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Pregnancy Wheel Formula:
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The Pregnancy Wheel Calculator estimates the due date based on the last menstrual period (LMP) using the standard calculation of LMP plus 280 days. This method is widely used in obstetrics for pregnancy dating.
The calculator uses the pregnancy wheel formula:
Where:
Explanation: This calculation assumes a regular 28-day menstrual cycle and ovulation occurring on day 14. The 280 days represents 40 weeks of gestation.
Details: Accurate due date estimation is crucial for monitoring fetal development, scheduling prenatal tests, and determining the appropriate timing 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. The calculator will provide your estimated due date and current gestational age. Ensure the LMP date is accurate for the most reliable results.
Q1: How accurate is the LMP method?
A: The LMP method is generally accurate for women with regular 28-day cycles. For irregular cycles, ultrasound dating may be more precise.
Q2: What if I don't know my exact LMP?
A: If you're unsure of your LMP, an early pregnancy ultrasound (before 14 weeks) can provide a reliable due date estimate.
Q3: Why 280 days instead of 9 months?
A: Pregnancy is calculated as 40 weeks (280 days) from LMP, which is approximately 9 calendar months plus one week.
Q4: Can my due date change?
A: Yes, due dates may be adjusted based on ultrasound measurements, especially if there's a significant difference from the LMP-based calculation.
Q5: What percentage of babies are born on their due date?
A: Only about 5% of babies are born exactly on their due date. Most births occur within two weeks before or after the estimated date.