing fluid intake, according to these researchers? Choose 1 or more:
- Breastfeeding women lose approximately 400-800ml of water through their breastmilk each day.
- Breastfeeding women tend to have darker urine than athletes with the same hydration status because of breastmilk proteins excreted into urine.
- A urine color chart is an accurate, simple tool to guide a breastfeeding mother on her hydration status.
- A urine color chart should not be used for breastfeeding women because if she keeps her urine as dilute as an athlete’s, her milk will become too dilute with water.
See the Answer
Ann Nutr Metab. 2017;70 Suppl 1:18-22. doi: 10.1159/000462999. Epub 2017 Jun 15
Monitoring Body Water Balance in Pregnant and Nursing Women: The Validity of Urine Color
McKenzie AL1, Armstrong LE.
BACKGROUND:
Urine osmolality (UOSM) reflects the renal regulation of excess fluid or deficit fluid, and therefore, serves as a marker of hydration status. Little is known about monitoring hydration in pregnant and lactating women despite significant physiological challenges to body water balance during that time. Therefore, we designed a study to assess if urine color (UCOL), an inexpensive and practical method, was a valid means of assessing urine concentration. Twenty-four hour UCOL was significantly correlated with 24 h UOSM in all women: pregnant, lactating, and control (r = 0.61-0.84, all p < 0.001). Utilizing a receiver operating characteristic statistical analysis, we found that 24 h and single sample UCOL had excellent diagnostic accuracy for identifying UOSM ≥500 mOsm·kg-1 in all women (area under the curve = 0.68-0.95, p < 0.001-0.46), and the UCOL that reflected this cut off was ≥4 on the UCOL chart.
SUMMARY:
Therefore, UCOL is a valid marker of urine concentration and ultimately hydration status in pregnant, lactating, and non-pregnant, non-lactating women. For pregnant, lactating, and control women, the UCOL chart is a valid tool that can be used to monitor urine concentration in a single sample or over the course of the day via a 24 h sample. Key Message: Women who present with a UCOL of 4 or more likely have a UOSM ≥500 mOsm·kg-1. Given the positive health benefits associated with UOSM <500 mOsm·kg-1, women should aim for a 1, 2, or 3 on the UCOL chart. If a UCOL of ≥4 is observed, women should consider increasing fluid consumption to improve hydration status.
Milk Mob Comment by Anne Eglash MD, IBCLC, FABM
Breastfeeding women do not have extra measurable protein in their urine, nor should they have darker urine as compared to non-breastfeeding individuals or athletes. In addition, high water intake will not dilute her breastmilk. The breasts tightly regulate how much water goes into the breastmilk, so that if a woman drinks excess water, it should not affect her breastmilk. Insufficient water intake will affect her own health status before it alters her milk volume or quality, unless she is very dehydrated.
According to these authors, using the urine color chart designed to monitor hydration status in athletes is a simple and reliable tool for pregnant and nursing mothers to determine their own fluid status. A downloadable urine color chart recommended in the Position Statement and Recommendations for Hydration to Minimize Risk of Dehydration and Heat Illness by the National Federation of State High School Associations is available.
The researchers found that a urine color of 1-3 on this chart is reassuring for adequate hydration status. Many pregnant and breastfeeding mothers would probably welcome receiving a color copy of this urine chart, since they often are unsure of how to assess their fluid status in their new physiologic state.
Please note that this color chart will not be reliable for women who are taking ingesting medications that change the urine color, such as high doses of B vitamins.
Basma Ismail
Very informative
Mary
Very interesting! Thanks for sharing. Please also emphasize that women do not need to overhydrate. A friend told me her milk supply was dropping – she had been told it was important to drink lots of water, and as her supply dropped, she was working on drinking more water. I can’t remember how much she was drinking, but it was a very large amount. I told her I had read that overhydration could negatively impact milk supply and that perhaps she could try cutting back so that urine was dilute, but that she wasn’t forcing herself to drink so much. (She was already feeding as soon as home from work, spending extra time skin to skin on the weekends, etc.) Her milk supply increased when she decreased her fluid intake, but monitored to make sure urine was light color.
Hend Fayez
very informative
Ruth
The urine color chart for athletes seems like a good way to reminded of proper fluid intake for a breastfeeding mother. However, many mothers take some sort of vitamin or supplement that may cause the color to change thus making this an unreliable measure.
Anne Eglash
Yes, some supplements, particularly high dose vitamin B supplements, are well known to cause a major change to urine color. I am not aware that a large % breastfeeding mothers are taking vitamins that markedly distort the color of their urine.