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French Pregnancy Calculation Formula:
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The French standard pregnancy calculation estimates the due date by adding 280 days to the first day of the last menstrual period (LMP). This method follows the Naegele's rule and is widely used in French healthcare system for pregnancy dating.
The calculator uses the French pregnancy calculation formula:
Where:
Explanation: This calculation assumes a regular 28-day menstrual cycle and ovulation occurring on day 14. The 280 days represent 40 weeks of gestation.
Details: Accurate pregnancy dating is crucial for monitoring fetal development, scheduling prenatal care, determining gestational age, and planning for delivery. It helps healthcare providers track appropriate fetal growth and identify potential complications.
Tips: Enter the first day of your last menstrual period in the date field. The calculator will automatically compute your estimated due date based on the French standard calculation of 280 days from LMP.
Q1: Why is 280 days used in French calculation?
A: 280 days represents 40 weeks of gestation, which is the standard duration used in French obstetrics based on Naegele's rule.
Q2: How accurate is this calculation method?
A: This method provides a good estimate but actual delivery dates can vary. Only about 5% of women deliver exactly on their estimated due date.
Q3: What if my menstrual cycle is irregular?
A: For irregular cycles, ultrasound dating in the first trimester is more accurate for determining gestational age and due date.
Q4: When should I confirm with ultrasound?
A: An early ultrasound between 8-12 weeks gestation can provide the most accurate dating and should be used to confirm or adjust the LMP-based due date.
Q5: Is this calculation different in other countries?
A: The basic principle is similar worldwide, but some countries may use 283 days or different calculation methods, though 280 days remains the French standard.