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Perinatology EDD Calculation:
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The Perinatology Estimated Due Date (EDD) Calculator calculates the expected delivery date based on the last menstrual period (LMP) using the standard formula of LMP plus 280 days (40 weeks).
The calculator uses the standard obstetric formula:
Where:
Explanation: This calculation is based on Naegele's rule, which assumes a 28-day menstrual cycle and ovulation occurring on day 14.
Details: Accurate EDD calculation is crucial for proper prenatal care, monitoring fetal development, scheduling important tests, and preparing for delivery. It helps healthcare providers track pregnancy progress and identify potential complications.
Tips: Enter the first day of your last menstrual period in the date field. Ensure the date is accurate for the most reliable EDD calculation. The calculator will provide the estimated due date based on the standard 280-day pregnancy duration.
Q1: How accurate is the LMP-based EDD calculation?
A: LMP-based calculation is accurate for women with regular 28-day cycles. For irregular cycles, ultrasound dating in the first trimester is more reliable.
Q2: What if my menstrual cycle is longer or shorter than 28 days?
A: For cycles longer than 28 days, add the extra days to the EDD. For shorter cycles, subtract the difference. Early ultrasound can provide more accurate dating.
Q3: Can the EDD change during pregnancy?
A: Yes, EDD may be adjusted based on first-trimester ultrasound measurements, which are more accurate than LMP dating alone.
Q4: What percentage of babies are born on their EDD?
A: Only about 4-5% of babies are born exactly on their EDD. Most births occur between 37-42 weeks gestation.
Q5: When should I contact my healthcare provider about EDD?
A: Contact your provider for confirmation of EDD and discuss any discrepancies between LMP dating and ultrasound dating early in pregnancy.