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Wheel EDD Calculation:
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The Wheel EDD (Estimated Due Date) calculation is a standard method used in obstetrics to determine the expected delivery date based on the first day of the last menstrual period (LMP). This method adds 280 days (40 weeks) to the LMP date.
The calculator uses the Wheel EDD formula:
Where:
Explanation: This calculation assumes a regular 28-day menstrual cycle and ovulation occurring on day 14. The 280 days represents the typical human gestation period from the first day of the last menstrual period.
Details: Accurate due date calculation is essential for proper prenatal care, monitoring fetal development, planning for delivery, and identifying potential complications such as post-term pregnancy.
Tips: Enter the first day of your last menstrual period in the date field. The calculator will provide your estimated due date and current gestation period. Ensure the date is accurate for the most reliable result.
Q1: How accurate is the Wheel EDD calculation?
A: The Wheel EDD is accurate for women with regular 28-day cycles. Only about 5% of women deliver on their exact due date, but most deliver within 2 weeks before or after.
Q2: What if my cycle is longer or shorter than 28 days?
A: For irregular cycles, the due date may need adjustment. Typically, add or subtract the difference from 28 days to get a more accurate estimate.
Q3: When is an ultrasound more accurate than LMP?
A: Early pregnancy ultrasound (before 14 weeks) is often more accurate than LMP dating, especially if the LMP date is uncertain or cycles are irregular.
Q4: Why 280 days instead of 9 months?
A: 280 days equals 40 weeks, which is the standard medical calculation. Calendar months vary in length, so weeks provide more precise tracking.
Q5: Can the due date change during pregnancy?
A: Yes, healthcare providers may adjust the due date based on early ultrasound measurements or if fetal growth doesn't match the LMP-based timeline.