| Summary |
The "golden standard" of Naegele's Rule for determining the estimated date of delivery (EDD) has recently been challenged by early fetal ultrasound. The purpose of this study was to compare the accuracy of these two methods by testing the hypothesis, "There is a difference in accuracy when using Naegele's Rule and fetal ultrasound, when determining the EDD". The framework of the study was guided by midwifery philosophy. The study design was descriptive correlational. Naegele's Rule and fetal ultrasound were utilized as instrument measures. Retrospective review of 52 charts was done at a rural county health department, which offered prenatal care by Certified Nurse-Midwives (CNM's). A data collection tool included sample criteria, dating criteria, demographic data, and special events during labor and delivery, allowing for the analysis of possible trends in the sample in regard to the variables being examined. Chi-square analysis showed no significant difference (alpha level 0.05) between the two measurement methods when viewed in the context of delivering within 14 days of the established EDD (p = 0.46). A comparison of the mean number of days from the EDD to the actual date of delivery of both measurement methods demonstrated Naegele's Rule to be more accurate by 1.4 hours. Unexpected findings revealed increased maternal age to have a negative impact on the accuracy of EDD determination when using both Naegele's Rule (p = .01) and fetal ultrasound (p = .007), while multigravidae had a negative impact when utilizing fetal ultrasound (p = .04). Results of this study have implications for midwives, and other prenatal health care providers, by statistically demonstrating Naegele's Rule to be as accurate a method as fetal ultrasound for EDD establishment, when the last normal menstrual period is known. Suggestions for future study include study replication with changes to strengthen its validity, and further investigation of the effects of age and gravidae on EDD accuracy. With midwifery philosophy advocating non-technological intervention in normal processes, midwives are encouraged to explore this issue. |
