Despite efforts by obstetrical organizations and other groups over the years to reduce cesarean surgeries, the procedure continues to be performed in approximately one-in-three births in the United States. The study described here explores the possible benefits of increased hydration during labor and finds, via a well-designed meta-analysis, that giving low-risk, first-time mothers more fluids via intravenous (IV) therapy during labor reduces the number of cesarean sections, as well as the overall length of labor.
The news release offers readers a summary of the findings without much detail and, importantly, fails to note that the women included in the analysis cannot be generalized to all women in labor. The release does specify the absence of conflicts of interest among the principal investigators, an important transparency component.
Cesarean surgeries are invasive, complicated, and fraught with possible repercussions. They are life-saving when necessary, but critics have long argued that their use in the United States far exceeds normal parameters. Studies such as the one described here, if supported by additional research to explore the applicability to a wider general population, can contribute to better decision making on when to perform cesarean procedures.
Cost does not make an appearance in this release. The concept may seem trivial when considering the cheap ingredients in saline fluid, but little about American medical care is cheap.
Another important consideration is the cost of cesarean section compared with that of vaginal delivery, which is not addressed in the release.
Although the release offers a clear, succinct statement of the benefits provided by increased IV fluids, it provides no numbers describing the magnitude of those benefits. The research report on which the release is based found that the differences in number of cesarean procedures and in the duration of labor were real but relatively modest. For example, a c-section was deemed necessary for 12.5% of women who got higher levels of hydration and for 18.1% of those who received lower levels of fluids during labor. Length of labor declined by about an hour, a statistically significant but still modest clinically significant outcome.
An important potential risk of pulmonary edema (fluid build-up in the lungs) due to higher levels of intravenous hydration is not mentioned in the release, although it was reported in the article.
Additionally, the release neglects to explain that the only studies pooled for this analysis were those performed on low-risk, first-time mothers whose labor was not induced. The original research report notes that the effectiveness and safety of giving increased fluids to women who had given birth previously, whose labor was induced or who have other medical issues, is unclear. This is an important caveat that belongs in the news release.
The release explains that the data for these 1,215 women come from seven studies. But it didn’t note an important strength of those studies: they were all randomized, controlled trials. And it also omits a couple of worrying limitations: The combined sample size is still relatively small and, as explained in the original research report, only one of the studies was blinded.
The release doesn’t engage in disease mongering. It notes that cesarean surgery remains ubiquitous despite ongoing attempts by obstetrics organizations to reduce its incidence and, as a result, its accompanying risks. That’s important context.
The release doesn’t note funding sources but the research report indicates that the scientists received no financial support, a situation not uncommon when analyzing existing data. The release does explicitly state that none of the investigators has a conflict of interest.
The analysis compared increased levels of hydration during labor with levels used in “general practice in the United States.” That’s explained in the release.
The release suggests that some obstetricians already do — and more should — provide higher levels of fluids during labor.
The nature of this meta-analysis makes it clear that the effects of increased hydration have been the subject of past studies. What is new here is the meta-analytical approach.
Both the text wording and a quote from the lead researcher suggest that the results of this meta-analysis are applicable to all women in labor, a conclusion that is not supported by the original research report. Additionally, the source declares, early in the release, that the results of the analysis “are compelling and strongly argue for a change in practice.” Again, the limitations of the meta-analysis do not seem to warrant such prescriptive language.