(771) A natural experiment: impact of IV fluid restriction on labor outcomes

Prior studies have found mixed results on the impact of IV fluid administration and labor outcomes. Following Hurricane Helene in September 2024, there was a nationwide IV fluid shortage due to flooding of a main production facility. As a result, our labor & delivery unit modified fluid protocols to use normal saline instead of lactated ringers and administer fluids at 50 cc/hr instead of 125 cc/hr. This provides a natural experiment to assess the impact of IV fluid use on labor outcomes. 

Study Design:
The fluid protocol was changed on October 16, 2024. This is a retrospective analysis examining fluid utilization and labor outcomes before (7/1/24 – 10/16/24) and after (10/17/24-1/31/25) the change in fluid protocol. All deliveries in our unit that labored (i.e. excluding scheduled cesareans) were included. Statistics were conducted in Stata.  

Results:
There was a significant decrease in fluid usage in the 3 months after the fluid shortage compared to the 3 months before (5.2 bags of 500 ml of fluid per delivery vs 3.7; p < 0.001) (Figure 1). There was no difference in labor duration (16.9 vs 16.3 hours, p = 0.92), cesarean delivery (23.0% vs 25.5%, p = 0.19), acute kidney injury (AKI) (1.4% vs 1.6%, p = 0.66) or postpartum hemorrhage (PPH, quantitative blood loss > 1 liter) (16.0% vs 18.0%, p = 0.21) in the before vs. after cohorts respectively (Table 1). There was a decrease in rate of intra-amniotic infection (IAI) diagnosed after the shortage (10.8 % vs 8.2%, p = 0.04) but no difference in rates of NICU admission for term infants (3.7 % vs 4.0%, p = 0.52). 

Conclusion:

Despite a large and significant drop in fluid use during the IV fluid shortage, we found no difference in labor duration, cesarean delivery or other labor outcomes. The only significant change was a slight decrease in IAI, which is potentially spurious and unlikely to be related to decreased fluid administration. These results suggest that decreasing fluid utilization does not affect labor outcomes. This may encourage more conservative use of a critical medical resource and an opportunity for cost savings for labor & delivery units.