4.3 Limitations
The main limitation of this study was inadequate documentation of
maternal fluid balance. This limitation has been encountered by other
researchers investigating intrapartum IV fluids practices. (11, 31, 32)
In our study inadequate documentation necessitated the exclusion of
certain cases and the assumption of consistent IV fluids administration
rates continued between bags. Whilst this approached helped to mitigate
selection bias and uphold the study’s internal validity, there remains
the potential that non-differential misclassification of IV fluids
volume occurred. Moreover, the necessity to categorise IV fluids intake
into two groups may have diluted our findings and increased the risk of
a Type 2 error (failing to reject a false null hypothesis).
A second limitation of this study was the visual estimation of maternal
blood loss. Maternal blood loss at birth can be underestimated when
visual estimation is used.(7, 33) Consequently, maternal blood loss may
have been systematically underestimated, particularly given the
infrequent documentation of cumulative blood loss within the initial 24
hours postpartum.