1. What is the Pregnancy Due Date Calculator?

The Pregnancy Due Date Calculator estimates the expected delivery date (EDD) based on the first day of the last menstrual period (LMP). This calculation follows Naegele's rule, which adds 280 days (40 weeks) to the LMP date.

2. How Does the Calculator Work?

The calculator uses the standard obstetric formula:

Where:

• \( EDD \) — Estimated Due Date
• \( LMP \) — Last Menstrual Period (first day)
• \( 280 \text{ days} \) — Standard pregnancy duration (40 weeks)

Explanation: This calculation assumes a regular 28-day menstrual cycle and ovulation occurring on day 14. The due date represents the end of the 40th week of pregnancy.

3. Importance of Due Date Calculation

Details: Accurate due date estimation is essential 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.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period in the date field. Ensure the date is accurate for the most reliable due date estimation. The calculator will provide the estimated delivery date based on the standard 280-day pregnancy duration.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this due date calculation?
A: This method is accurate for women with regular 28-day cycles. Only about 5% of babies are born exactly on their due date, with most deliveries occurring within two weeks before or after.

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 due date. For shorter cycles, subtract the difference. An ultrasound in early pregnancy can provide a more accurate due date.

Q3: Why is pregnancy calculated from LMP rather than conception?
A: LMP is used because it's typically easier to recall than the exact conception date. This creates the apparent paradox of being "2 weeks pregnant" at conception.

Q4: Can the due date change during pregnancy?
A: Yes, healthcare providers may adjust the due date based on early ultrasound measurements, which are most accurate in the first trimester.

Q5: What percentage of babies are born on their due date?
A: Only about 4-5% of babies are born exactly on their calculated due date. Most births occur between 37 and 42 weeks of pregnancy.